Journal articles: 'Protein hormone'

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Niessen, René W. L. M., Birgit A. Pfaffendorf, Augueste Sturk, Roy J. Lamping, Marianne C. L. Schaap, C. Erik Hack, and Marjolein Peters. "The Influence of Insulin, ß-Estradiol, Dexamethasone and Thyroid Hormone on the Secretion of Coagulant and Anticoagulant Proteins by HepG2 Cells." Thrombosis and Haemostasis 74, no. 02 (1995): 686–92. http://dx.doi.org/10.1055/s-0038-1649798.

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SummaryAs a basis for regulatory studies on the influence of hormones on (anti)coagulant protein production by hepatocytes, we examined the amounts of the plasma proteins antithrombin III (AT III), protein C, protein S, factor II, factor X, fibrinogen, and prealbumin produced by the hepatoma cell line HepG2, into the culture medium, in the absence and presence of insulin, β-estradiol, dexamethasone and thyroid hormone. Without hormones these cells produced large amounts of fibrinogen (2,452 ± 501 ng/mg cell protein), AT III (447 ± 16 ng/mg cell protein) and factor II (464 ± 31 ng/mg cell protein) and only small amounts of protein C (50 ± 7 ng/mg cell protein) and factor X (55 ± 5 ng/mg cell protein). Thyroid hormone had a slight but significant effect on the enrichment in the culture medium of the anticoagulant protein AT III (1.34-fold) but not on protein C (0.96-fold) and protein S (0.91-fold). This hormone also significantly increased the amounts of the coagulant proteins factor II (1.28-fold), factor X (1.45-fold) and fibrinogen (2.17-fold). Insulin had an overall stimulating effect on the amounts of all the proteins that were investigated. Neither dexamethasone nor ß-estradiol administration did substantially change the amounts of these proteins.We conclude that the HepG2 cell is a useful tool to study the hormonal regulation of the production of (anti)coagulant proteins. We studied the overall process of protein production, i.e., the amounts of proteins produced into the culture medium. Detailed studies have to be performed to establish the specific hormonal effects on the underlying processes, e.g., transcription, translation, cellular processing and transport, and secretion.

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Richardson, Samantha J., Julie A. Monk, Caroline A. Shepherdley, Lars O. E. Ebbesson, Frank Sin, Deborah M. Power, Peter B. Frappell, Josef Köhrle, and Marilyn B. Renfree. "Developmentally regulated thyroid hormone distributor proteins in marsupials, a reptile, and fish." American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 288, no. 5 (May 2005): R1264—R1272. http://dx.doi.org/10.1152/ajpregu.00793.2004.

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Thyroid hormones are essential for vertebrate development. There is a characteristic rise in thyroid hormone levels in blood during critical periods of thyroid hormone-regulated development. Thyroid hormones are lipophilic compounds, which readily partition from an aqueous environment into a lipid environment. Thyroid hormone distributor proteins are required to ensure adequate distribution of thyroid hormones, throughout the aqueous environment of the blood, and to counteract the avid partitioning of thyroid hormones into the lipid environment of cell membranes. In human blood, these proteins are albumin, transthyretin and thyroxine-binding globulin. We analyzed the developmental profile of thyroid hormone distributor proteins in serum from a representative of each order of marsupials ( M. eugenii; S.crassicaudata), a reptile ( C. porosus), in two species of salmonoid fishes ( S. salar; O. tshawytsch), and throughout a calendar year for sea bream ( S. aurata). We demonstrated that during development, these animals have a thyroid hormone distributor protein present in their blood which is not present in the adult blood. At least in mammals, this additional protein has higher affinity for thyroid hormones than the thyroid hormone distributor proteins in the blood of the adult. In fish, reptile and polyprotodont marsupial, this protein was transthyretin. In a diprotodont marsupial, it was thyroxine-binding globulin. We propose an hypothesis that an augmented thyroid hormone distributor protein network contributes to the rise in total thyroid hormone levels in the blood during development.

