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Journal articles on the topic 'Cell compartment'
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1
Vance, J. E., D. Pan, D. E. Vance, and R. B. Campenot. "Biosynthesis of membrane lipids in rat axons." Journal of Cell Biology 115, no. 4 (November 15, 1991): 1061–68. http://dx.doi.org/10.1083/jcb.115.4.1061.
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Compartmented cultures of sympathetic neurons from newborn rats were employed to test the hypothesis that the lipids required for maintenance and growth of axonal membranes must be synthesized in the cell body and transported to the axons. In compartmented cultures the distal axons grow into a compartment separate from that containing the cell bodies and proximal axons, in an environment free from other contaminating cells such as glial cells and fibroblasts. There is virtually no bulk flow of culture medium or small molecules between the cell body and axonal compartments. When [methyl-3H]choline was added to the cell body-containing compartment the biosynthesis of [3H]-labeled phosphatidylcholine and sphingomyelin occurred in that compartment, with a gradual transfer of lipids (less than 5% after 16 h) into the axonal compartment. Surprisingly, addition of [methyl-3H]choline to the compartment containing only the distal axons resulted in the rapid incorporation of label into phosphatidylcholine and sphingomyelin in that compartment. Little retrograde transport of labeled phosphatidylcholine and sphingomyelin (less than 15%) into the cell body compartment occurred. Moreover, there was minimal transport of the aqueous precursors of these phospholipids (e.g., choline, phosphocholine and CDP-choline) between cell compartments. Similarly, when [3H]ethanolamine was used as a phospholipid precursor, the biosynthesis of phosphatidylethanolamine occurred in the pure axons, and approximately 10% of the phosphatidylethanolamine was converted into phosphatidylcholine. Experiments with [35S]methionine demonstrated that proteins were made in the cell bodies, but not in the axons. We conclude that axons of rat sympathetic neurons have the capacity to synthesize membrane phospholipids. Thus, a significant fraction of the phospholipids supplied to the membrane during axonal growth may be synthesized locally within the growing axon.
2
Kodym, Reinhard. "A Mathematical Model, Describing the Kinetic Behaviour of the Thrombopoietic System in Mice and Rats." Alternatives to Laboratory Animals 22, no. 4 (July 1994): 269–84. http://dx.doi.org/10.1177/026119299402200407.
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A mathematical model of thrombopoiesis in small rodents, principally rats, is presented. It is a compartmental model, consisting of seven compartments, which contain the following cell populations: early megakaryocyte progenitor cells, late megakaryocyte progenitor cells, megakaryocytes of ploidy classes 8N, 16N, 32N and 64N, and platelets. Signals for feedback regulation are derived from the platelet compartment and from all megakaryocyte compartments. The main characteristic of the model is its ability to simulate megakaryocyte ploidy and volume distribution. Platelet number and the ploidy distribution of megakaryocytes after acute and chronic disturbances in the platelet compartment were simulated and were found to approximate experimental data published in the literature. The kinetic parameters for the progenitor cell compartment, which were derived from published in vitro data, were sufficient to stimulate the platelet number after administration of hydroxyurea and 5-fluorouracil. The proposed model is capable of reproducing the reactions of the system to several experimental disturbances in the thromobopoietic lineage, but the action of agents such as radiation, which cause damage to the stem cells or to other lineages, cannot be simulated.
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Afonso, Anne Marie Roque, Jiaji Jiang, François Penin, Claire Tareau, Didier Samuel, Marie-Anne Petit, Henri Bismuth, Elisabeth Dussaix, and Cyrille Féray. "Nonrandom Distribution of Hepatitis C Virus Quasispecies in Plasma and Peripheral Blood Mononuclear Cell Subsets." Journal of Virology 73, no. 11 (November 1, 1999): 9213–21. http://dx.doi.org/10.1128/jvi.73.11.9213-9221.1999.
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ABSTRACT The existence of an extrahepatic reservoir of hepatitis C virus (HCV) is suggested by differences in quasispecies composition between the liver, peripheral blood mononuclear cells, and serum. We studied HCV RNA compartmentalization in the plasma of nine patients, in CD19+, CD8+, and CD4+ positively selected cells, and also in the negatively selected cell fraction (NF). HCV RNA was detected in all plasma samples, in seven of nine CD19+, three of eight CD8+, and one of nine CD4+ cell samples, and in seven of eight NF cells. Cloning and sequencing of HVR1 in two patients showed a sequence grouping: quasispecies from a given compartment (all studied compartments for one patient and CD8+ and NF for the other) were statistically more genetically like each other than like quasispecies from any other compartment. The characteristics of amino acid and nucleotide substitutions suggested the same structural constraints on HVR1, even in very divergent strains from the cellular compartments, and homogeneous selection pressure on the different compartments. These findings demonstrate the compartmental distribution of HCV quasispecies within peripheral blood cell subsets and have important implications for the study of extrahepatic HCV replication and interaction with the immune system.
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Bassler, Kevin, Jonas Schulte-Schrepping, Stefanie Warnat-Herresthal, Anna C. Aschenbrenner, and Joachim L. Schultze. "The Myeloid Cell Compartment—Cell by Cell." Annual Review of Immunology 37, no. 1 (April 26, 2019): 269–93. http://dx.doi.org/10.1146/annurev-immunol-042718-041728.
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Myeloid cells are a major cellular compartment of the immune system comprising monocytes, dendritic cells, tissue macrophages, and granulocytes. Models of cellular ontogeny, activation, differentiation, and tissue-specific functions of myeloid cells have been revisited during the last years with surprising results; for example, most tissue macrophages are yolk sac derived, monocytes and macrophages follow a multidimensional model of activation, and tissue signals have a significant impact on the functionality of all these cells. While these exciting results have brought these cells back to center stage, their enormous plasticity and heterogeneity, during both homeostasis and disease, are far from understood. At the same time, the ongoing revolution in single-cell genomics, with single-cell RNA sequencing (scRNA-seq) leading the way, promises to change this. Prevailing models of hematopoiesis with distinct intermediates are challenged by scRNA-seq data suggesting more continuous developmental trajectories in the myeloid cell compartment. Cell subset structures previously defined by protein marker expression need to be revised based on unbiased analyses of scRNA-seq data. Particularly in inflammatory conditions, myeloid cells exhibit substantially vaster heterogeneity than previously anticipated, and work performed within large international projects, such as the Human Cell Atlas, has already revealed novel tissue macrophage subsets. Based on these exciting developments, we propose the next steps to a full understanding of the myeloid cell compartment in health and diseases.
5
Inadome, Hironori, Yoichi Noda, Hiroyuki Adachi, and Koji Yoda. "Immunoisolaton of the Yeast Golgi Subcompartments and Characterization of a Novel Membrane Protein, Svp26, Discovered in the Sed5-Containing Compartments." Molecular and Cellular Biology 25, no. 17 (September 1, 2005): 7696–710. http://dx.doi.org/10.1128/mcb.25.17.7696-7710.2005.
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ABSTRACT The Golgi apparatus consists of a set of vesicular compartments which are distinguished by their marker proteins. These compartments are physically separated in the Saccharomyces cerevisiae cell. To characterize them extensively, we immunoisolated vesicles carrying either of the SNAREs Sed5 or Tlg2, the markers of the early and late Golgi compartments, respectively, and analyzed the membrane proteins. The composition of proteins was mostly consistent with the position of each compartment in the traffic. We found six uncharacterized but evolutionarily conserved proteins and named them Svp26 (Sed5 compartment vesicle protein of 26 kDa), Tvp38, Tvp23, Tvp18, Tvp15 (Tlg2 compartment vesicle proteins of 38, 23, 18, and 15 kDa), and Gvp36 (Golgi vesicle protein of 36 kDa). The localization of Svp26 in the early Golgi compartment was confirmed by microscopic and biochemical means. Immunoprecipitation indicated that Svp26 binds to itself and a Golgi mannosyltransferase, Ktr3. In the absence of Svp26, a considerable portion of Ktr3 was mislocalized in the endoplasmic reticulum. Our data suggest that Svp26 has a novel role in retention of a subset of membrane proteins in the early Golgi compartments.
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Mastroberti, Alexandra A., and Jorge Ernesto de Araujo Mariath. "Compartmented cells in the mesophyll of Araucaria angustifolia (Araucariaceae)." Australian Journal of Botany 51, no. 3 (2003): 267. http://dx.doi.org/10.1071/bt00045.
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The compartmented cells of the immature and mature leaves of young and adult plants of Araucaria angustifolia (Bert.) O. Ktze. are characterised by the presence of pectinous partitions in the cell lumen, forming a system of compartments. The function of these cells is possibly related to water storage and translocation. The morphology of compartmented cells differs from that of immature and mature leaves: at the time of maturity the compartment system or secretion is more defined. These cells undergo the programmed cell death (PCD) process, because they are enucleated in adult plants. The compartmented cells' cytology and pectic composition are similar to the mucilage cells of Lauraceae and Cactaceae.
