Relevant bibliographies by topics / Organell

Contents

  1. Journal articles
  2. Dissertations / Theses
  3. Books
  4. Book chapters
  5. Conference papers
  6. Reports

Academic literature on the topic 'Organell'

Author: Grafiati
Published: 4 June 2021
Last updated: 3 March 2023

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Organell.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Journal articles on the topic "Organell"

1

Wagner, Nicolai, Milena Stephan, Doris Höglinger, and André Nadler. "Der Click‐Cage: Organell‐spezifische Photoaktivierung von Lipid‐Botenstoffen." Angewandte Chemie 130, no. 40 (September 3, 2018): 13523–27. http://dx.doi.org/10.1002/ange.201807497.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Oborník, Miroslav. "Organellar Evolution: A Path from Benefit to Dependence." Microorganisms 10, no. 1 (January 7, 2022): 122. http://dx.doi.org/10.3390/microorganisms10010122.

Full text
Abstract:
Eukaryotic organelles supposedly evolved from their bacterial ancestors because of their benefits to host cells. However, organelles are quite often retained, even when the beneficial metabolic pathway is lost, due to something other than the original beneficial function. The organellar function essential for cell survival is, in the end, the result of organellar evolution, particularly losses of redundant metabolic pathways present in both the host and endosymbiont, followed by a gradual distribution of metabolic functions between the organelle and host. Such biological division of metabolic labor leads to mutual dependence of the endosymbiont and host. Changing environmental conditions, such as the gradual shift of an organism from aerobic to anaerobic conditions or light to dark, can make the original benefit useless. Therefore, it can be challenging to deduce the original beneficial function, if there is any, underlying organellar acquisition. However, it is also possible that the organelle is retained because it simply resists being eliminated or digested untill it becomes indispensable.
APA, Harvard, Vancouver, ISO, and other styles
3

Mallo, Natalia, Justin Fellows, Carla Johnson, and Lilach Sheiner. "Protein Import into the Endosymbiotic Organelles of Apicomplexan Parasites." Genes 9, no. 8 (August 14, 2018): 412. http://dx.doi.org/10.3390/genes9080412.

Full text
Abstract:
: The organelles of endosymbiotic origin, plastids, and mitochondria, evolved through the serial acquisition of endosymbionts by a host cell. These events were accompanied by gene transfer from the symbionts to the host, resulting in most of the organellar proteins being encoded in the cell nuclear genome and trafficked into the organelle via a series of translocation complexes. Much of what is known about organelle protein translocation mechanisms is based on studies performed in common model organisms; e.g., yeast and humans or Arabidopsis. However, studies performed in divergent organisms are gradually accumulating. These studies provide insights into universally conserved traits, while discovering traits that are specific to organisms or clades. Apicomplexan parasites feature two organelles of endosymbiotic origin: a secondary plastid named the apicoplast and a mitochondrion. In the context of the diseases caused by apicomplexan parasites, the essential roles and divergent features of both organelles make them prime targets for drug discovery. This potential and the amenability of the apicomplexan Toxoplasma gondii to genetic manipulation motivated research about the mechanisms controlling both organelles’ biogenesis. Here we provide an overview of what is known about apicomplexan organelle protein import. We focus on work done mainly in T. gondii and provide a comparison to model organisms.
APA, Harvard, Vancouver, ISO, and other styles
4

Evans, David E., and Chris Hawes. "Organelle Biogenesis and Positioning in Plants." Biochemical Society Transactions 38, no. 3 (May 24, 2010): 729–32. http://dx.doi.org/10.1042/bst0380729.

Full text
Abstract:
The biogenesis and positioning of organelles involves complex interacting processes and precise control. Progress in our understanding is being made rapidly as advances in analysing the nuclear and organellar genome and proteome combine with developments in live-cell microscopy and manipulation at the subcellular level. This paper introduces the collected papers resulting from Organelle Biogenesis and Positioning in Plants, the 2009 Biochemical Society Annual Symposium. Including papers on the nuclear envelope and all major organelles, it considers current knowledge and progress towards unifying themes that will elucidate the mechanisms by which cells generate the correct complement of organelles and adapt and change it in response to environmental and developmental signals.
APA, Harvard, Vancouver, ISO, and other styles
5

Costello, Rona, David M. Emms, and Steven Kelly. "Gene Duplication Accelerates the Pace of Protein Gain and Loss from Plant Organelles." Molecular Biology and Evolution 37, no. 4 (November 21, 2019): 969–81. http://dx.doi.org/10.1093/molbev/msz275.

Full text
Abstract:
Abstract Organelle biogenesis and function is dependent on the concerted action of both organellar-encoded (if present) and nuclear-encoded proteins. Differences between homologous organelles across the Plant Kingdom arise, in part, as a result of differences in the cohort of nuclear-encoded proteins that are targeted to them. However, neither the rate at which differences in protein targeting accumulate nor the evolutionary consequences of these changes are known. Using phylogenomic approaches coupled to ancestral state estimation, we show that the plant organellar proteome has diversified in proportion with molecular sequence evolution such that the proteomes of plant chloroplasts and mitochondria lose or gain on average 3.6 proteins per million years. We further demonstrate that changes in organellar protein targeting are associated with an increase in the rate of molecular sequence evolution and that such changes predominantly occur in genes with regulatory rather than metabolic functions. Finally, we show that gain and loss of protein target signals occurs at a higher rate following gene duplication, revealing that gene and genome duplication are a key facilitator of plant organelle evolution.
APA, Harvard, Vancouver, ISO, and other styles
6

Okamoto, Koji. "Organellophagy: Eliminating cellular building blocks via selective autophagy." Journal of Cell Biology 205, no. 4 (May 26, 2014): 435–45. http://dx.doi.org/10.1083/jcb.201402054.

Full text
Abstract:
Maintenance of organellar quality and quantity is critical for cellular homeostasis and adaptation to variable environments. Emerging evidence demonstrates that this kind of control is achieved by selective elimination of organelles via autophagy, termed organellophagy. Organellophagy consists of three key steps: induction, cargo tagging, and sequestration, which involve signaling pathways, organellar landmark molecules, and core autophagy-related proteins, respectively. In addition, posttranslational modifications such as phosphorylation and ubiquitination play important roles in recruiting and tailoring the autophagy machinery to each organelle. The basic principles underlying organellophagy are conserved from yeast to mammals, highlighting its biological relevance in eukaryotic cells.
APA, Harvard, Vancouver, ISO, and other styles
7

Haggie, Peter M., and A. S. Verkman. "Defective organellar acidification as a cause of cystic fibrosis lung disease: reexamination of a recurring hypothesis." American Journal of Physiology-Lung Cellular and Molecular Physiology 296, no. 6 (June 2009): L859—L867. http://dx.doi.org/10.1152/ajplung.00018.2009.

Full text
Abstract:
The cellular mechanisms by which loss-of-function mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) chloride channel produce cystic fibrosis (CF) lung disease remain uncertain. Defective organellar function has been proposed as an important determinant in the pathogenesis of CF lung disease. According to one hypothesis, reduced CFTR chloride conductance in organelles in CF impairs their acidification by preventing chloride entry into the organelle lumen, which is needed to balance the positive charge produced by proton entry. According to a different hypothesis, CFTR mutation hyperacidifies organelles by an indirect mechanism involving unregulated sodium efflux through epithelial sodium channels. There are reports of defective Golgi, endosomal and lysosomal acidification in CF epithelial cells, defective phagolysosomal acidification in CF alveolar macrophages, and organellar hyperacidification in CF respiratory epithelial cells. The common theme relating too high or low organellar pH to cellular dysfunction and CF pathogenesis is impaired functioning of organellar enzymes, such as those involved in ceramide metabolism and protein processing in epithelial cells and antimicrobial activity in alveolar macrophages. We review here the evidence for defective organellar acidification in CF. Significant technical and conceptual concerns are discussed regarding the validity of data showing too high/low organellar pH in CF cells, and rigorous measurements of organellar pH in CF cells are reviewed that fail to support defective organellar acidification in CF. Indeed, there is an expanding body of evidence supporting the involvement of non-CFTR chloride channels in organellar acidification. We conclude that biologically significant involvement of CFTR in organellar acidification is unlikely.
APA, Harvard, Vancouver, ISO, and other styles
8

Hume, Alistair N., and Miguel C. Seabra. "Melanosomes on the move: a model to understand organelle dynamics." Biochemical Society Transactions 39, no. 5 (September 21, 2011): 1191–96. http://dx.doi.org/10.1042/bst0391191.