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De Feo, Pierpaolo. "Hormonal regulation of human protein metabolism." European Journal of Endocrinology 135, no. 1 (July 1996): 7–18. http://dx.doi.org/10.1530/eje.0.1350007.

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De Feo P. Hormonal regulation of human protein metabolism. Eur J Endocrinol 1996:135:7–18. ISSN 0804–4643 This review focuses on the effects of hormones on protein kinetics in humans. Most of the recent knowledge on the regulation of protein metabolism in humans has been obtained by tracing protein kinetics in vivo, using labelled isotopes of essential or non-essential amino acids. This technique allows the rates of the whole-body protein synthesis and breakdown to be estimated together with amino acid oxidation and the fractional synthetic rates of mixed muscle proteins or of single plasma proteins. Changes induced within these parameters by hormonal administration or endocrine diseases are also discussed. Hormones, on the basis of their net effect on protein balance (protein synthesis minus protein breakdown), are divided into two categories: those provided with an anabolic action and those with a prevalent catabolic action. The effects on protein metabolism of the following hormones are reviewed: insulin, growth hormone, IGF-I, adrenaline, androgens, estrogens, progesterone, glucagon, glucocorticosteroids, thyroid hormones. The review concludes with a report on the effects of multiple hormonal infusions on whole-body protein kinetics and a discussion on the potential role played by the concomitant increase of several hormones in the pathogenesis of protein wasting that complicates stress diseases. Pierpaolo De Feo, DIMISEM, Via E. Dal Pozzo, 06126 Perugia, Italy

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Engels, J. W., J. Glauder, H. Müllner, D. Tripier, E. Uhlmann, and W. Wetekam. "Enzymatic amidation of recombinant (Leu27) growth hormone releasing hormone-Gly45." "Protein Engineering, Design and Selection" 1, no. 3 (1987): 195–99. http://dx.doi.org/10.1093/protein/1.3.195.

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Campbell, Kenneth L., Nurit Haspel, Cassandra Gath, Nuzulul Kurniatash, Indira (Nouduri) Akkiraju, Naomi Stuffers, and Uma Vadher. "Protein hormone fragmentation in intercellular signaling: hormones as nested information systems." Biology of Reproduction 104, no. 4 (January 5, 2021): 887–901. http://dx.doi.org/10.1093/biolre/ioaa234.

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Abstract This study explores the hypothesis that protein hormones are nested information systems in which initial products of gene transcription, and their subsequent protein fragments, before and after secretion and initial target cell action, play additional physiological regulatory roles. The study produced four tools and key results: (1) a problem approach that proceeds, with examples and suggestions for in vivo organismal functional tests for peptide–protein interactions, from proteolytic breakdown prediction to models of hormone fragment modulation of protein–protein binding motifs in unrelated proteins; (2) a catalog of 461 known soluble human protein hormones and their predicted fragmentation patterns; (3) an analysis of the predicted proteolytic patterns of the canonical protein hormone transcripts demonstrating near-universal persistence of 9 ± 7 peptides of 8 ± 8 amino acids even after cleavage with 24 proteases from four protease classes; and (4) a coincidence analysis of the predicted proteolysis locations and the 1939 exon junctions within the transcripts that shows an excess (P < 0.001) of predicted proteolysis within 10 residues, especially at the exonal junction (P < 0.01). It appears all protein hormone transcripts generate multiple fragments the size of peptide hormones or protein–protein binding domains that may alter intracellular or extracellular functions by acting as modulators of metabolic enzymes, transduction factors, protein binding proteins, or hormone receptors. High proteolytic frequency at exonal junctions suggests proteolysis has evolved, as a complement to gene exon fusion, to extract structures or functions within single exons or protein segments to simplify the genome by discarding archaic one-exon genes.

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Pradhananga, Sarbendra, and Jon R. Sayers. "Natural synthesis: Biologics, biosimilars and biobetters in protein hormone therapy." Biochemist 34, no. 1 (February 1, 2012): 10–15. http://dx.doi.org/10.1042/bio03401010.