7
Kalaidzidis, Inna, Marta Miaczynska, Marta Brewińska-Olchowik, Anna Hupalowska, Charles Ferguson, Robert G. Parton, Yannis Kalaidzidis, and Marino Zerial. "APPL endosomes are not obligatory endocytic intermediates but act as stable cargo-sorting compartments." Journal of Cell Biology 211, no. 1 (October 12, 2015): 123–44. http://dx.doi.org/10.1083/jcb.201311117.
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Endocytosis allows cargo to enter a series of specialized endosomal compartments, beginning with early endosomes harboring Rab5 and its effector EEA1. There are, however, additional structures labeled by the Rab5 effector APPL1 whose role in endocytic transport remains unclear. It has been proposed that APPL1 vesicles are transport intermediates that convert into EEA1 endosomes. Here, we tested this model by analyzing the ultrastructural morphology, kinetics of cargo transport, and stability of the APPL1 compartment over time. We found that APPL1 resides on a tubulo-vesicular compartment that is capable of sorting cargo for recycling or degradation and that displays long lifetimes, all features typical of early endosomes. Fitting mathematical models to experimental data rules out maturation of APPL1 vesicles into EEA1 endosomes as a primary mechanism for cargo transport. Our data suggest instead that APPL1 endosomes represent a distinct population of Rab5-positive sorting endosomes, thus providing important insights into the compartmental organization of the early endocytic pathway.
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de Celis, J. F., and M. Ruiz-Gomez. "groucho and hedgehog regulate engrailed expression in the anterior compartment of the Drosophila wing." Development 121, no. 10 (October 1, 1995): 3467–76. http://dx.doi.org/10.1242/dev.121.10.3467.
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Drosophila imaginal discs are divided into units called compartments. Cells belonging to the same compartment are related by lineage and express a characteristic set of ‘selector genes’. The borders between compartments act as organizing centres that influence cell growth within compartments. Thus, in the cells immediately anterior to the anterior-posterior compartment boundary the presence of the hedgehog product causes expression of decapentaplegic, which, in turn, influences the growth and patterning of the wing disc. The normal growth of the disc requires that posterior-specific genes, such as hedgehog and engrailed are not expressed in cells of the anterior compartment. Here we show that hedgehog can activate engrailed in the anterior compartment and that both hedgehog and engrailed are specifically repressed in anterior cells by the activity of the neurogenic gene groucho. In groucho mutant discs, hedgehog and engrailed are expressed at the dorsoventral boundary of the anterior compartment, leading to the ectopic activation of decapentaplegic and patched and to a localised increase in cell growth associated with pattern duplications. The presence of engrailed in the anterior compartment causes the transformation of anterior into posterior structures.
9
Saraste, Jaakko, and Bruno Goud. "Functional Symmetry of Endomembranes." Molecular Biology of the Cell 18, no. 4 (April 2007): 1430–36. http://dx.doi.org/10.1091/mbc.e06-10-0933.
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In higher eukaryotic cells pleiomorphic compartments composed of vacuoles, tubules and vesicles move from the endoplasmic reticulum (ER) and the plasma membrane to the cell center, operating in early biosynthetic trafficking and endocytosis, respectively. Besides transporting cargo to the Golgi apparatus and lysosomes, a major task of these compartments is to promote extensive membrane recycling. The endocytic membrane system is traditionally divided into early (sorting) endosomes, late endosomes and the endocytic recycling compartment (ERC). Recent studies on the intermediate compartment (IC) between the ER and the Golgi apparatus suggest that it also consists of peripheral (“early”) and centralized (“late”) structures, as well as a third component, designated here as the biosynthetic recycling compartment (BRC). We propose that the ERC and the BRC exist as long-lived “mirror compartments” at the cell center that also share the ability to expand and become mobilized during cell activation. These considerations emphasize the functional symmetry of endomembrane compartments, which provides a basis for the membrane rearrangements taking place during cell division, polarization, and differentiation.
10
Provance, D. W., A. McDowall, M. Marko, and K. Luby-Phelps. "Cytoarchitecture of size-excluding compartments in living cells." Journal of Cell Science 106, no. 2 (October 1, 1993): 565–77. http://dx.doi.org/10.1242/jcs.106.2.565.
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By fluorescence ratio imaging of large and small inert tracer particles in living cells, we have previously shown that particles 24 nm in radius are excluded from otherwise uncharacterized compartments in the distal and perinuclear cytoplasm (Luby-Phelps, K. and Taylor, D.L., 1988. Cell Motil. Cytoskel. 10, 28–37). In this study we examined the cytoarchitecture of these compartments. Whole-mount TEM showed that distal size-excluding compartments were devoid of membrane-bounded organelles and were filled with a dense cytomatrix consisting of numerous, long bundles of thin filaments interconnected by a more random meshwork of short thin filaments. The mean diameter of void spaces in the cytomatrix of distal excluding compartments was 31 nm, compared to 53 nm in adjacent non-excluding domains. The height of the distal excluding compartments was generally < or = 50% of the height in the adjacent non-excluding compartment. An electron-dense structure having the same projected outline as the perinuclear size-excluding compartment was visible by whole-mount TEM, but the cells were too thick and osmiophilic in this region to resolve any detail. Immunofluorescence localization of cytoskeletal proteins in distal excluding compartments indicated the presence of filament bundles containing F-actin nonmuscle filamin (ABP280) and alpha-actinin. F-actin and ABP280, but not alpha-actinin, were found also in between these filament bundles. Microtubules and vimentin generally were rare or absent from distal excluding domains. Staining of living cells with DMB-ceramide revealed that the perinuclear size-excluding compartment consisted of a compact, juxtanuclear domain coinciding with the trans-Golgi, surrounded by a more diffuse domain coinciding with a perinuclear concentration of endoplasmic reticulum. Intense immunofluorescence staining for vimentin was also observed in the perinuclear size-excluding compartment. We propose that the most likely mechanism for exclusion from distal compartments is molecular sieving by a meshwork of actin filament bundles interconnected by an F-actin/ABP280 gel network, while exclusion from the perinuclear compartment may be due to close apposition of cisternae in the trans-Golgi and a network or basket of vimentin filaments in the centrosomal region of the cell.
11
Miller, K., J. Beardmore, H. Kanety, J. Schlessinger, and C. R. Hopkins. "Localization of the epidermal growth factor (EGF) receptor within the endosome of EGF-stimulated epidermoid carcinoma (A431) cells." Journal of Cell Biology 102, no. 2 (February 1, 1986): 500–509. http://dx.doi.org/10.1083/jcb.102.2.500.
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We have followed the internalization pathway of both epidermal growth factor (EGF) and its receptor in human epidermoid carcinoma (A431) cells. Using EGF conjugated with horseradish peroxidase and anti-receptor monoclonal antibodies (TL5 and EGFR1) coupled either directly or indirectly to colloidal gold we have identified an extensive elaboration of endosomal compartments, consisting of a peripheral branching network of tubular cisternae connected to vacuolar elements that contain small vesicles and a pericentriolar compartment consisting of a tubular cisternal network connected to multivesicular bodies. Immunocytochemistry on frozen thin sections using receptor-specific antibody-gold revealed that at 4 degrees C in the presence of EGF, receptors were mainly on the plasma membrane and, to a lesser extent, within some elements of both the peripheral and pericentriolar endosomal compartments. Upon warming to 37 degrees C there was an EGF-dependent redistribution of most binding sites, first to the peripheral endosome compartment and then to the pericentriolar compartment and lysosomes. Upon warming only to 20 degrees C the ligand-receptor complex accumulated in the pericentriolar compartment. Acid phosphatase cytochemistry identifies hydrolytic activity only within secondary lysosomes and trans cisternae of the Golgi stacks. Together these observations suggest that the prelysosomal endosome compartment extends to the pericentriolar complex and that the transfer of EGF receptor complexes to the acid phosphatase-positive lysosome involves a discontinuous, temperature-dependent step.
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Xiao, Changting, V. Margaret Quinton, and John P. Cant. "Description of glucose transport in isolated bovine mammary epithelial cells by a three-compartment model." American Journal of Physiology-Cell Physiology 286, no. 4 (April 2004): C792—C797. http://dx.doi.org/10.1152/ajpcell.00356.2003.