Full text
Abstract:
Advances in live-cell microscopy have revealed the extraordinarily dynamic nature of intracellular organelles. Moreover, movement appears to be critical in establishing and maintaining intracellular organization and organellar and cellular function. Motility is regulated by the activity of organelle-associated motor proteins, kinesins, dyneins and myosins, which move cargo along polar MT (microtubule) and actin tracks. However, in most instances, the motors that move specific organelles remain mysterious. Over recent years, pigment granules, or melanosomes, within pigment cells have provided an excellent model for understanding the molecular mechanisms by which motor proteins associate with and move intracellular organelles. In the present paper, we discuss recent discoveries that shed light on the mechanisms of melanosome transport and highlight future prospects for the use of pigment cells in unravelling general molecular mechanisms of intracellular transport.
APA, Harvard, Vancouver, ISO, and other styles
9

Wang, Yan, Jennifer Selinski, Chunli Mao, Yanqiao Zhu, Oliver Berkowitz, and James Whelan. "Linking mitochondrial and chloroplast retrograde signalling in plants." Philosophical Transactions of the Royal Society B: Biological Sciences 375, no. 1801 (May 4, 2020): 20190410. http://dx.doi.org/10.1098/rstb.2019.0410.

Full text
Abstract:
Retrograde signalling refers to the regulation of nuclear gene expression in response to functional changes in organelles. In plants, the two energy-converting organelles, mitochondria and chloroplasts, are tightly coordinated to balance their activities. Although our understanding of components involved in retrograde signalling has greatly increased in the last decade, studies on the regulation of the two organelle signalling pathways have been largely independent. Thus, the mechanism of how mitochondrial and chloroplastic retrograde signals are integrated is largely unknown. Here, we summarize recent findings on the function of mitochondrial signalling components and their links to chloroplast retrograde responses. From this, a picture emerges showing that the major regulators are integrators of both organellar retrograde signalling pathways. This article is part of the theme issue ‘Retrograde signalling from endosymbiotic organelles’.
APA, Harvard, Vancouver, ISO, and other styles
10

Robles, Pedro, and Víctor Quesada. "Transcriptional and Post-transcriptional Regulation of Organellar Gene Expression (OGE) and Its Roles in Plant Salt Tolerance." International Journal of Molecular Sciences 20, no. 5 (February 28, 2019): 1056. http://dx.doi.org/10.3390/ijms20051056.

Full text
Abstract:
Given their endosymbiotic origin, chloroplasts and mitochondria genomes harbor only between 100 and 200 genes that encode the proteins involved in organellar gene expression (OGE), photosynthesis, and the electron transport chain. However, as the activity of these organelles also needs a few thousand proteins encoded by the nuclear genome, a close coordination of the gene expression between the nucleus and organelles must exist. In line with this, OGE regulation is crucial for plant growth and development, and is achieved mainly through post-transcriptional mechanisms performed by nuclear genes. In this way, the nucleus controls the activity of organelles and these, in turn, transmit information about their functional state to the nucleus by modulating nuclear expression according to the organelles’ physiological requirements. This adjusts organelle function to plant physiological, developmental, or growth demands. Therefore, OGE must appropriately respond to both the endogenous signals and exogenous environmental cues that can jeopardize plant survival. As sessile organisms, plants have to respond to adverse conditions to acclimate and adapt to them. Salinity is a major abiotic stress that negatively affects plant development and growth, disrupts chloroplast and mitochondria function, and leads to reduced yields. Information on the effects that the disturbance of the OGE function has on plant tolerance to salinity is still quite fragmented. Nonetheless, many plant mutants which display altered responses to salinity have been characterized in recent years, and interestingly, several are affected in nuclear genes encoding organelle-localized proteins that regulate the expression of organelle genes. These results strongly support a link between OGE and plant salt tolerance, likely through retrograde signaling. Our review analyzes recent findings on the OGE functions required by plants to respond and tolerate salinity, and highlights the fundamental role that chloroplast and mitochondrion homeostasis plays in plant adaptation to salt stress.
APA, Harvard, Vancouver, ISO, and other styles
More sources

Dissertations / Theses on the topic "Organell"

1

Schwarz, Elisabeth. "Die Rolle des mitochondrialen Hsp70-Systems bei verschiedenen Prozessen der Organell-Biogenese." [S.l. : s.n.], 2000. http://deposit.ddb.de/cgi-bin/dokserv?idn=961717335.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Cerjan, Dijana. "INTRACELLULAR DISTRIBUTION PATTERNS OF ORGANELL SPECIFIC PROTEINS USING IMMUNOHISTOCHEMICAL STAINING OF TISSUE MICRO ARRAYS." Thesis, Uppsala University, Department of Medical Biochemistry and Microbiology, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-6154.

Full text
Abstract:

The knowledge of the human genome sequence, as revealed in the HUGO project, has created exciting new possibilities for biomedical research. The Swedish Human Proteome Resource (HPR) program aims to make use of this information to gain further insight into the human proteome. Recombinant proteins are generated from coding sequences identified from the human genome sequence and used to produce specific antibodies to target proteins. Antibodies are subsequently utilized for functional analysis of the corresponding proteins using tissue micro arrays. The aim of my project was to investigate the possibility of distinguishing characteristic distribution patterns of intracellular proteins in the resolution capacity offered by light microscopy. A map of representative distribution patterns was created using immunohistological staining with commercially available antibodies toward well-characterised proteins in the cell. Such a map could then aid in interpreting the results of immunohistological staining of intracellular proteins using antibodies produced within the Human Proteome Resource program. Proteins manifested in nucleus, nuclear membrane and plasma membrane were clearly visible at the expected location. Proteins manifested in different organelles in the cytoplasm however, showed all a similar staining pattern, making determination of exact protein location uncertain. A possible explanation is the resolution of the light microscope not being sufficient to visualize certain proteins specific to organelles in the cytoplasm. Results may also have been influenced by the choice of secondary antibody, where the strenghtened signal generated by an enzyme labelled polymer may have a negative effect on depiction of details in the image generated.

APA, Harvard, Vancouver, ISO, and other styles
3

Freitag, Johannes [Verfasser], and Michael [Akademischer Betreuer] Bölker. "Neue Enzyme für ein altes Organell : kryptische peroxisomale Lokalisationssignale in Pilzen / Johannes Freitag. Betreuer: Michael Bölker." Marburg : Philipps-Universität Marburg, 2014. http://d-nb.info/1050816994/34.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Mietner, Silke. "Charakterisierung von Organellen und Signalwegen des Thrombozyten." kostenfrei, 2008. http://www.opus-bayern.de/uni-wuerzburg/volltexte/2008/3121/.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Eriksson, Therese. "Organelle movement in melanophores: Effects of Panax ginseng, ginsenosides and quercetin." Licentiate thesis, Linköpings universitet, Farmakologi, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-19973.