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Hormone therapies have been used since the early 20th Century and belong to a group of drugs that has recently become known as ‘biologics’. Biologics are medicinal products that have been produced by biological processes as opposed to chemically synthesized drugs. The term biologics spans a wide range of products that include therapeutics such as organs, tissue, cells, blood or blood components, vaccines and proteins. This ‘proteins’ subgroup can be further subdivided into therapeutics such as antibodies, enzymes and hormones. The first hormone therapeutics were extracted from human or animal sources; however, with the advent and development of cloning and protein production technologies from the late-20th Century onwards, protein hormone therapeutics are now produced by recombinant DNA technology.

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Fetissov, Sergueï O., Romain Legrand, and Nicolas Lucas. "Bacterial Protein Mimetic of Peptide Hormone as a New Class of Protein- based Drugs." Current Medicinal Chemistry 26, no. 3 (March 26, 2019): 546–53. http://dx.doi.org/10.2174/0929867324666171005110620.

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Specific peptide molecules classified as hormones, neuropeptides and cytokines are involved in intercellular signaling regulating various physiological processes in all organs and tissues. This justifies the peptidergic signaling as an attractive pharmacological target. Recently, a protein mimetic of a peptide hormone has been identified in Escherichia coli suggesting the potential use of specific bacterial proteins as a new type of peptide-like drugs. We review the scientific rational and technological approaches leading to the identification of the E. coli caseinolytic protease B (ClpB) homologue protein as a conformational mimetic of α-melanocyte-stimulating hormone (α-MSH), a melanocortin peptide critically involved in the regulation of energy homeostasis in humans and animals. Theoretical and experimental backgrounds for the validation of bacterial ClpB as a potential drug are discussed based on the known E. coli ClpB amino acid sequence homology with α-MSH. Using in silico analysis, we show that other protein sources containing similar to E. coli ClpB α-MSH-like epitopes with potential biological activity may exist in Enterobacteriaceae and in some Brassicaceae. Thus, the original approach leading to the identification of E. coli ClpB as an α-MSH mimetic protein can be applied for the identification of mimetic proteins of other peptide hormones and development of a new type of peptide-like protein-based drugs.

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Clapp, Carmen, Stéphanie Thebault, Michael C. Jeziorski, and Gonzalo Martínez De La Escalera. "Peptide Hormone Regulation of Angiogenesis." Physiological Reviews 89, no. 4 (October 2009): 1177–215. http://dx.doi.org/10.1152/physrev.00024.2009.

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It is now apparent that regulation of blood vessel growth contributes to the classical actions of hormones on development, growth, and reproduction. Endothelial cells are ideally positioned to respond to hormones, which act in concert with locally produced chemical mediators to regulate their growth, motility, function, and survival. Hormones affect angiogenesis either directly through actions on endothelial cells or indirectly by regulating proangiogenic factors like vascular endothelial growth factor. Importantly, the local microenvironment of endothelial cells can determine the outcome of hormone action on angiogenesis. Members of the growth hormone/prolactin/placental lactogen, the renin-angiotensin, and the kallikrein-kinin systems that exert stimulatory effects on angiogenesis can acquire antiangiogenic properties after undergoing proteolytic cleavage. In view of the opposing effects of hormonal fragments and precursor molecules, the regulation of the proteases responsible for specific protein cleavage represents an efficient mechanism for balancing angiogenesis. This review presents an overview of the actions on angiogenesis of the above-mentioned peptide hormonal families and addresses how specific proteolysis alters the final outcome of these actions in the context of health and disease.

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Toth, Michael J., Cynthia K. Sites, Dwight E. Matthews, and Peter R. Casson. "Ovarian suppression with gonadotropin-releasing hormone agonist reduces whole body protein turnover in women." American Journal of Physiology-Endocrinology and Metabolism 291, no. 3 (September 2006): E483—E490. http://dx.doi.org/10.1152/ajpendo.00600.2005.