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Initial rates of glucose entry into isolated bovine mammary epithelial cells display moderate degrees of asymmetry and cooperative interactions between export and import sites. The present study examined the hypothesis that these kinetic features are due to compartmentalization of intracellular glucose. Net uptake of 3- O-methyl-d-[1-3H]glucose (3-OMG) by isolated bovine mammary epithelial cells was measured at 37°C. The time course of 3-OMG net uptake was better fitted by a double-exponential equation than by a single- or triple-exponential equation. Compartmental analysis of the time course curve suggested that translocated 3-OMG is distributed into two compartments with fractional volumes of 32.6 ± 5.7% and 67.4 ± 5.7%, respectively. The results support the view that glucose transport in bovine mammary epithelial cells is a multistep process consisting of two serial steps: fast, carrier-mediated, symmetric translocation of sugar across the cell plasma membrane into a small compartment and subsequent slow exchange of posttranslocated sugar between two intracellular compartments. A three-compartment model of this system successfully simulated the observed time course of 3-OMG net uptake and the observed dependence of unidirectional entry rates on intra- and extracellular 3-OMG concentrations. Simulations indicated that backflux of radiolabeled sugar from the small compartment to extracellular space during 15 s of incubation gives rise to the apparent asymmetry, trans-stimulation, and cooperativity of mammary glucose transport kinetics. The fixed-site carrier model overestimated the rate of glucose accumulation in cells, and its features can be accounted for by the compartmentalization of intracellular sugar.
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Naik, Haley B., Melissa Beshire, Breda M. Walsh, Jingjing Liu, and David I. Soybel. "Secretory state regulates Zn2+ transport in gastric parietal cell of the rabbit." American Journal of Physiology-Cell Physiology 297, no. 4 (October 2009): C979—C989. http://dx.doi.org/10.1152/ajpcell.00577.2008.
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Secretory compartments of neurons, endocrine cells, and exocrine glands are acidic and contain high levels of labile Zn2+. Previously, we reported evidence that acidity is regulated, in part, by the content of Zn2+ in the secretory [i.e., tubulovesicle (TV)] compartment of the acid-secreting gastric parietal cell. Here we report studies focusing on the mechanisms of Zn2+ transport by the TV compartment in the mammalian (rabbit) gastric parietal cell. Uptake of Zn2+ by isolated TV structures was monitored with a novel application of the fluorescent Zn2+ reporter N-(6-methoxy-8-quinolyl)- para-toluenesulfonamide (TSQ). Uptake was suppressed by removal of external ATP or blockade of H+-K+-ATPase that mediates luminal acid secretion. Uptake was diminished with dissipation of the proton gradient across the TV membrane, suggesting Zn2+/H+ antiport as the connection between Zn2+ uptake and acidity in the TV lumen. In isolated gastric glands loaded with the reporter fluozin-3, inhibition of H+-K+-ATPase arrested the flow of Zn2+ from the cytoplasm to the TV compartment and secretory stimulation with forskolin enhanced vectorial movement of cytoplasmic Zn2+ into the tubulovesicle/lumen (TV/L) compartment. Our findings suggest that Zn2+ accumulation in the TV/L compartment is physiologically coupled to secretion of acid. These findings offer novel insight into mechanisms regulating Zn2+ homeostasis in the gastric parietal cell and potentially other cells in which acidic subcellular compartments serve signature functional roles.
14
Lawrence, P. A., J. Casal, and G. Struhl. "The hedgehog morphogen and gradients of cell affinity in the abdomen of Drosophila." Development 126, no. 11 (June 1, 1999): 2441–49. http://dx.doi.org/10.1242/dev.126.11.2441.
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The adult abdomen of Drosophila is a chain of anterior (A) and posterior (P) compartments. The engrailed gene is active in all P compartments and selects the P state. Hedgehog enters each A compartment across both its anterior and posterior edges; within A its concentration confers positional information. The A compartments are subdivided into an anterior and a posterior domain that each make different cell types in response to Hedgehog. We have studied the relationship between Hedgehog, engrailed and cell affinity. We made twin clones and measured the shape, size and displacement of the experimental clone, relative to its control twin. We varied the perceived level of Hedgehog in the experimental clone and find that, if this level is different from the surround, the clone fails to grow normally, rounds up and sometimes sorts out completely, becoming separated from the epithelium. Also, clones are displaced towards cells that are more like themselves: for example groups of cells in the middle of the A compartment that are persuaded to differentiate as if they were at the posterior limit of A, move posteriorly. Similarly, clones in the anterior domain of the A compartment that are forced to differentiate as if they were at the anterior limit of A, move anteriorly. Quantitation of these measures and the direction of displacement indicate that there is a U-shaped gradient of affinity in the A compartment that correlates with the U-shaped landscape of Hedgehog concentration. Since affinity changes are autonomous to the clone we believe that, normally, each cell's affinity is a direct response to Hedgehog. By removing engrailed in clones we show that A and P cells also differ in affinity from each other, in a manner that appears independent of Hedgehog. Within the P compartment we found some evidence for a U-shaped gradient of affinity, but this cannot be due to Hedgehog which does not act in the P compartment.
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Johnson, A. O., R. N. Ghosh, K. W. Dunn, R. Garippa, J. Park, S. Mayor, F. R. Maxfield, and T. E. McGraw. "Transferrin receptor containing the SDYQRL motif of TGN38 causes a reorganization of the recycling compartment but is not targeted to the TGN." Journal of Cell Biology 135, no. 6 (December 15, 1996): 1749–62. http://dx.doi.org/10.1083/jcb.135.6.1749.
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The SDYQRL motif of the cytoplasmic domain of TGN38 is involved in targeting TGN38 from endosomes to the TGN. To create a system for studying this pathway, we replaced the native transferrin receptor (TR) internalization motif (YTRF) with the SDYQRL TGN-targeting motif. The advantages of using TR as a reporter molecule include the ability to monitor trafficking, in both biochemical and microscopy experiments, using the natural ligand transferrin. When expressed in CHO cells, the SDYQRL-TR construct accumulated in juxtanuclear tubules and vesicles that are in the vicinity of the TGN. The SDYQRL-TR-containing structures, however, do not colocalize with TGN markers (e.g., NBD ceramide), and therefore the SDYQRL motif is not sufficient to target the TR to the TGN. The morphology of the SDYQRL-TR-containing juxtanuclear structures is different from the recycling compartment found in cells expressing the wild-type TR. In addition, the SDYQRL-TR-containing juxtanuclear compartment is more acidic than the recycling compartment in cells expressing the wild-type TR. The juxtanuclear compartment, however, is a bona fide recycling compartment since SDYQRL-TR was recycled back to the cell surface at a rate comparable to the wild-type TR, and sphingomyelin and cellubrevin, both of which label all compartments of the endocytic recycling pathway, colocalize with SDYQRL-TR in the juxtanuclear structures. These findings demonstrate that expression of the SDYQRL-TR construct alters the morphology and pH of endocytic recycling compartments rather than selectively affecting the intracellular trafficking pathway of the SDYQRL-TR construct. Therefore, the SDYQRL trafficking motif is not simply a molecular address that targets proteins to the TGN, but it can play an active role in determining the physical characteristics of endosomal compartments.
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Graham, T. R., and S. D. Emr. "Compartmental organization of Golgi-specific protein modification and vacuolar protein sorting events defined in a yeast sec18 (NSF) mutant." Journal of Cell Biology 114, no. 2 (July 15, 1991): 207–18. http://dx.doi.org/10.1083/jcb.114.2.207.
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The sec18 and sec23 secretory mutants of Saccharomyces cerevisiae have previously been shown to exhibit temperature-conditional defects in protein transport from the ER to the Golgi complex (Novick, P., S. Ferro, and R. Schekman, 1981. Cell. 25:461-469). We have found that the Sec18 and Sec23 protein functions are rapidly inactivated upon shifting mutant cells to the nonpermissive temperature (less than 1 min). This has permitted an analysis of the potential role these SEC gene products play in transport events distal to the ER. The sec-dependent transport of alpha-factor (alpha f) and carboxypeptidase Y (CPY) biosynthetic intermediates present throughout the secretory pathway was monitored in temperature shift experiments. We found that Sec18p/NSF function was required sequentially for protein transport from the ER to the Golgi complex, through multiple Golgi compartments and from the Golgi complex to the cell surface. In contrast, Sec23p function was required in the Golgi complex, but only for transport of alpha f out of an early compartment. Together, these studies define at least three functionally distinct Golgi compartments in yeast. From cis to trans these compartments contain: (a) An alpha 1----6 mannosyltransferase; (b) an alpha 1----3 mannosyltransferase; and (c) the Kex2 endopeptidase. Surprisingly, we also found that a pool of Golgi-modified CPY (p2 CPY) located in a compartment distal to the alpha 1----3 mannosyltransferase does not require Sec18p function for final delivery to the vacuole. This compartment appears to be equivalent to the Kex2 compartment as we show that a novel vacuolar CPY-alpha f-invertase fusion protein undergoes efficient Kex2-dependent cleavage resulting in the secretion of invertase. We propose that this Kex2 compartment is the site in which vacuolar proteins are sorted from proteins destined to be secreted.