Full text
Abstract:
Panax ginseng is a traditional herb that has been used for over 2000 years to promote health and longevity. Active components of ginseng include ginsenosides, polysaccharides, flavonoids, polyacetylenes, peptides, vitamins, phenols and enzymes, of which the ginsenosides are considered to be the major bioactive constituents. Although widely used, the exact mechanisms of ginseng and its compounds remain unclear. In this thesis we use melanophores from Xenopus laevis to investigate the effects of Panax ginseng extract G115 and its constituents on organelle transport and signalling. Due to coordinated bidirectional movement of their pigmented granules (melanosomes), in response to defined chemical signals, melanophores are capable of fast colour changes and provide a great model for the study of intracellular transport. The movement is regulated by alterations in cyclic adenosine 3’:5’-monophosphate (cAMP) concentration, where a high or low level induce anterograde (dispersion) or retrograde (aggregation) transport respectively, resulting in a dark or light cell. Here we demonstrate that Panax ginseng and its constituents ginsenoside Rc and Rd and flavonoid quercetin induce a concentration-dependent anterograde transport of melanosomes. The effect of ginseng is shown to be independent of cAMP changes and protein kinase A activation. Upon incubation of melanophores with a combination of Rc or Rd and quercetin, a synergistic increase in anterograde movement was seen, indicating cooperation between the ginsenoside and flavonoid parts of ginseng. Protein kinase C (PKC) inhibitor Myristoylated EGF-R Fragment 651-658 decreased the anterograde movement stimulated by ginseng and ginsenoside Rc and Rd. Moreover, ginseng, but not ginsenosides or quercetin, stimulated an activation of 44/42-mitogen activated protein kinase (MAPK), previously shown to be involved in both aggregation and dispersion of melanosomes. PKC-inhibition did not affect the MAPK-activation, suggesting a role for PKC in the ginseng- and ginsenoside-induced dispersion but not as an upstream activator of MAPK.
Panax ginseng är ett av de vanligaste naturläkemedlen i världen och används traditionellt för att öka kroppens uthållighet, motståndskraft och styrka. Ginseng är ett komplext ämne bestående av ett antal olika substanser, inklusive ginsenosider, flavonoider, vitaminer och enzymer, av vilka de steroidlika ginsenosiderna anses vara de mest aktiva beståndsdelarna. Flavonoider (som finns i till exempel frukt och grönsaker) och ginseng har genom forskning visat sig motverka bland annat hjärt-och kärlsjukdomar, diabetes, cancer och demens. Trots den omfattande användningen är dock mekanismen för hur ginseng verkar fortfarande oklar. I den här studien har vi använt pigmentinnehållande celler, melanoforer, från afrikansk klogroda för att undersöka effekterna av Panax ginseng på pigment-transport och dess maskineri. Melanoforer har förmågan att snabbt ändra färg genom samordnad förflyttning av pigmentkorn fram och tillbaka i cellen, och utgör en utmärkt modell för studier av intracellulär transport. Förflyttningen regleras av förändringar i halten av cykliskt adenosin-monofosfat (cAMP) i cellen, där en hög eller låg koncentration medför spridning av pigment över hela cellen (dispergering) eller en ansamling i mitten (aggregering), vilket resulterar i mörka respektive ljusa celler. Här visar vi att Panax ginseng, ginsenosiderna Rc och Rd samt flavonoiden quercetin stimulerar en dispergering av pigmentkornen. När melanoforerna inkuberades med en kombination av ginsenosid Rc eller Rd och quercetin, kunde en synergistisk ökning av dispergeringen ses, vilket tyder på en samverkan mellan ginsenosid- och flavonoid-delarna av ginseng. Ett protein som tidigare visats vara viktigt för pigmenttransporten är mitogen-aktiverat protein kinas (MAPK), och här visar vi att också melanoforer stimulerade med ginseng, men dock inte med ginsenosider eller quercetin, innehåller aktiverat MAPK. Genom att blockera enzymet protein kinas C (PKC) (känd aktivator av dispergering), minskade den ginseng- och ginsenosid-inducerade dispergeringen, medan aktiveringen av MAPK inte påverkades alls. Detta pekar på en roll för PKC i pigment-transporten men inte som en aktivator av MAPK.
APA, Harvard, Vancouver, ISO, and other styles
6

Berglund, Jenny. "Structure-function studies of organelle assembly and receptor recognition in organelles assembled via the chaperone/usher pathway /." Uppsala : Dept. of Molecular Biology, Swedish Univ. of Agricultural Sciences, 2004. http://epsilon.slu.se/a441.pdf.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

Morley, Stewart Anthony. "Interactions Between the Organellar Pol1A, Pol1B, and Twinkle DNA Replication Proteins and Their Role in Plant Organelle DNA Replication." BYU ScholarsArchive, 2019. https://scholarsarchive.byu.edu/etd/8128.

Full text
Abstract:
Plants maintain organelle genomes that are descended from ancient microbes. Ages ago, these ancient microbes were engulfed by larger cells, beginning a process of co-evolution we now call the endo-symbiotic theory. Over time, DNA from the engulfed microbe was transferred to the genome of the larger engulfing cell, eventually losing the ability to be free-living, and establishing a permanent residency in the larger cell. Similarly, the larger cell came to rely so much on the microbe it had engulfed, that it too lost its ability to survive without it. Thus, mitochondria and plastids were born. Nearly all multicellular eukaryotes possess mitochondria; however, different evolutionary pressures have created drastically different genomes in plants versus animals. For one, animals have very compact, efficient mitochondrial genomes, with about 97% of the DNA coding for genes. These genomes are very consistent in size across different animal species. Plants, on the other hand, have mitochondrial genomes 10 to more than 100 times as large as animal mitochondrial genomes. Plants also use a variety of mechanisms to replicate and maintain their DNA. Central to these mechanisms are nuclear-encoded, organelle targeted replication proteins. To date, there are two DNA polymerases that have been identified in plant mitochondria and chloroplasts, Pol1A and Pol1B. There is also a DNA helicase-primase that localizes to mitochondria and chloroplasts called Twinkle, which has similarities to the gp4 protein from T7 phage. In this dissertation, we discuss the roles of the polymerases and the effects of mutating the Pol1A and Pol1B genes respectively. We show that organelle genome copy number decreases slightly and over time but with little effect on plant development. We also detail the interactions between Twinkle and Pol1A or Pol1B. Plants possess the same organellar proteins found in animal mitochondria, which are homologs to T7 phage DNA replication proteins. We show that similar to animals and some phage, plants utilize the same proteins in similar interactions to form the basis of a DNA replisome. However, we also show that plants mutated for Twinkle protein show no discernable growth defects, suggesting there are alternative replication mechanisms available to plant mitochondria that are not accessible in animals.
APA, Harvard, Vancouver, ISO, and other styles
8

Malchus, Nina Isabelle [Verfasser], and Michael [Akademischer Betreuer] Hausmann. "On the spatial organization of cell organelles and diffusion of proteins in organelle membranes / Nina Isabelle Malchus ; Betreuer: Michael Hausmann." Heidelberg : Universitätsbibliothek Heidelberg, 2011. http://d-nb.info/1179230477/34.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

González, González Luis. "Functional and structural analyses of the terminal organelle of Mycoplasma genitalium." Doctoral thesis, Universitat Autònoma de Barcelona, 2015. http://hdl.handle.net/10803/326466.