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The age-related decline in fat-free mass is accelerated in women after menopause. The role of ovarian hormone deficiency in the regulation of fat-free mass, however, has not been clearly defined. To address this question, we examined the effect of ovarian hormone suppression on whole body protein metabolism. Whole body protein breakdown, oxidation, and synthesis were measured using [13C]leucine in young, healthy women with regular menstrual patterns before and after 2 mo of treatment with gonadotropin-releasing hormone agonist (GnRHa; n = 6) or placebo ( n = 7). Protein metabolism was measured under postabsorptive and euglycemic-hyperinsulinemic-hyperaminoacidemic conditions. Ovarian suppression did not alter whole body or regional fat-free mass or adiposity. In the postabsorptive state, GnRHa administration was associated with reductions in protein breakdown and synthesis ( P < 0.05), whereas no change in protein oxidation was noted. Under euglycemic-hyperinsulinemic-hyperaminoacidemic conditions, a similar reduction ( P < 0.05) in protein synthesis and breakdown was noted, whereas, protein oxidation increased ( P < 0.05) in the placebo group. Testosterone, steroid hormone precursors, insulin-like growth factor I, and their respective binding proteins were not altered by GnRHa administration, and changes in these hormones over time were not associated with GnRHa-induced alterations in protein metabolism, suggesting that changes in protein turnover are not due to an effect of ovarian suppression on other endocrine systems. Our findings provide evidence that endogenous ovarian hormones participate in the regulation of protein turnover in women.

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Moseley, Jane M., Matthew T. Gillespie, and Mark A. Thiede. "Parathyroid Hormone-Related Protein." Critical Reviews in Clinical Laboratory Sciences 32, no. 3 (January 1995): 299–343. http://dx.doi.org/10.3109/10408369509084687.

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Singer, Frederick R. "Parathyroid Hormone-Related Protein." Mayo Clinic Proceedings 65, no. 11 (November 1990): 1502–5. http://dx.doi.org/10.1016/s0025-6196(12)62172-7.

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Heath, D. A. "Parathyroid hormone related protein." Clinical Endocrinology 38, no. 2 (February 1993): 135–36. http://dx.doi.org/10.1111/j.1365-2265.1993.tb00984.x.

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NOGUCHI, Tadashi. "Hormone and protein metabolism." Journal of the agricultural chemical society of Japan 61, no. 10 (1987): 1297–99. http://dx.doi.org/10.1271/nogeikagaku1924.61.1297.

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Lloyd, Ricardo V. "Parathyroid Hormone-Related Protein." Advances in Anatomic Pathology 1, no. 2 (September 1994): 82–86. http://dx.doi.org/10.1097/00125480-199409000-00003.

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Martin, T. J. "Parathyroid hormone-related protein." Journal of Internal Medicine 233, no. 1 (January 1993): 1–4. http://dx.doi.org/10.1111/j.1365-2796.1993.tb00638.x.

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Carlsson-Bostedt, L., N. Frölander, S. Edén, T. Stigbrand, and B. von Schoultz. "Effects of oestrogen and human growth hormone on pregnancy-associated plasma proteins in the rat." Acta Endocrinologica 116, no. 2 (October 1987): 299–304. http://dx.doi.org/10.1530/acta.0.1160299.

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Abstract. The serum concentrations of pregnancy-associated murine protein-1 (PAMP-1), acute phase α2macroglobulin, albumin, transferrin, and complement factor 3(C3) were followed in male rats during continuous infusions of oestradiol-17β and human growth hormone. Three different patterns of protein response could be distinguished. A distinct acute phase response without any additive influence of the given hormones was recorded for α2-macroglobulin, whereas the levels of albumin, transferrin and C3 were virtually unaffected throughout the experiment. Growth hormone gave a rapid and pronounced increase of PAMP-1 levels, whereas the response to oestradiol of this 'steroid-sensitive' protein was significantly weaker and delayed. It is suggested that the apparent oestrogenic influence on certain pregnancy-associated plasma proteins is mediated via growth hormone.