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Hare, J. D. "Two-color flow-cytometric analysis of the growth cycle of Plasmodium falciparum in vitro: identification of cell cycle compartments." Journal of Histochemistry & Cytochemistry 34, no. 12 (December 1986): 1651–58. http://dx.doi.org/10.1177/34.12.2431031.
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A previous study (Hare JD, Bahler DW: J Histochem Cytochem 34:215, 1986) has shown that the flow cytometric analysis of acridine-orange-stained Plasmodium falciparum growing in vitro generates a complex two-color display, regions of which correlate with the major morphological stages. In this report, four cell cycle compartments (A-D) are defined by characteristic ratios of red and green fluorescence of cells distributed throughout the erythrocytic cycle as well as by the differential effects of several metabolic inhibitors. The primary characteristic of cells in compartment A is the significant increase in red fluorescence. Inhibition of DNA synthesis by either aphidicolin or hydroxyurea causes the accumulation of cells at the interface between compartments A and B, whereas n-butyrate prevents cells in compartment A from reaching the A-B interface. Cells in compartment A display a small increase in green fluorescence which is independent of DNA synthesis but is enhanced by n-butyrate treatment. Cells in compartment B display a continued increase in red fluorescence coupled with a significant increase in green fluorescence, reflecting the onset of DNA synthesis in compartment B. The transition to compartment C is more abrupt and is associated with a marked increase in green fluorescence and little increase in red fluorescence. Compartment D is characterized by an increase in red fluorescence and a continued rise in green fluorescence. It is postulated that these discontinuities in the two-color display reflect not only changes in the rates of RNA and DNA synthesis but also decondensation of parasite chromatin in compartment A as the organism prepares for DNA synthesis, and re-condensation in compartment D as the newly replicated chromatin prepares for segregation into merozoites. The method described promises to provide a sensitive and rapid technique to study the effects of various factors on the growth cycle of the parasite.
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Heinrich, Reinhart, and Tom A. Rapoport. "Generation of nonidentical compartments in vesicular transport systems." Journal of Cell Biology 168, no. 2 (January 17, 2005): 271–80. http://dx.doi.org/10.1083/jcb.200409087.
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How can organelles communicate by bidirectional vesicle transport and yet maintain different protein compositions? We show by mathematical modeling that a minimal system, in which the basic variables are cytosolic coats for vesicle budding and membrane-bound soluble N-ethyl-maleimide–sensitive factor attachment protein receptors (SNAREs) for vesicle fusion, is sufficient to generate stable, nonidentical compartments. A requirement for establishing and maintaining distinct compartments is that each coat preferentially packages certain SNAREs during vesicle budding. Vesicles fuse preferentially with the compartment that contains the highest concentration of cognate SNAREs, thus further increasing these SNAREs. The stable steady state is the result of a balance between this autocatalytic SNARE accumulation in a compartment and the distribution of SNAREs between compartments by vesicle budding. The resulting nonhomogeneous SNARE distribution generates coat-specific vesicle fluxes that determine the size of compartments. With nonidentical compartments established in this way, the localization and cellular transport of cargo proteins can be explained simply by their affinity for coats.
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Struhl, G., D. A. Barbash, and P. A. Lawrence. "Hedgehog acts by distinct gradient and signal relay mechanisms to organise cell type and cell polarity in the Drosophila abdomen." Development 124, no. 11 (June 1, 1997): 2155–65. http://dx.doi.org/10.1242/dev.124.11.2155.
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The epidermis of the adult Drosophila abdomen is formed by a chain of anterior (A) and posterior (P) compartments, each segment comprising one A and one P compartment. In the accompanying paper (Struhl et al., 1997), we provide evidence that Hedgehog protein (Hh), being secreted from P compartment cells, organises the pattern and polarity of A compartment cells. Here we test whether Hh acts directly or by a signal relay mechanism. We use mutations in Protein Kinase A (PKA) or smoothened (smo) to activate or to block Hh signal transduction in clones of A compartment cells. For cell type, a scalar property, both manipulations cause strictly autonomous transformations: the cells affected are exactly those and only those that are mutant. Hence, we infer that Hh acts directly on A compartment cells to specify the various types of cuticular structures that they differentiate. By contrast, these same manipulations cause non-autonomous effects on cell polarity, a vectorial property. Consequently, we surmise that Hh influences cell polarity indirectly, possibly by inducing other signalling factors. Finally, we present evidence that Hh does not polarise abdominal cells by utilising either Decapentaplegic (Dpp) or Wingless (Wg), the two morphogens through which Hh acts during limb development. We conclude that, in the abdomen, cell type and cell polarity reflect distinct outputs of Hh signalling and propose that these outputs are controlled by separable gradient and signal relay mechanisms.
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Rahmanto, Wasino Hadi, Mukhammad Asy’ari, Rame Rame, and Marihati Marihati. "Sel Elektrolisis 3–Kompartemen untuk Ekstraksi Magnesium dan Sulfat dari Sistem Larutan MgSO4–KCl–H2O." Jurnal Kimia Sains dan Aplikasi 9, no. 1 (April 1, 2006): 14–21. http://dx.doi.org/10.14710/jksa.9.1.14-21.
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Extraction of magnesium and sulfate from MgSO4–KCl–H2O solution system of 0.1 M salt concentration has been conducted. The 3–compartment electrolytic cell model was designed to fulfill the purpose. The cell is constructed from aquarium plastic box of 417 mL capacity divided into three compartments. Each compartment is separated by fixed plastic wall. One of the compartment with no electrode (mid compartment) was connected either to anodic (left) and cathodic (right) compartment using double filter paper strip of 2 x 6 (in cm) dimension. Electrolysis was performed in atmospheric environment under the 6 volt external electric potential using 7A Montana power supply. Experimental results show that electrolysis systems provide good separation of magnesium and sulfate from solution. Magnesium in the form of Mg(OH)2 and sulfate as H2SO4 has been obtained in about 92 % yield. Clear solution in the mid compartment show the absence of salt residues; both of cationic and anionic species migrate totally toward cathodic and anodic compartment respectively.
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Weill, J., and C. Reynaud. "The chicken B cell compartment." Science 238, no. 4830 (November 20, 1987): 1094–98. http://dx.doi.org/10.1126/science.3317827.
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Smalheiser, N. R. "Proteins in unexpected locations." Molecular Biology of the Cell 7, no. 7 (July 1996): 1003–14. http://dx.doi.org/10.1091/mbc.7.7.1003.
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Members of all classes of proteins--cytoskeletal components, secreted growth factors, glycolytic enzymes, kinases, transcription factors, chaperones, transmembrane proteins, and extracellular matrix proteins--have been identified in cellular compartments other than their conventional sites of action. Some of these proteins are expressed as distinct compartment-specific isoforms, have novel mechanisms for intercompartmental translocation, have distinct endogenous biological actions within each compartment, and are regulated in a compartment-specific manner as a function of physiologic state. The possibility that many, if not most, proteins have distinct roles in more than one cellular compartment has implications for the evolution of cell organization and may be important for understanding pathological conditions such as Alzheimer's disease and cancer.
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White, Michael A., and Richard G. W. Anderson. "SIGNALING NETWORKS IN LIVING CELLS." Annual Review of Pharmacology and Toxicology 45, no. 1 (September 22, 2005): 587–603. http://dx.doi.org/10.1146/annurev.pharmtox.45.120403.095807.
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Recent advances in cell signaling research suggest that multiple sets of signal transducing molecules are preorganized and sequestered in distinct compartments within the cell. These compartments are assembled and maintained by specific cellular machinery. The molecular ecology within a compartment creates an environment that favors the efficient and accurate integration of signaling information arriving from humoral, mechanical, and nutritional sources. The functional organization of these compartments suggests they are the location of signaling networks that naturally organize into hierarchical interconnected sets of molecules through their participation in different classes of interacting units. An important goal is to determine the contribution of the compartment to the function of these networks in living cells.
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Hobman, T. C., L. Woodward, and M. G. Farquhar. "The rubella virus E1 glycoprotein is arrested in a novel post-ER, pre-Golgi compartment." Journal of Cell Biology 118, no. 4 (August 15, 1992): 795–811. http://dx.doi.org/10.1083/jcb.118.4.795.
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Evidence is accumulating that a distinct compartment(s) exists in the secretory pathway interposed between the rough ER (RER) and the Golgi stack. In this study we have defined a novel post-RER, pre-Golgi compartment where unassembled subunits of rubella virus (RV) E1 glycoprotein accumulate. When RV E1 is expressed in CHO cells in the absence of E2 glycoprotein, transport of E1 to the Golgi complex is arrested. The compartment in which E1 accumulates consists of a tubular network of smooth membranes which is in continuity with the RER but has distinctive properties from either the RER, Golgi, or previously characterized intermediate compartments. It lacks RER and Golgi membrane proteins and is not disrupted by agents which disrupt either the RER (thapsigargin, ionomycin) or Golgi (nocodazole and brefeldin A). However, luminal ER proteins bearing the KDEL signal have access to this compartment. Kinetically the site of E1 arrest lies distal to or at the site where palmitylation occurs and proximal to the low temperature 15 degrees C block. Taken together the findings suggest that the site of E1 arrest corresponds to, or is located close to the exit site from the ER. This compartment could be identified morphologically because it is highly amplified in cells overexpressing unassembled E1 subunits, but it may have its counterpart among the transitional elements of non-transfected cells. We conclude that the site of E1 arrest may represent a new compartment or a differentiated proximal moiety of the intermediate compartment.