Full text
Abstract:
Mycoplamsa genitalium es un patógeno humano causante de uretritis no gonocócica y no causada por clamidias en hombres y de enfermedad pélvica inflamatoria y cervicitis. Los micoplasmas, además de ser muy interesantes para el estudio como células mínimas (dado el pequeño tamaño de su genoma), también presentan características únicas sólo presentes en este género. En particular, se ha detectado la presencia de mecanismos de adhesión y de motilidad, que además de estar implicados en el mecanismo de infección, sólo se encuentran en este género. En especial, el mecanismo de motilidad de M. genitalium consta de una estructura polar que contiene un característico citoesqueleto. Se conoce que este citoesqueleto está formado por varias proteínas implicadas en el proceso de adhesión y motilidad. En los tres primeros capítulos de esta tesis se ha determinado el papel de tres de estas proteínas: MG219, MG318 (también llamada P32) y MG386. El estudio se ha realizado gracias a la obtención de mutantes defectivos de estas proteínas. La proteína MG219 se ha hallado que es necesaria para el correcto funcionamiento de la maquinaria de motilidad de este organismo. Mediante fusión a proteínas fluorescentes se ha determinado la localización subcelular de esta proteína, que resulta localizar en la parte más cercana de la organela terminal respecto al cuerpo celular. Las células en ausencia de MG219 se mueven a una velocidad inferior a la mitad (y la mitad de frecuentemente) que las células de la cepa salvaje. Esta reducción de la velocidad es concomitante con la aparición de un mayor número de células en división y con múltiples organelas terminales. De una manera similar, las células de la cepa que carece la proteína P32 se mueven a velocidades inferiores (y con la mitad de frecuencia) que las células de la cepa salvaje. Además, se ha determinado que el N-terminal de P32 juega un papel importante en la estabilidad de las proteínas P110 y P140, las más importantes adhesinas de M. genitalium. También se ha establecido que la proteína P32 es crítica para la morfología de la parte más distal de la organela terminal. El último mutante generado en este trabajo, el defectivo para la proteína MG386, presenta importantes variaciones tanto a nivel de morfología celular como de motilidad. Las células de esta cepa presentan motilidad la mitad de frecuentemente que la cepa salvaje pero se mueven a una velocidad 1.7 veces superior. Sorprendentemente, esta cepa presenta un gran número de organelas terminales desancladas del cuerpo celular, sugiriendo un importantísimo papel de la proteína MG386 en el anclaje de la organela terminal al cuerpo celular. Se ha observado que la membrana alrededor del citoesqueleto se encuentra completamente recubierta por el complejo de adhesión o ‘nap’. Mediante estudios de microscopia electrónica se ha determinado la estructura a 3.5 nm por ctomografia crioelectrónica y a 1.9 nm por tinción negativa. Además, la tomografía crioelectrónica también ha desvelado la estructura a baja resolución del botón terminal del citoesqueleto, revelando que las placas que forman la mayor parte del citoesquelto son, en realidad, anillos de unos 20 nm de diámetro. Además, se han analizado por tomografía crioelectrónica 14 mutantes que carecen de diferentes proteínas (o dominios de éstas) relacionadas con motilidad y/o adhesión. El conjunto de todos estos datos aporta una visión global al conocimiento previo (y al generado en este trabajo) sobre el papel de las proteínas implicadas motilidad y formación del citoesqueleto de M. geniatlium.
Mycoplamsa genitalium is a human pathogen and the causative agent of non-gonococcal non-chlamydial urethritis in men and pelvic inflammatory disease and cervicitis. Mycoplasmas, besides being interesting as minimal cells (given the small size of its genome), also have unique features only present in its genus. In particular, the presence of mechanisms of adhesion and motility has been detected, and in addition of being involved in addition of being involved in the infection mechanism, are only found in this genus. In particular, the mechanism of motility of M. genitalium involves a polar structure containing characteristic cytoskeleton. It is known that the cytoskeleton is composed of several proteins involved in the adhesion and motility processes. In the first three chapters of this thesis dissertation the role of three of this proteins—MG219, MG318 (also called P32) and MG386—has been stablished. The study was conducted by obtaining null mutants strains of these proteins. The MG219 protein has been found to be necessary for the proper functionality of the motility machinery. By fusion to fluorescent proteins it has been determined the subcellular localization of this MG219, which located at the nearest part of the terminal organelle relative to the cell body. Cells in the absence of MG219 move slower than half speedy (and half frequently) the cells of the wild type strain. This speed reduction is concomitant with the appearance of a greater number of dividing cells and cell with multiple terminal organelles. In a similar manner, cells of the strain lacking P32 move at lower speeds (and with half also half frequently) than cells of the wild type strain. Furthermore, it has been determined that the N-terminal P32 plays an important role in protein stability P110 and P140, the major adhesins of M. genitalium. It has also been established that the P32 protein is critical to the morphology of the most distal part of the terminal organelle relative to the cell body. The last mutant generated in this work, the null mutant for MG386, presents significant alterations in both cell morphology and motility. The cells of this strain show motility half frequently than the wild type strain but move to a velocities as greater as1.7 times than the reference strain. Surprisingly, this strain has a high number of terminal organelles detached from the cell body, suggesting an important role of protein MG386 anchoring the organelle to the cell body. It has been observed that the membrane around the cytoskeleton is completely covered by the adhesion complex or "nap". By electron microscopy studies it has determined the structure by cryo-electron tomography at 3.5 nm and at 1.9 nm single particle by negative staining TEM of the purified P110 and P140 complex. Additionally, cryo-electron tomography also allowed to determine at low resolution the structure of the terminal button of the cytoskeleton, revealing that the plates forming most of the cytoskeleton are actually rings about 20 nm in diameter. In addition, 14 mutants lacking different proteins (or domains thereof) related to motility and / or adhesion have been analysed by cryo-electron tomography. All these data taken together provides an overview of the prior knowledge—in addition to the data generated in this work—of the role of the proteins involved motility and cytoskeleton formation in M. geniatlium.
APA, Harvard, Vancouver, ISO, and other styles
10

Mahon, Piers Seaburne Macmahon. "Localisation of organelle proteins." Thesis, University of Cambridge, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.621831.

Full text
APA, Harvard, Vancouver, ISO, and other styles
More sources

Books on the topic "Organell"

1

Rodionov, V. S. Sovremennye metody vydelenii͡a︡ organell i membrannykh sistem iz kletok rasteniĭ. Petrozavodsk: Karelʹskiĭ nauch. t͡s︡entr AN SSSR, 1990.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
2

Elli, Kohen, ed. Atlas of cell organelles fluorescence. Boca Raton: CRC Press, 2004.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
3

Jendrossek, Dieter, ed. Bacterial Organelles and Organelle-like Inclusions. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-60173-7.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Organelles in tumor diagnosis: An ultrastructural atlas. New York: Igaku-Shoin, 1996.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
5

Edward, Bittar E., and Bittar Neville, eds. Cellular organelles. Greenwich, Conn: JAI Press, 1995.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
6

Edward, Bittar E., and Bittar Neville, eds. Cellular organelles and the extracellular matrix. Greenwich, Conn: JAI Press, 1995.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
7

Organelle genes and genomes. New York: Oxford University Press, 1994.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
8

Pflieger, Delphine, and Jean Rossier, eds. Organelle Proteomics. Totowa, NJ: Humana Press, 2008. http://dx.doi.org/10.1007/978-1-59745-028-7.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Bullerwell, Charles E., ed. Organelle Genetics. Berlin, Heidelberg: Springer Berlin Heidelberg, 2012. http://dx.doi.org/10.1007/978-3-642-22380-8.

Full text
APA, Harvard, Vancouver, ISO, and other styles
10

Delphine, Pflieger, and Rossier Jean, eds. Organelle proteomics. Totowa, NJ: Humana, 2008.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
More sources

Book chapters on the topic "Organell"

1

Jendrossek, Dieter. "Polyphosphate Granules and Acidocalcisomes." In Bacterial Organelles and Organelle-like Inclusions, 1–17. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-60173-7_1.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Jendrossek, Dieter. "Carbonosomes." In Bacterial Organelles and Organelle-like Inclusions, 243–75. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-60173-7_10.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Dahl, Christiane. "Bacterial Intracellular Sulphur Globules." In Bacterial Organelles and Organelle-like Inclusions, 19–51. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-60173-7_2.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Schüler, Dirk, and Frank D. Müller. "Biosynthesis and Intracellular Organization of Magnetosomes in Magnetotactic Bacteria." In Bacterial Organelles and Organelle-like Inclusions, 53–70. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-60173-7_3.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Pfeifer, Felicitas. "Gas Vesicles of Archaea and Bacteria." In Bacterial Organelles and Organelle-like Inclusions, 71–106. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-60173-7_4.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Claret Fernández, Laura, Rob Mesman, and Laura van Niftrik. "The Anammoxosome Organelle: The Power Plant of Anaerobic Ammonium-Oxidizing (Anammox) Bacteria." In Bacterial Organelles and Organelle-like Inclusions, 107–23. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-60173-7_5.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

Heinhorst, Sabine, and Gordon C. Cannon. "Bacterial Microcompartments." In Bacterial Organelles and Organelle-like Inclusions, 125–47. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-60173-7_6.

Full text
APA, Harvard, Vancouver, ISO, and other styles
8

Watzer, Björn, Friederike Klemke, and Karl Forchhammer. "The Cyanophycin Granule Peptide from Cyanobacteria." In Bacterial Organelles and Organelle-like Inclusions, 149–75. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-60173-7_7.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Colpaert, Matthieu, Malika Chabi, Ugo Cenci, and Christophe Colleoni. "Storage Polysaccharides in Prokaryotes: Glycogen, Granulose, and Starch-Like Granules." In Bacterial Organelles and Organelle-like Inclusions, 177–210. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-60173-7_8.

Full text
APA, Harvard, Vancouver, ISO, and other styles
10

Steinbüchel, Alexander, and Marc Wältermann. "Wax Ester and Triacylglycerol Inclusions." In Bacterial Organelles and Organelle-like Inclusions, 211–42. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-60173-7_9.

Full text
APA, Harvard, Vancouver, ISO, and other styles

Conference papers on the topic "Organell"

1

Kuznetsov, Andrey V. "Modeling the Effect of Vesicle Traps on Mass Transfer and Traffic Jam Formation in Fast Axonal Transport." In 2010 14th International Heat Transfer Conference. ASMEDC, 2010. http://dx.doi.org/10.1115/ihtc14-22169.

Full text
Abstract:
This paper simulates effects of structural changes in the microtubule (MT) system on mass transfer in an axon. Understanding this process is important for understanding the underlying reasons for many neurodegenerative diseases, such as Alzheimer’s disease. In particular, it is investigated how the degree of polar mismatching in an MT swirl affects organelle trap regions in the axon and inhibiting transport of organelles down the axon. The model is based on modified Smith-Simmons equations governing molecular-motor-assisted transport in neurons. It is established that the structure that develops as a result of a region with disoriented MTs (the MT swirl) consists of two organelle traps, the trap to the left of the swirl region accumulates plus-end oriented organelles and the trap to the right of this region accumulates minus-end oriented organelles. The presence of such a structure is shown to decrease the transport of organelles toward the synapse of the axon. Four cases with a different degree of polar mismatching in the swirl region are investigated; the results are compared with simulations for a healthy axon, in which case organelle traps are absent.
APA, Harvard, Vancouver, ISO, and other styles
2

Tran, Duc Hoa, Michel Meunier, and Farida Cheriet. "OrgaNet: A Robust Network for Subcellular Organelles Classification in Fluorescence Microscopy Images." In 2020 42nd Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC) in conjunction with the 43rd Annual Conference of the Canadian Medical and Biological Engineering Society. IEEE, 2020. http://dx.doi.org/10.1109/embc44109.2020.9175162.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Shou, Jingwen, Fanghao Hu, Robert Oda, Wei Min, and Yasuyuki Ozeki. "High-speed super-multiplex organelle imaging." In Advanced Chemical Microscopy for Life Science and Translational Medicine, edited by Garth J. Simpson, Ji-Xin Cheng, and Wei Min. SPIE, 2020. http://dx.doi.org/10.1117/12.2544808.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Kohen, Elli, Joseph G. Hirschberg, Cahide Kohen, Dietrich O. Schachtschabel, Marco Monti, and Rita Stanikunaite. "Fluorescence spectral imaging of organelle interaction." In BiOS 2000 The International Symposium on Biomedical Optics, edited by Daniel L. Farkas and Robert C. Leif. SPIE, 2000. http://dx.doi.org/10.1117/12.384215.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Dhar, Shanta. "Abstract B56: Organelle targeted photodynamic therapy." In Abstracts: Second AACR International Conference on Frontiers in Basic Cancer Research--Sep 14-18, 2011; San Francisco, CA. American Association for Cancer Research, 2011. http://dx.doi.org/10.1158/1538-7445.fbcr11-b56.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

"The variability of organelle genomes in barley." In Plant Genetics, Genomics, Bioinformatics, and Biotechnology. Novosibirsk ICG SB RAS 2021, 2021. http://dx.doi.org/10.18699/plantgen2021-190.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

Amorim, Marianny Rodrigues Costa, Letícia Oliveira Martins, and Andreia Juliana Rodrigues Caldeira. "ORIGEM E IMPORTÂNCIA FILOGENÉTICA DO CPDNA." In I Congresso Nacional On-line de Biologia Celular e Estrutural. Revista Multidisciplinar em Saúde, 2021. http://dx.doi.org/10.51161/rems/1946.

Full text
Abstract:
Introdução: O genoma do cloroplasto é mais conservado que o genoma nuclear e as mudanças de estrutura, ordem ou conteúdo de sequências do DNA cloroplasmático (cpDNA) são frequentemente usadas para mensurar a diversidade genética vegetal. Objetivo: Realizar uma revisão bibliográfica sobre a origem e importância filogenética do cpDNA. Material e métodos: foi realizada uma busca a partir de base dados como SciELO Brasil e Web of Science. Resultado: Cloroplasto é plastídio com DNA próprio. É considerada uma organela semiautônoma, devido a capacidade de sintetizar algumas proteínas. A origem evolutiva de plastídios está relacionada a antigos procariotos que viviam em simbiose dentro de eucariotos e que, ao longo da evolução, no ambiente citoplasmático, perdeu a maioria dos seus genes. Neste processo evolutivo, as bactérias precursoras do cloroplasto, transferiram parte de seu material genético para o DNA da célula hospedeira, contando assim com o genoma da célula hospedeira para produzir muitas de suas proteínas. O genoma cloroplástico é relativamente simples e possui uma estrutura circular com apenas 60 a 200 Kpb. Poucos genes cloroplasmáticos possuem íntrons e o espaço intergênico é pequeno, separados por poucos pares de bases. O número de proteínas codificadas pelo cpDNA é pequeno, mas o cloroplasto realiza sua própria replicação e transcrição de DNA e síntese proteica. Esses processos ocorrem na matriz, e, embora as proteínas que medeiam esse processo genético sejam específicas das organelas, a maioria delas é codificada pelo genoma nuclear, por isso o cpDNA é considerado uma organela especializada. Cada cloroplasto possui várias cópias do cpDNA e existem vários cloroplastos por célula. Isto multiplica o conteúdo da sequência básica de cpDNA por célula em dezenas a centenas de vezes. Conclusão: Estudos de cpDNA podem ser utilizados em várias áreas da biologia de plantas como: estudos evolutivos e filogenéticos (estabelecer relações filogenéticas entre espécies, gêneros e famílias), busca da base genética de doenças, clonagem gênica e reprodução, contribuindo para a expansão das pesquisas botânicas e agronômicas. Além disso, o sequenciamento de cpDNA revela características específicas de cada grupo de planta e de seu funcionamento, os quais podem ser amplamente aplicados através de técnicas da biotecnologia.
APA, Harvard, Vancouver, ISO, and other styles
8

Nawa, Yasunori, Wataru Inami, Atsushi Ono, Sheng Lin, Yoshimasa Kawata, and Susumu Terakawa. "Label-free cell organelle imaging by D-EXA microscopy." In JSAP-OSA Joint Symposia. Washington, D.C.: OSA, 2014. http://dx.doi.org/10.1364/jsap.2014.19a_c4_8.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Guirguis, Mark, Katelyn Rimkunas, Michael Raymond, and Leo Q. Wan. "Cell Organelle Positioning of Micropatterned Single C2C12 Mouse Myoblasts." In 2013 39th Annual Northeast Bioengineering Conference (NEBEC). IEEE, 2013. http://dx.doi.org/10.1109/nebec.2013.168.