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Griffiths, G., M. Ericsson, J. Krijnse-Locker, T. Nilsson, B. Goud, H. D. Söling, B. L. Tang, S. H. Wong, and W. Hong. "Localization of the Lys, Asp, Glu, Leu tetrapeptide receptor to the Golgi complex and the intermediate compartment in mammalian cells." Journal of Cell Biology 127, no. 6 (December 15, 1994): 1557–74. http://dx.doi.org/10.1083/jcb.127.6.1557.
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The carboxyl-terminal Lys-Asp-Glu-Leu (KDEL), or a closely-related sequence, is important for ER localization of both lumenal as well as type II membrane proteins. This sequence functions as a retrieval signal at post-ER compartment(s), but the exact compartment(s) where the retrieval occurs remains unresolved. With an affinity-purified antibody against the carboxyl-terminal sequence of the mammalian KDEL receptor, we have investigated its subcellular localization using immunogold labeling on thawed cryosections of different tissues, such as mouse spermatids and rat pancreas, as well as HeLa, Vero, NRK, and mouse L cells. We show that rab1 is an excellent marker of the intermediate compartment, and we use this marker, as well as budding profiles of the mouse hepatitis virus (MHV) in cells infected with this virus, to identify this compartment. Our results demonstrate that the KDEL receptor is concentrated in the intermediate compartment, as well as in the Golgi stack. Lower but significant labeling was detected in the rough ER. In general, only small amounts of the receptor were detected on the trans side of the Golgi stack, including the trans-Golgi network (TGN) of normal cells and tissues. However, some stress conditions, such as infection with vaccinia virus or vesicular stomatitis virus, as well as 20 degrees C or 43 degrees C treatment, resulted in a significant shift of the distribution towards the trans-TGN side of the Golgi stack. This shift could be quantified in HeLa cells stably expressing a TGN marker. No significant labeling was detected in structures distal to the TGN under all conditions tested. After GTP gamma S treatment of permeabilized cells, the receptor was detected in the beta-COP-containing buds/vesicles that accumulate after this treatment, suggesting that these vesicles may transport the receptor between compartments. We propose that retrieval of KDEL-containing proteins occurs at multiple post-ER compartments up to the TGN along the exocytotic pathway, and that within this pathway, the amounts of the receptor in different compartments varies according to physiological conditions.
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Strick, David J., and Lisa A. Elferink. "Rab15 Effector Protein: A Novel Protein for Receptor Recycling from the Endocytic Recycling Compartment." Molecular Biology of the Cell 16, no. 12 (December 2005): 5699–709. http://dx.doi.org/10.1091/mbc.e05-03-0204.
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Sorting endosomes and the endocytic recycling compartment are critical intracellular stores for the rapid recycling of internalized membrane receptors to the cell surface in multiple cell types. However, the molecular mechanisms distinguishing fast receptor recycling from sorting endosomes and slow receptor recycling from the endocytic recycling compartment remain poorly understood. We previously reported that Rab15 differentially regulates transferrin receptor trafficking through sorting endosomes and the endocytic recycling compartment, suggesting a role for distinct Rab15-effector interactions at these endocytic compartments. In this study, we identified the novel protein Rab15 effector protein (REP15) as a binding partner for Rab15-GTP. REP15 is compartment specific, colocalizing with Rab15 and Rab11 on the endocytic recycling compartment but not with Rab15, Rab4, or early endosome antigen 1 on sorting endosomes. REP15 interacts directly with Rab15-GTP but not with Rab5 or Rab11. Consistent with its localization, REP15 overexpression and small interfering RNA-mediated depletion inhibited transferrin receptor recycling from the endocytic recycling compartment, without affecting receptor entry into or recycling from sorting endosomes. Our data identify REP15 as a compartment-specific protein for receptor recycling from the endocytic recycling compartment, highlighting that the rapid and slow modes of transferrin receptor recycling are mechanistically distinct pathways.
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Brickman, M. J., J. M. Cook, and A. E. Balber. "Low temperature reversibly inhibits transport from tubular endosomes to a perinuclear, acidic compartment in African trypanosomes." Journal of Cell Science 108, no. 11 (November 1, 1995): 3611–21. http://dx.doi.org/10.1242/jcs.108.11.3611.
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We have used electron microscopy and flow cytofluorimetry to study endocytosis and intracellular transport of fluid phase bovine serum albumen gold complexes and membrane bound concanavalin A through endosomal compartments of bloodstream forms of Trypanosoma brucei rhodesiense. Both markers were rapidly endocytosed from the flagellar pocket. Within 20 minutes at 37 degrees C the markers reached a large, vesicular, perinuclear compartment that stained heavily with the CB1 monoclonal antibody. Neither marker left the flagellar pocket and entered cells at 4 degrees C. When cells were incubated at 12 degrees C, both markers entered the cell and were transported to collecting tubules, a tubular endosomal compartment that receives endocytosed material from coated endocytic vesicles. However, no material was transported from collecting tubules to the late, perinuclear compartment at 12 degrees C. The morphology of collecting tubule membranes was specifically altered at 12 degrees C; tubules became shorter and were arrayed near the flagellar pocket. The morphological alteration and the block in transport of endocytic markers to the perinuclear compartment seen at 12 degrees C were reversed 10 minutes after cells were returned to 37 degrees C. We also used flow cytofluorimetric measurements of pH dependent fluorescence quenching to measure the pH of the terminal endocytic compartment. Fluoresceinated lectins accumulated in a terminal compartment with a pH of 6.0-6.1, a value considerably higher than that of mammalian lysosomes. Fluorescence from fluoresceinated lectins in this terminal endocytic compartment was dequenched when bloodstream forms were incubated in the presence of chloroquine.
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Heasley, Lydia R., Steven M. Markus, and Jennifer G. DeLuca. "“Wait anaphase” signals are not confined to the mitotic spindle." Molecular Biology of the Cell 28, no. 9 (May 2017): 1186–94. http://dx.doi.org/10.1091/mbc.e17-01-0036.
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The spindle assembly checkpoint ensures the faithful inheritance of chromosomes by arresting mitotic progression in the presence of kinetochores that are not attached to spindle microtubules. This is achieved through inhibition of the anaphase-promoting complex/cyclosome by a kinetochore-derived “wait anaphase” signal known as the mitotic checkpoint complex. It remains unclear whether the localization and activity of these inhibitory complexes are restricted to the mitotic spindle compartment or are diffusible throughout the cytoplasm. Here we report that “wait anaphase” signals are indeed able to diffuse outside the confines of the mitotic spindle compartment. Using a cell fusion approach to generate multinucleate cells, we investigate the effects of checkpoint signals derived from one spindle compartment on a neighboring spindle compartment. We find that spindle compartments in close proximity wait for one another to align all chromosomes before entering anaphase synchronously. Synchrony is disrupted in cells with increased interspindle distances and cellular constrictions between spindle compartments. In addition, when mitotic cells are fused with interphase cells, “wait anaphase” signals are diluted, resulting in premature mitotic exit. Overall our studies reveal that anaphase inhibitors are diffusible and active outside the confines of the mitotic spindle from which they are derived.
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Smith, Jennifer L., Christie M. McBride, Parvathi S. Nataraj, Daniel C. Bartos, Craig T. January, and Brian P. Delisle. "Trafficking-deficient hERG K+ channels linked to long QT syndrome are regulated by a microtubule-dependent quality control compartment in the ER." American Journal of Physiology-Cell Physiology 301, no. 1 (July 2011): C75—C85. http://dx.doi.org/10.1152/ajpcell.00494.2010.