Full text
APA, Harvard, Vancouver, ISO, and other styles
10

Grenier, Marie-Claude, Louis-Gilles Durand, and Jacques A. de Guise. "Comparative study of texture measurements for cellular organelle recognition." In Electronic Imaging '91, San Jose,CA, edited by Alan C. Bovik and Vyvyan Howard. SPIE, 1991. http://dx.doi.org/10.1117/12.44293.

Full text
APA, Harvard, Vancouver, ISO, and other styles

Reports on the topic "Organell"

1

Ostersetzer-Biran, Oren, and Alice Barkan. Nuclear Encoded RNA Splicing Factors in Plant Mitochondria. United States Department of Agriculture, February 2009. http://dx.doi.org/10.32747/2009.7592111.bard.

Full text
Abstract:
Mitochondria are the site of respiration and numerous other metabolic processes required for plant growth and development. Increased demands for metabolic energy are observed during different stages in the plants life cycle, but are particularly ample during germination and reproductive organ development. These activities are dependent upon the tight regulation of the expression and accumulation of various organellar proteins. Plant mitochondria contain their own genomes (mtDNA), which encode for a small number of genes required in organellar genome expression and respiration. Yet, the vast majority of the organellar proteins are encoded by nuclear genes, thus necessitating complex mechanisms to coordinate the expression and accumulation of proteins encoded by the two remote genomes. Many organellar genes are interrupted by intervening sequences (introns), which are removed from the primary presequences via splicing. According to conserved features of their sequences these introns are all classified as “group-II”. Their splicing is necessary for organellar activity and is dependent upon nuclear-encoded RNA-binding cofactors. However, to-date, only a tiny fraction of the proteins expected to be involved in these activities have been identified. Accordingly, this project aimed to identify nuclear-encoded proteins required for mitochondrial RNA splicing in plants, and to analyze their specific roles in the splicing of group-II intron RNAs. In non-plant systems, group-II intron splicing is mediated by proteins encoded within the introns themselves, known as maturases, which act specifically in the splicing of the introns in which they are encoded. Only one mitochondrial intron in plants has retained its maturaseORF (matR), but its roles in organellar intron splicing are unknown. Clues to other proteins required for organellar intron splicing are scarce, but these are likely encoded in the nucleus as there are no other obvious candidates among the remaining ORFs within the mtDNA. Through genetic screens in maize, the Barkan lab identified numerous nuclear genes that are required for the splicing of many of the introns within the plastid genome. Several of these genes are related to one another (i.e. crs1, caf1, caf2, and cfm2) in that they share a previously uncharacterized domain of archaeal origin, the CRM domain. The Arabidopsis genome contains 16 CRM-related genes, which contain between one and four repeats of the domain. Several of these are predicted to the mitochondria and are thus postulated to act in the splicing of group-II introns in the organelle(s) to which they are localized. In addition, plant genomes also harbor several genes that are closely related to group-II intron-encoded maturases (nMats), which exist in the nucleus as 'self-standing' ORFs, out of the context of their cognate "host" group-II introns and are predicted to reside within the mitochondria. The similarity with known group-II intron splicing factors identified in other systems and their predicted localization to mitochondria in plants suggest that nuclear-encoded CRM and nMat related proteins may function in the splicing of mitochondrial-encoded introns. In this proposal we proposed to (i) establish the intracellular locations of several CRM and nMat proteins; (ii) to test whether mutations in their genes impairs the splicing of mitochondrial introns; and to (iii) determine whether these proteins are bound to the mitochondrial introns in vivo.
APA, Harvard, Vancouver, ISO, and other styles
2

Sadot, Einat, Christopher Staiger, and Mohamad Abu-Abied. Studies of Novel Cytoskeletal Regulatory Proteins that are Involved in Abiotic Stress Signaling. United States Department of Agriculture, September 2011. http://dx.doi.org/10.32747/2011.7592652.bard.

Full text
Abstract:
In the original proposal we planned to focus on two proteins related to the actin cytoskeleton: TCH2, a touch-induced calmodulin-like protein which was found by us to interact with the IQ domain of myosin VIII, ATM1; and ERD10, a dehydrin which was found to associate with actin filaments. As reported previously, no other dehydrins were found to interact with actin filaments. In addition so far we were unsuccessful in confirming the interaction of TCH2 with myosin VIII using other methods. In addition, no other myosin light chain candidates were found in a yeast two hybrid survey. Nevertheless we have made a significant progress in our studies of the role of myosins in plant cells. Plant myosins have been implicated in various cellular activities, such as cytoplasmic streaming (1, 2), plasmodesmata function (3-5), organelle movement (6-10), cytokinesis (4, 11, 12), endocytosis (4, 5, 13-15) and targeted RNA transport (16). Plant myosins belong to two main groups of unconventional myosins: myosin XI and myosin VIII, both closely related to myosin V (17-19). The Arabidopsis myosin family contains 17 members: 13 myosin XI and four myosin VIII (19, 20). The data obtained from our research of myosins was published in two papers acknowledging BARD funding. To address whether specific myosins are involved with the motility of specific organelles, we cloned the cDNAs from neck to tail of all 17 Arabidopsis myosins. These were fused to GFP and used as dominant negative mutants that interact with their cargo but are unable to walk along actin filaments. Therefore arrested organelle movement in the presence of such a construct shows that a particular myosin is involved with the movement of that particular organelle. While no mutually exclusive connections between specific myosins and organelles were found, based on overexpression of dominant negative tail constructs, a group of six myosins (XIC, XIE, XIK, XI-I, MYA1 and MYA2) were found to be more important for the motility of Golgi bodies and mitochondria in Nicotiana benthamiana and Nicotiana tabacum (8). Further deep and thorough analysis of myosin XIK revealed a potential regulation by head and tail interaction (Avisar et al., 2011). A similar regulatory mechanism has been reported for animal myosin V and VIIa (21, 22). In was shown that myosin V in the inhibited state is in a folded conformation such that the tail domain interacts with the head domain, inhibiting its ATPase and actinbinding activities. Cargo binding, high Ca2+, and/or phosphorylation may reduce the interaction between the head and tail domains, thus restoring its activity (23). Our collaborative work focuses on the characterization of the head tail interaction of myosin XIK. For this purpose the Israeli group built yeast expression vectors encoding the myosin XIK head. In addition, GST fusions of the wild-type tail as well as a tail mutated in the amino acids that mediate head to tail interaction. These were sent to the US group who is working on the isolation of recombinant proteins and performing the in vitro assays. While stress signals involve changes in Ca2+ levels in plants cells, the cytoplasmic streaming is sensitive to Ca2+. Therefore plant myosin activity is possibly regulated by stress. This finding is directly related to the goal of the original proposal.
APA, Harvard, Vancouver, ISO, and other styles
3

Sally A. Mackenzie. Influence of Translation Initiation on Organellar Protein Targeting in Arabidopsis. Office of Scientific and Technical Information (OSTI), April 2011. http://dx.doi.org/10.2172/1011492.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Matsuzaki, Satoshi. Hole Burning Imaging Studies of Cancerous and Analogous Normal Ovarian Tissues Utilizing Organelle Specific Dyes. Office of Scientific and Technical Information (OSTI), January 2004. http://dx.doi.org/10.2172/837275.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Friedman, Haya, Chris Watkins, Susan Lurie, and Susheng Gan. Dark-induced Reactive Oxygen Species Accumulation and Inhibition by Gibberellins: Towards Inhibition of Postharvest Senescence. United States Department of Agriculture, December 2009. http://dx.doi.org/10.32747/2009.7613883.bard.

Full text
Abstract:
Dark-induced senescence could pose a major problem in export of various crops including cuttings. The assumption of this work was that ROS which is increased at a specific organelle can serve as a signal for activation of cell senescence program. Hormones which reduce senescence in several crops like gibberellic acid (GA) and possibly cytokinin (CK) may reduce senescence by inhibiting this signal. In this study we worked on Pelargonium cuttings as well as Arabidopsis rosette. In Pelargonium the increase in ROS occurred concomitantly with increase in two SAGs, and the increase persisted in isolated chloroplasts. In Arabidopsis we used two recentlydeveloped technologies to examine these hypotheses; one is a transcriptome approach which, on one hand, enabled to monitor expression of genes within the antioxidants network, and on the other hand, determine organelle-specific ROS-related transcriptome footprint. This last approach was further developed to an assay (so called ROSmeter) for determination of the ROS-footprint resulting from defined ROS stresses. The second approach involved the monitoring of changes in the redox poise in different organelles by measuring fluorescence ratio of redox-sensitive GFP (roGFP) directed to plastids, mitochondria, peroxisome and cytoplasm. By using the roGFP we determined that the mitochondria environment is oxidized as early as the first day under darkness, and this is followed by oxidation of the peroxisome on the second day and the cytoplast on the third day. The plastids became less oxidized at the first day of darkness and this was followed by a gradual increase in oxidation. The results with the ROS-related transcriptome footprint showed early changes in ROS-related transcriptome footprint emanating from mitochondria and peroxisomes. Taken together these results suggest that the first ROS-related change occurred in mitochondria and peroxisomes. The analysis of antioxidative gene’s network did not yield any clear results about the changes occurring in antioxidative status during extended darkness. Nevertheless, there is a reduction in expression of many of the plastids antioxidative related genes. This may explain a later increase in the oxidation poise of the plastids, occurring concomitantly with increase in cell death. Gibberellic acid (GA) prevented senescence in Pelargonium leaves; however, in Arabidopsis it did not prevent chlorophyll degradation, but prevented upregulation of SAGs (Apendix Fig. 1). Gibberellic acid prevented in Pelargonium the increase in ROS in chloroplast, and we suggested that this prevents the destruction of the chloroplasts and hence, the tissue remains green. In Arabidopsis, reduction in endogenous GA and BA are probably not causing dark-induced senescence, nevertheless, these materials have some effect at preventing senescence. Neither GA nor CK had any effect on transcriptome footprint related to ROS in the various organelles, however while GA reduced expression of few general ROS-related genes, BA mainly prevented the decrease in chloroplasts genes. Taken together, GA and BA act by different pathways to inhibit senescence and GA might act via ROS reduction. Therefore, application of both hormones may act synergistically to prevent darkinduced senescence of various crops.
APA, Harvard, Vancouver, ISO, and other styles
6

Ostersetzer-Biran, Oren, and Jeffrey Mower. Novel strategies to induce male sterility and restore fertility in Brassicaceae crops. United States Department of Agriculture, January 2016. http://dx.doi.org/10.32747/2016.7604267.bard.

Full text
Abstract:
Abstract Mitochondria are the site of respiration and numerous other metabolic processes required for plant growth and development. Increased demands for metabolic energy are observed during different stages in the plants life cycle, but are particularly ample during germination and reproductive organ development. These activities are dependent upon the tight regulation of the expression and accumulation of various organellar proteins. Plant mitochondria contain their own genomes (mtDNA), which encode for rRNAs, tRNAs and some mitochondrial proteins. Although all mitochondria have probably evolved from a common alpha-proteobacterial ancestor, notable genomic reorganizations have occurred in the mtDNAs of different eukaryotic lineages. Plant mtDNAs are notably larger and more variable in size (ranging from 70~11,000 kbp in size) than the mrDNAs in higher animals (16~19 kbp). Another unique feature of plant mitochondria includes the presence of both circular and linear DNA fragments, which undergo intra- and intermolecular recombination. DNA-seq data indicate that such recombination events result with diverged mitochondrial genome configurations, even within a single plant species. One common plant phenotype that emerges as a consequence of altered mtDNA configuration is cytoplasmic male sterility CMS (i.e. reduced production of functional pollen). The maternally-inherited male sterility phenotype is highly valuable agriculturally. CMS forces the production of F1 hybrids, particularly in predominantly self-pollinating crops, resulting in enhanced crop growth and productivity through heterosis (i.e. hybrid vigor or outbreeding enhancement). CMS lines have been implemented in some cereal and vegetables, but most crops still lack a CMS system. This work focuses on the analysis of the molecular basis of CMS. We also aim to induce nuclear or organellar induced male-sterility in plants, and to develop a novel approach for fertility restoration. Our work focuses on Brassicaceae, a large family of flowering plants that includes Arabidopsis thaliana, a key model organism in plant sciences, as well as many crops of major economic importance (e.g., broccoli, cauliflower, cabbage, and various seeds for oil production). In spite of the genomic rearrangements in the mtDNAs of plants, the number of genes and the coding sequences are conserved among different mtDNAs in angiosperms (i.e. ~60 genes encoding different tRNAs, rRNAs, ribosomal proteins and subunits of the respiratory system). Yet, in addition to the known genes, plant mtDNAs also harbor numerous ORFs, most of which are not conserved among species and are currently of unknown function. Remarkably, and relevant to our study, CMS in plants is primarily associated with the expression of novel chimericORFs, which likely derive from recombination events within the mtDNAs. Whereas the CMS loci are localized to the mtDNAs, the factors that restore fertility (Rfs) are identified as nuclear-encoded RNA-binding proteins. Interestingly, nearly all of the Rf’s are identified as pentatricopeptide repeat (PPR) proteins, a large family of modular RNA-binding proteins that mediate several aspects of gene expression primarily in plant organelles. In this project we proposed to develop a system to test the ability of mtORFs in plants, which are closely related to known CMS factors. We will induce male fertility in various species of Brassicaceae, and test whether a down-relation in the expression of the recombinantCMS-genes restores fertility, using synthetically designed PPR proteins.
APA, Harvard, Vancouver, ISO, and other styles
7

Nelson, Nathan, and Randy Schekman. Functional Biogenesis of V-ATPase in the Vacuolar System of Plants and Fungi. United States Department of Agriculture, September 1996. http://dx.doi.org/10.32747/1996.7574342.bard.