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The human ether-a-go-go related gene ( hERG) encodes the voltage-gated K+ channel that underlies the rapidly activating delayed-rectifier current in cardiac myocytes. hERG is synthesized in the endoplasmic reticulum (ER) as an “immature” N-linked glycoprotein and is terminally glycosylated in the Golgi apparatus. Most hERG missense mutations linked to long QT syndrome type 2 (LQT2) reduce the terminal glycosylation and functional expression. We tested the hypothesis that a distinct pre-Golgi compartment negatively regulates the trafficking of some LQT2 mutations to the Golgi apparatus. We found that treating cells in nocodazole, a microtubule depolymerizing agent, altered the subcellular localization, functional expression, and glycosylation of the LQT2 mutation G601S-hERG differently from wild-type hERG (WT-hERG). G601S-hERG quickly redistributed to peripheral compartments that partially colocalized with KDEL (Lys-Asp-Glu-Leu) chaperones but not calnexin, Sec31, or the ER golgi intermediate compartment (ERGIC). Treating cells in E-4031, a drug that increases the functional expression of G601S-hERG, prevented the accumulation of G601S-hERG to the peripheral compartments and increased G601S-hERG colocalization with the ERGIC. Coexpressing the temperature-sensitive mutant G protein from vesicular stomatitis virus, a mutant N-linked glycoprotein that is retained in the ER, showed it was not restricted to the same peripheral compartments as G601S-hERG at nonpermissive temperatures. We conclude that the trafficking of G601S-hERG is negatively regulated by a microtubule-dependent compartment within the ER. Identifying mechanisms that prevent the sorting or promote the release of LQT2 channels from this compartment may represent a novel therapeutic strategy for LQT2.
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Sigal, S. H., S. Brill, A. S. Fiorino, and L. M. Reid. "The liver as a stem cell and lineage system." American Journal of Physiology-Gastrointestinal and Liver Physiology 263, no. 2 (August 1, 1992): G139—G148. http://dx.doi.org/10.1152/ajpgi.1992.263.2.g139.
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We propose that the liver is a stem cell and lineage system with many parallels to lineages in the bone marrow, gut, and epidermis, varying from them only in kinetics. All are organized with three compartments: a slow cycling stem cell compartment with cells expressing a fetal phenotype and responding slowly to injury; an amplification compartment with cells of intermediate phenotype rapidly proliferating in response to regenerative stimuli or acute injuries; and a terminal differentiation compartment in which cells increasingly differentiate and gradually lose their ability to divide. In all systems, both those with slow or rapid kinetics, the various compartments are positioned in a polarized organization, are associated with a gradient in the chemistry of the extracellular matrix, and show lineage-position-dependent growth responses, gene expression, pharmacological and toxicological responses, and reaction to viruses and radiation. In general, known oncogens selectively kill cells in the differentiation compartment inducing chronic regenerative responses of the cells in stem cell and/or amplification compartment. Tumors arise by subsequent transformation of the activated stem cells or early precursor cells. The evidence for a lineage model consists of the data implicating gradients in cell size, ploidy, growth potential, and antigenic and gene expression in the liver parenchyma along the sinusoidal plates. The traditional explanation for this heterogeneity is that it represents adaption of cells to a changing sinusoidal microenvironment dictated by the direction of blood flow. However, we review the extant data and suggest that it more readily supports a lineage model involving a maturation process beginning with stem cells and precursors in the periportal zone and ending with sensescing parenchyma near the central vein. Support for this theory is provided by the studies on phenotypic heterogeneity in liver, investigations into the embryology of the liver, and analyses of the responses of liver to chemical and viral oncogens that induce rapid proliferation of small cells with oval-shaped nuclei, "oval cells," now thought to be closely related to liver stem cells. The lineage model provides clarity and insights into many aspects of liver biology and disease including the limited proliferative ability of in vitro parenchymal cultures, liver regeneration, gene expression, viral infection, hepatocellular carcinogenesis, liver cell transplantation, and aging.
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Bogan, Jonathan S., and Harvey F. Lodish. "Two Compartments for Insulin-Stimulated Exocytosis in 3t3-L1 Adipocytes Defined by Endogenous Acrp30 and Glut4." Journal of Cell Biology 146, no. 3 (August 9, 1999): 609–20. http://dx.doi.org/10.1083/jcb.146.3.609.
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Insulin stimulates adipose cells both to secrete proteins and to translocate the GLUT4 glucose transporter from an intracellular compartment to the plasma membrane. We demonstrate that whereas insulin stimulation of 3T3-L1 adipocytes has no effect on secretion of the α3 chain of type VI collagen, secretion of the protein hormone adipocyte complement related protein of 30 kD (ACRP30) is markedly enhanced. Like GLUT4, regulated exocytosis of ACRP30 appears to require phosphatidylinositol-3-kinase activity, since insulin-stimulated ACRP30 secretion is blocked by pharmacologic inhibitors of this enzyme. Thus, 3T3-L1 adipocytes possess a regulated secretory compartment containing ACRP30. Whether GLUT4 recycles to such a compartment has been controversial. We present deconvolution immunofluorescence microscopy data demonstrating that the subcellular distributions of ACRP30 and GLUT4 are distinct and nonoverlapping; in contrast, those of GLUT4 and the transferrin receptor overlap. Together with supporting evidence that GLUT4 does not recycle to a secretory compartment via the trans-Golgi network, we conclude that there are at least two compartments that undergo insulin-stimulated exocytosis in 3T3-L1 adipocytes: one for ACRP30 secretion and one for GLUT4 translocation.
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Yovchev, Mladen I., Jialin Zhang, David S. Neufeld, Petar N. Grozdanov, and Mariana D. Dabeva. "Thymus cell antigen-1-expressing cells in the oval cell compartment." Hepatology 50, no. 2 (April 6, 2009): 601–11. http://dx.doi.org/10.1002/hep.23012.
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Low, Seng Hui, Masumi Miura, Paul A. Roche, Anita C. Valdez, Keith E. Mostov, and Thomas Weimbs. "Intracellular Redirection of Plasma Membrane Trafficking after Loss of Epithelial Cell Polarity." Molecular Biology of the Cell 11, no. 9 (September 2000): 3045–60. http://dx.doi.org/10.1091/mbc.11.9.3045.
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In polarized Madin-Darby canine kidney epithelial cells, components of the plasma membrane fusion machinery, the t-SNAREs syntaxin 2, 3, and 4 and SNAP-23, are differentially localized at the apical and/or basolateral plasma membrane domains. Here we identify syntaxin 11 as a novel apical and basolateral plasma membrane t-SNARE. Surprisingly, all of these t-SNAREs redistribute to intracellular locations when Madin-Darby canine kidney cells lose their cellular polarity. Apical SNAREs relocalize to the previously characterized vacuolar apical compartment, whereas basolateral SNAREs redistribute to a novel organelle that appears to be the basolateral equivalent of the vacuolar apical compartment. Both intracellular plasma membrane compartments have an associated prominent actin cytoskeleton and receive membrane traffic from cognate apical or basolateral pathways, respectively. These findings demonstrate a fundamental shift in plasma membrane traffic toward intracellular compartments while protein sorting is preserved when epithelial cells lose their cell polarity.
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Baron, R., L. Neff, D. Louvard, and P. J. Courtoy. "Cell-mediated extracellular acidification and bone resorption: evidence for a low pH in resorbing lacunae and localization of a 100-kD lysosomal membrane protein at the osteoclast ruffled border." Journal of Cell Biology 101, no. 6 (December 1, 1985): 2210–22. http://dx.doi.org/10.1083/jcb.101.6.2210.
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The extracellular compartment where bone resorption occurs, between the osteoclast and bone matrix, is shown in this report to be actively acidified. The weak base acridine orange accumulates within this compartment but dissipates after incubation with ammonium chloride. Upon removal of ammonium chloride, the cells are able to rapidly reacidify this compartment. The highly convoluted plasma membrane of the osteoclast facing this acidic compartment (ruffled border) is shown to contain a 100-kD integral membrane protein otherwise present in limiting membranes of lysosomes and other related acidified organelles (Reggio, H., D. Bainton, E. Harms, E. Coudrier, and D. Louvard, 1984, J. Cell Biol., 99:1511-1526; Tougard, C., D. Louvard, R. Picart, and A. Tixier-Vidal, 1985, J. Cell Biol. 100:786-793). Antibodies recognizing this 100-kD lysosomal membrane protein cross-react with a proton-pump ATPase from pig gastric mucosae (Reggio, H., D. Bainton, E. Harms, E. Coudrier, and D. Louvard, 1984, J. Cell Biol., 99:1511-1526), therefore raising the possibility that it plays a role in the acidification of both intracellular organelles and extracellular compartments. Lysosomal enzymes are also directionally secreted by the osteoclast into the acidified extracellular compartment which can therefore be considered as the functional equivalent of a secondary lysosome with a low pH, acid hydrolases, the substrate, and a limiting membrane containing the 100-kD antigen.
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Salas-Lucia, Federico, Barbara M. L. C. Bocco, Kristof Rada, Csaba Fekete, Balazs Gereben, and Antonio C. Bianco. "T3 Enters Axon Terminals of Mouse Cortical Neurons, Is Retrogradely Transported to the Cell Nucleus and Activates Gene Expression." Journal of the Endocrine Society 5, Supplement_1 (May 1, 2021): A978. http://dx.doi.org/10.1210/jendso/bvab048.2000.
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Abstract Thyroid hormone (TH) is critical for brain development and function. T3 enters neurons through membrane transporters and reaches the cell nucleus where it binds to receptors (TR) to regulate gene transcription. However, neurons also express the type 3 deiodinase (D3), which is located in the cellular and nuclear membranes and inactivates T3. Here, we investigated the fate and biological impact of T3 that enters neurons through axons. Primary cortical neurons were isolated from E16.5 embryos of the TH action indicator (THAI) mice, which were engineered with a TH-responsive transgene where three copies of a T3-responsive element drive a luciferase (Luc) reporter. Neurons were seeded on a microfluidic device consisting of two independent compartments: (i) cellular, where about 70-90,000 cell bodies were located, and (ii) axonal, where a few hundred distal axons were located. Fluidic isolation of the compartments was monitored with Alexa Fluor 594 hydrazide. In the first set of experiments (repeated 3 times), 8-10-day old cultures were incubated for 48h with medium containing 1% charcoal-stripped serum (Tx-medium). Subsequently, 10nM T3 was added to the axonal compartment, and 24h later cell bodies were harvested and Luc mRNA measured by RT-qPCR. There was a 2.4 ± 0.7-fold increase in Luc mRNA levels, but the addition of 2uM Silychristin (MCT8 inhibitor) to the axonal compartment reduced T3 induction of Luc mRNA by 32 ± 4.2%. In the second set of experiments (repeated 3 times), 4.9 ± 2.2pM 125I-T3 (final concentration) was added to the cellular or axonal compartments. Medium was sampled and 125I-T3 and its metabolites were separated/quantified via UPLC linked to a flow scintillation detector. After 72h of adding 125I-T3 to the axonal compartment, about 0.73 % 125I-T3 (0.052 ± 0.025pM) was found in the cellular compartment. In addition, 3,3’-125I-T2 and 125I (0.011 ± 0.003 and 0.052 ± 0.023pM, respectively) were also detected. When 125I-T3 was added to the cellular compartment, about 1.6% 125I-T3 (0.048 ± 0.027pM), no metabolites, was detected in the axonal compartment. Only background radioactivity was detected in the opposing compartment when 125I-T3 was added in the absence of cells. We conclude that T3 can be taken up by neuronal axons, partly via MCT8, and transported retrogradely to the cell nucleus to initiate TH signaling. D3-generated T3 metabolites exit the cell body alongside with small amounts of intact T3. This pathway could explain how D2-generated T3 in tanycytes is taken up by TRH-secreting neurons to mediate negative T3 feedback. Anterograde T3 transport was also detected, the significance of which remains unknown.
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Struhl, G., D. A. Barbash, and P. A. Lawrence. "Hedgehog organises the pattern and polarity of epidermal cells in the Drosophila abdomen." Development 124, no. 11 (June 1, 1997): 2143–54. http://dx.doi.org/10.1242/dev.124.11.2143.
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The abdomen of adult Drosophila, like that of other insects, is formed by a continuous epithelium spanning several segments. Each segment is subdivided into an anterior (A) and posterior (P) compartment, distinguished by activity of the selector gene engrailed (en) in P but not A compartment cells. Here we provide evidence that Hedgehog (Hh), a protein secreted by P compartment cells, spreads into each A compartment across the anterior and the posterior boundaries to form opposing concentration gradients that organize cell pattern and polarity. We find that anteriorly and posteriorly situated cells within the A compartment respond in distinct ways to Hh: they express different combinations of genes and form different cell types. They also form polarised structures that, in the anterior part, point down the Hh gradient and, in the posterior part, point up the gradient - therefore all structures point posteriorly. Finally, we show that ectopic Hh can induce cells in the middle of each A compartment to activate en. Where this happens, A compartment cells are transformed into an ectopic P compartment and reorganise pattern and polarity both within and around the transformed tissue. Many of these results are unexpected and lead us to reassess the role of gradients and compartments in patterning insect segments.
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Milán, Marco, Ulrich Weihe, Stanley Tiong, Welcome Bender, and Stephen M. Cohen. "msh specifies dorsal cell fate in the Drosophila wing." Development 128, no. 17 (September 1, 2001): 3263–68. http://dx.doi.org/10.1242/dev.128.17.3263.
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Drosophila limbs develop from imaginal discs that are subdivided into compartments. Dorsal-ventral subdivision of the wing imaginal disc depends on apterous activity in dorsal cells. Apterous protein is expressed in dorsal cells and is responsible for (1) induction of a signaling center along the dorsal-ventral compartment boundary (2) establishment of a lineage restriction boundary between compartments and (3) specification of dorsal cell fate. Here, we report that the homeobox gene msh (muscle segment homeobox) acts downstream of apterous to confer dorsal identity in wing development.
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Kaeser, Pascal S., Michael A. Klein, Petra Schwarz, and Adriano Aguzzi. "Efficient Lymphoreticular Prion Propagation Requires PrPc in Stromal and Hematopoietic Cells." Journal of Virology 75, no. 15 (August 1, 2001): 7097–106. http://dx.doi.org/10.1128/jvi.75.15.7097-7106.2001.
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ABSTRACT In most prion diseases, infectivity accumulates in lymphoreticular organs early after infection. Defects in hematopoietic compartments, such as impaired B-cell maturation, or in stromal compartments, such as abrogation of follicular dendritic cells, can delay or prevent lymphoreticular prion colonization. However, the nature of the compartment in which prion replication takes place is controversial, and it is unclear whether this compartment coincides with that expressing the normal prion protein (PrPc). Here we studied the distribution of infectivity in splenic fractions of wild-type and fetal liver chimeric mice carrying the gene that encodes PrPc (Prnp) solely on hematopoietic or on stromal cells. We fractionated spleens at various times after intraperitoneal challenge with prions and assayed infectivity by bioassay. Upon high-dose challenge, chimeras carrying PrPcon hematopoietic cells accumulated prions in stroma and in purified splenocytes. In contrast, after low-dose challenge ablation ofPrnp in either compartment prevented splenic accumulation of infectivity, indicating that optimal prion replication requires PrPc expression by both stromal and hematopoietic compartments.
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Han, Z., and R. A. Firtel. "The homeobox-containing gene Wariai regulates anterior-posterior patterning and cell-type homeostasis in Dictyostelium." Development 125, no. 2 (January 15, 1998): 313–25. http://dx.doi.org/10.1242/dev.125.2.313.
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We have identified a Dictyostelium gene, Wariai (Wri), that encodes a protein with a homeobox and seven ankyrin repeats; both domains are required for function. A null mutation results in a more than doubling of the size of the prestalk O (pstO) compartment, one of the anterior prestalk compartments lying along the anterior-posterior axis of the migrating slug. There is a concomitant decrease in the more posterior prespore domain and no change in the more anterior prestalk A (pstA) and prestalk AB (pstAB) domains. wri null cells also have a morphological defect consistent with an increase in the pstO cell population. Wri itself is preferentially expressed in the pstA but not the pstO compartment, raising the possibility that Wri regulation of pstO compartment size is nonautonomous. Analysis of chimeric organisms is consistent with this model. Development in Dictyostelium is highly regulative, with cells within the prestalk and prespore populations being able to transdifferentiate into other cells to maintain proper cell-type proportioning. Our results suggest that Wri controls cell-type proportioning, possibly by functioning as a negative regulator of a pathway mediating pstO cell differentiation and controlling the mechanism of homeostasis regulating the size of one or more of the cell-type compartments. Our results also suggest that homeobox gene regulation of anterior-posterior axis patterning may have evolved prior to the evolution of metazoans.
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IGAWA, Manabu, Hitomi HIRAGA, and Takaaki NAKAMURA. "Neutralization Dialysis by Three-Compartment Cell." Journal of Ion Exchange 14, Supplement (2003): 249–52. http://dx.doi.org/10.5182/jaie.14.supplement_249.
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He, Xin, Lei Wang, Jizhou Yan, Chaoxing Yuan, Eric S. Witze, and Xianxin Hua. "Menin localization in cell membrane compartment." Cancer Biology & Therapy 17, no. 1 (November 11, 2015): 114–22. http://dx.doi.org/10.1080/15384047.2015.1108497.
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Tonge, Peter D., Victor Olariu, Daniel Coca, Visakan Kadirkamanathan, Kelly E. Burrell, Stephen A. Billings, and Peter W. Andrews. "Prepatterning in the Stem Cell Compartment." PLoS ONE 5, no. 5 (May 28, 2010): e10901. http://dx.doi.org/10.1371/journal.pone.0010901.
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Geiger, Hartmut, Gerald de Haan, and M. Carolina Florian. "The ageing haematopoietic stem cell compartment." Nature Reviews Immunology 13, no. 5 (April 15, 2013): 376–89. http://dx.doi.org/10.1038/nri3433.