Full text
Abstract:
The vacuolar H+-ATPase (V-ATPase) is one of the most fundamental enzymes in nature. It pumps protons into the vacuolar system of eukaryotic cells and provides the energy for numerous transport systems. Through our BARD grant we discovered a novel family of membrane chaperones that modulate the amount of membrane proteins. We also elucidated the mechanism by which assembly factors guide the membrane sector of V-ATPase from the endoplasmic reticulum to the Golgi apparatus. The major goal of the research was to understand the mechanism of action and biogenesis of V-ATPase in higher plants and fungi. The fundamental question of the extent of acidification in organelles of the vacuolar system was addressed by studying the V-ATPase of lemon fruit, constructing lemon cDNAs libraries and study their expression in mutant yeast cells. The biogenesis of the enzyme and its function in the Golgi apparatus was studied in yeast utilizing a gallery of secretory mutants available in our laboratories. One of the goals of this project is to determine biochemically and genetically how V-ATPase is assembled into the different membranes of a wide variety of organelles and what is the mechanism of its action.The results of this project advanced out knowledge along these lines.
APA, Harvard, Vancouver, ISO, and other styles
8

Stern, David, and Gadi Schuster. Manipulation of Gene Expression in the Chloroplast. United States Department of Agriculture, September 2000. http://dx.doi.org/10.32747/2000.7575289.bard.

Full text
Abstract:
The steady-state level of a given mRNA is determined by its rates of transcription and degradation. The stabilities of chloroplast mRNAs vary during plant development, in part regulating gene expression. Furthermore, the fitness of the organelle depends on its ability to destroy non-functional transcripts. In addition, there is a resurgent interest by the biotechnology community in chloroplast transformation due to the public concerns over pollen transmission of introduced traits or foreign proteins. Therefore, studies into basic gene expression mechanisms in the chloroplast will open the door to take advantage of these opportunities. This project was aimed at gaining mechanistic insights into mRNA processing and degradation in the chloroplast and to engineer transcripts of varying stability in Chlamydomonas reinhardtii cells. This research uncovered new and important information on chloroplast mRNA stability, processing, degradation and translation. In particular, the processing of the 3' untranslated regions of chloroplast mRNAs was shown to be important determinants in translation. The endonucleolytic site in the 3' untranslated region was characterized by site directed mutagensis. RNA polyadenylation has been characterized in the chloroplast of Chlamydomonas reinhardtii and chloroplast transformants carrying polyadenylated sequences were constructed and analyzed. Data obtained to date suggest that chloroplasts have gene regulatory mechanisms which are uniquely adapted to their post-endosymbiotic environment, including those that regulate RNA stability. An exciting point has been reached, because molecular genetic studies have defined critical RNA-protein interactions that participate in these processes. However, much remains to be learned about these multiple pathways, how they interact with each other, and how many nuclear genes are consecrated to overseeing them. Chlamydomonas is an ideal model system to extend our understanding of these areas, given its ease of manipulation and the existing knowledge base, some of which we have generated.
APA, Harvard, Vancouver, ISO, and other styles
9

Stern, David B., and Gadi Schuster. Manipulation of Gene Expression in the Chloroplast: Control of mRNA Stability and Transcription Termination. United States Department of Agriculture, December 1993. http://dx.doi.org/10.32747/1993.7568750.bard.

Full text
Abstract:
Chloroplasts are the site of photosynthesis and of other essential biosynthetic activities in plant cells. Chloroplasts are semi-autonomous organelles, since they contain their own genomes and protein biosynthetic machinery, but depend on the coordinate expression of nuclear genes to assemble macromolecular complexes. The bioeingineering of plants requires manipulation of chloroplast gene expression, and thus a knowledge of the molecular mechanisms that modulate mRNA and protein production. In this proposal the heterotrophic green alga Chlamydomonas reinhardtii has been used as a model system to understand the control and interrelationships between transcription termination, mRNA 3' end processing and mRNA stability in chloroplasts. Chlamydomonas is a unique and ideal system in which to address these issues, because the chloroplast can be easily manipulated by genetic transformation techniques. This research uncovered new and important information on chloroplast mRNA 3' end formation and mRNA stability. In particular, the 3' untranslated regions of chloroplast mRNAs were shown not to be efficient transcription terminators. The endonucleolytic site in the 3' untranslated region was characterized by site directed mutagensis and the role of several 3' untranslated regions in modulating RNA stability and translation has been studied. This information will allow us to experimentally manipulate the expression of chloroplast genes in vivo by post-transcriptional mechanisms, and should be widely applicable to other higher plant systems.
APA, Harvard, Vancouver, ISO, and other styles
10

McElwain, Terry F., Eugene Pipano, Guy H. Palmer, Varda Shkap, Stephn A. Hines, and Wendy C. Brown. Protection of Cattle against Babesiosis: Immunization against Babesia bovis with an Optimized RAP-1/Apical Complex Construct. United States Department of Agriculture, September 1999. http://dx.doi.org/10.32747/1999.7573063.bard.

Full text
Abstract:
Previous research and current efforts at control of babesiosis fall short of meeting the needs of countries where the disease is endemic, such as Israel, as well as the needs of exporting countries and countries bordering on endemic areas, such as the U.S. Our long-term goal is to develop improved methods of immunization against bovine babesiosis based on an understanding of the molecular mechanisms of immune protection and parasite targets of a protective immune response. In our previous BARD project, we established the basis for focusing on rhoptry antigens as components of a subunit vaccine against bovine babesiosis, and for additional research to better characterize rhoptry associated protein-1 (RAP-1) as a target of protective immunity. In this continuation BARD project, our objectives were to [1] optimize the immune response against RAP-1, and [2] identify additional rhoptry candidate vaccine antigens. The entire locus encoding B. bovis RAP-1 was sequenced, and the rap-1 open reading frame compared among several strains. Unlike B. bigemina, in which multiple gene copies with variant domains encode RAP-1, the B. bovis RAP-1 locus contains only two identical genes which are conserved among strains. Through testing of multiple truncated constructs of rRAP-1, one or more immunodominant T cell epitopes were mapped to the amino terminal half of RAP-1. At least one linear and one conformational B cell epitope have been demonstrated in the same amino terminal construct, which in B. bigemina RAP-1 also contains an epitope recognized by neutralizing antibody. The amine terminal half of the molecule represents the most highly conserved part of the gene family and contains motifs conserved broadly among the apicomplexa. In contrast, the carboxy terminal half of B. bovis RAP-1 is less well conserved and contains multiple repeats encoding a linear B cell epitope potentially capable of inducing an ineffective, T cell independent, type 2 immune response. Therefore, we are testing an amino terminal fragment of RAP-1 (RAP-1N) in an immunization trial in cattle. Cattle have beer immunized with RAP-1N or control antigen, and IL-12 with Ribi adjuvant. Evaluation of the immune response is ongoing, and challenge with virulent B. bovis will occur in the near future. While no new rhoptry antigens were identified, our studies did identify and characterize a new spherical body antigen (SBP3), and several heat shock proteins (HSP's). The SBP3 and HSP21 antigens stimulate T cells from immune cattle and are considered new vaccine candidates worthy of further testing. Overall, we conclude that a single RAP-1 vaccine construct representing the conserved amino terminal region of the molecule should be sufficient for immunization against all strains of B. bovis. While results of the ongoing immunization trial will direct our next research steps, results at this time are consistent with our long term goal of designing a subunit vaccine which contains only the epitopes relevant to induction of protective immunity. Parallel studies are defining the mechanisms of protective immunity. Apicomplexan protozoa, including babesiosis and malaria, cause persistent diseases for which control is inadequate. The apical organelles are defining features of these complex protozoa, and have been conserved through the evolutionary process, Past and current BARD projects on babesiosis have established the validity and potential of exploiting these conserved organelles in developing improved control methods applicable to all apicomplexan diseases.
APA, Harvard, Vancouver, ISO, and other styles
You might also be interested in the extended bibliographies on the topic 'Organell' for particular source types:
Journal articles Dissertations / Theses Books
We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!

To the bibliography