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Patel, Brijesh V., Kate C. Tatham, Michael R. Wilson, Kieran P. O'Dea, and Masao Takata. "In vivo compartmental analysis of leukocytes in mouse lungs." American Journal of Physiology-Lung Cellular and Molecular Physiology 309, no. 7 (October 1, 2015): L639—L652. http://dx.doi.org/10.1152/ajplung.00140.2015.
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The lung has a unique structure consisting of three functionally different compartments (alveolar, interstitial, and vascular) situated in an extreme proximity. Current methods to localize lung leukocytes using bronchoalveolar lavage and/or lung perfusion have significant limitations for determination of location and phenotype of leukocytes. Here we present a novel method using in vivo antibody labeling to enable accurate compartmental localization/quantification and phenotyping of mouse lung leukocytes. Anesthetized C57BL/6 mice received combined in vivo intravenous and intratracheal labeling with fluorophore-conjugated anti-CD45 antibodies, and lung single-cell suspensions were analyzed by flow cytometry. The combined in vivo intravenous and intratracheal CD45 labeling enabled robust separation of the alveolar, interstitial, and vascular compartments of the lung. In naive mice, the alveolar compartment consisted predominantly of resident alveolar macrophages. The interstitial compartment, gated by events negative for both intratracheal and intravenous CD45 staining, showed two conventional dendritic cell populations, as well as a Ly6Clo monocyte population. Expression levels of MHCII on these interstitial monocytes were much higher than on the vascular Ly6Clo monocyte populations. In mice exposed to acid aspiration-induced lung injury, this protocol also clearly distinguished the three lung compartments showing the dynamic trafficking of neutrophils and exudative monocytes across the lung compartments during inflammation and resolution. This simple in vivo dual-labeling technique substantially increases the accuracy and depth of lung flow cytometric analysis, facilitates a more comprehensive examination of lung leukocyte pools, and enables the investigation of previously poorly defined “interstitial” leukocyte populations during models of inflammatory lung diseases.
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Kobayashi, T., and J. M. Robinson. "A novel intracellular compartment with unusual secretory properties in human neutrophils." Journal of Cell Biology 113, no. 4 (May 15, 1991): 743–56. http://dx.doi.org/10.1083/jcb.113.4.743.
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Human neutrophils contain a novel intracellular compartment that is distinct from the previously characterized azurophil and specific granules. This compartment is distinguished by the presence of cytochemically detectable alkaline phosphatase activity. The alkaline phosphatase-containing compartments are short rod-shaped organelles that rapidly undergo a dramatic reorganization upon cell stimulation with either a chemoattractant or an active phorbol ester. Biochemical analysis shows that in unstimulated neutrophils the majority of the alkaline phosphatase activity is intracellular, but after stimulation essentially all of this activity becomes associated with the cell surface. The exocytotic pathway is unusual in that these small organelles fuse to form elongated tubular structures before their association with the plasmalemma.
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Haka, Abigail S., Inna Grosheva, Ethan Chiang, Adina R. Buxbaum, Barbara A. Baird, Lynda M. Pierini, and Frederick R. Maxfield. "Macrophages Create an Acidic Extracellular Hydrolytic Compartment to Digest Aggregated Lipoproteins." Molecular Biology of the Cell 20, no. 23 (December 2009): 4932–40. http://dx.doi.org/10.1091/mbc.e09-07-0559.
Full textAbstract:
A critical event in atherogenesis is the interaction of macrophages with subendothelial lipoproteins. Although most studies model this interaction by incubating macrophages with monomeric lipoproteins, macrophages in vivo encounter lipoproteins that are aggregated. The physical features of the lipoproteins require distinctive mechanisms for their uptake. We show that macrophages create an extracellular, acidic, hydrolytic compartment to carry out digestion of aggregated low-density lipoproteins. We demonstrate delivery of lysosomal contents to these specialized compartments and their acidification by vacuolar ATPase, enabling aggregate catabolism by lysosomal acid hydrolases. We observe transient sealing of portions of the compartments, allowing formation of an “extracellular” proton gradient. An increase in free cholesterol is observed in aggregates contained in these compartments. Thus, cholesteryl ester hydrolysis can occur extracellularly in a specialized compartment, a lysosomal synapse, during the interaction of macrophages with aggregated low-density lipoprotein. A detailed understanding of these processes is essential for developing strategies to prevent atherosclerosis.
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Griffiths, G., R. Matteoni, R. Back, and B. Hoflack. "Characterization of the cation-independent mannose 6-phosphate receptor-enriched prelysosomal compartment in NRK cells." Journal of Cell Science 95, no. 3 (March 1, 1990): 441–61. http://dx.doi.org/10.1242/jcs.95.3.441.
Full textAbstract:
The structure of a late endosomal compartment, which contains the bulk of the cation-independent mannose 6-phosphate receptor (MPR) in NRK cells, is documented using immunocytochemistry and cryo-sections, as well as conventional Epon sections. This compartment, which we refer to as the prelysosomal compartment (PLC), has a complex three-dimensional structure consisting of tubuloreticular domains in continuity with vesicular parts. The latter are characterized by a high density of internal membranes, which may be either tubular or sheet-like, that label extensively for the MPR. This structural organization was also maintained after fractionation in sucrose gradients. The amount of MPR immunolabelling was then quantitated with respect to the membrane surface areas of the four compartments where it is found: namely, the plasma membrane, early endosomes, the trans Golgi network and the PLC. The results showed that in NRK cells 90% of the labelling for the receptor was found in the PLC, with the rest distributed over the other three compartments. Cytochemical studies indicated that the PLC is the first structure along the endocytic pathway that gives a significant reaction for acid phosphatase. However, the PLC is clearly distinct from the MPR-negative lysosomes, which are also acid phosphatase-positive, since the two organelles could be physically separated from each other after fractionation on Percoll gradients.
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Zecca, M., K. Basler, and G. Struhl. "Sequential organizing activities of engrailed, hedgehog and decapentaplegic in the Drosophila wing." Development 121, no. 8 (August 1, 1995): 2265–78. http://dx.doi.org/10.1242/dev.121.8.2265.
Full textAbstract:
The Drosophila wing is formed by two cell populations, the anterior and posterior compartments, which are distinguished by the activity of the selector gene engrailed (en) in posterior cells. Here, we show that en governs growth and patterning in both compartments by controlling the expression of the secreted proteins hedgehog (hh) and decapentaplegic (dpp) as well as the response of cells to these signaling molecules. First, we demonstrate that en activity programs wing cells to express hh whereas the absence of en activity programs them to respond to hh by expressing dpp. As a consequence, posterior cells secrete hh and induce a stripe of neighboring anterior cells across the compartment boundary to secrete dpp. Second, we demonstrate that dpp can exert a long-range organizing influence on surrounding wing tissue, specifying anterior or posterior pattern depending on the compartmental provenance, and hence the state of en activity, of the responding cells. Thus, dpp secreted by anterior cells along the compartment boundary has the capacity to organize the development of both compartments. Finally, we report evidence suggesting that dpp may exert its organizing influence by acting as a gradient morphogen in contrast to hh which appears to act principally as a short range inducer of dpp.
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Borum, P. R. "Plasma carnitine compartment and red blood cell carnitine compartment of healthy adults." American Journal of Clinical Nutrition 46, no. 3 (September 1, 1987): 437–41. http://dx.doi.org/10.1093/ajcn/46.3.437.
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tom Dieck, Susanne, Wilko D. Altrock, Michael M. Kessels, Britta Qualmann, Hanna Regus, Dana Brauner, Anna Fejtová, Oliver Bracko, Eckart D. Gundelfinger, and Johann H. Brandstätter. "Molecular dissection of the photoreceptor ribbon synapse." Journal of Cell Biology 168, no. 5 (February 22, 2005): 825–36. http://dx.doi.org/10.1083/jcb.200408157.
Full textAbstract:
The ribbon complex of retinal photoreceptor synapses represents a specialization of the cytomatrix at the active zone (CAZ) present at conventional synapses. In mice deficient for the CAZ protein Bassoon, ribbons are not anchored to the presynaptic membrane but float freely in the cytoplasm. Exploiting this phenotype, we dissected the molecular structure of the photoreceptor ribbon complex. Identifiable CAZ proteins segregate into two compartments at the ribbon: a ribbon-associated compartment including Piccolo, RIBEYE, CtBP1/BARS, RIM1, and the motor protein KIF3A, and an active zone compartment including RIM2, Munc13-1, a Ca2+ channel α1 subunit, and ERC2/CAST1. A direct interaction between the ribbon-specific protein RIBEYE and Bassoon seems to link the two compartments and is responsible for the physical integrity of the photoreceptor ribbon complex. Finally, we found the RIBEYE homologue CtBP1 at ribbon and conventional synapses, suggesting a novel role for the CtBP/BARS family in the molecular assembly and function of central nervous system synapses.