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Brennan, Amelia J., Julie A. Sharp, Elie Khalil, Matthew R. Digby, Sonia L. Mailer, Christophe M. Lefèvre, and Kevin R. Nicholas. "A population of mammary epithelial cells do not require hormones or growth factors to survive." Journal of Endocrinology 196, no. 3 (January 4, 2008): 483–96. http://dx.doi.org/10.1677/joe-07-0537.

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Hormonal stimulation of mammary explants mimics many of the biochemical changes observed during lactogenesis. Previous studies using eutherian species conclude that mammary explants require addition of exogenous macromolecules to remain hormone responsive in culture. The present study examines the survival of mammary explants from the wallaby and mouse using milk protein gene expression as a functional marker of lactation and cell viability. Mammary explants from pregnant tammars and mice showed that milk protein gene expression was significantly elevated after 3 days of culture with lactogenic hormones. The subsequent removal of exogenous hormones from the media for 10 days resulted in the down-regulation of milk protein genes. Surprisingly, mammary explants remained hormone responsive and expression of milk protein genes was re-induced after a second challenge with lactogenic hormones. Furthermore, the alveolar architecture was maintained. Global functional microarray analysis showed that classic involution markers were not differentially expressed, although two stress-induced survival genes were significantly up-regulated. We report that a population of mammary epithelial cells have an intrinsic capacity to remain viable and hormone responsive for extended periods in chemically defined media without any exogenous macromolecules. We propose that the mammary explant culture model uncouples the first phase of involution, as milk accumulation that normally provides involution stimuli is absent in this culture model allowing a population of cells to survive.

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Carlson, Anne A., Marta B. Manser, Andrew J. Young, Andrew F. Russell, Neil R. Jordan, Alan S. McNeilly, and Tim Clutton-Brock. "Cortisol levels are positively associated with pup-feeding rates in male meerkats." Proceedings of the Royal Society B: Biological Sciences 273, no. 1586 (December 5, 2005): 571–77. http://dx.doi.org/10.1098/rspb.2005.3087.

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In societies of cooperative vertebrates, individual differences in contributions to offspring care are commonly substantial. Recent attempts to explain the causes of this variation have focused on correlations between contributions to care and the protein hormone prolactin, or the steroid hormone testosterone. However, such studies have seldom considered the importance of other hormones or controlled for non-hormonal factors that are correlative with both individual hormone levels and contributions to care. Using multivariate statistics, we show that hormone levels explain significant variation in contributions to pup-feeding by male meerkats, even after controlling for non-hormonal effects. However, long-term contributions to pup provisioning were significantly and positively correlated with plasma levels of cortisol rather than prolactin, while plasma levels of testosterone were not related to individual patterns of pup-feeding. Furthermore, a playback experiment that used pup begging calls to increase the feeding rates of male helpers gave rise to parallel increases in plasma cortisol levels, whilst prolactin and testosterone levels remained unchanged. Our findings confirm that hormones can explain significant amounts of variation in contributions to offspring feeding, and that cortisol, not prolactin, is the hormone most strongly associated with pup-feeding in cooperative male meerkats.

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Corbacho, AM, G. Martinez De La Escalera, and C. Clapp. "Roles of prolactin and related members of the prolactin/growth hormone/placental lactogen family in angiogenesis." Journal of Endocrinology 173, no. 2 (May 1, 2002): 219–38. http://dx.doi.org/10.1677/joe.0.1730219.

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Prolactin, growth hormone and placental lactogen are members of a family of polypeptide hormones which share structural similarities and biological activities. Numerous functions have been attributed to these hormones, among which stand out their recently discovered effects on angiogenesis, the process by which new blood vessels are formed from the pre-existing microvasculature. Prolactin, growth hormone and placental lactogen, along with two non-classical members of the family, proliferin and proliferin-related protein, can act both as circulating hormones and as paracrine/autocrine factors to either stimulate or inhibit various stages of the formation and remodeling of new blood vessels, including endothelial cell proliferation, migration, protease production and apoptosis. Such opposing actions can reside in similar but independent molecules, as is the case of proliferin and proliferin-related protein, which stimulate and inhibit angiogenesis respectively. The potential to exert opposing effects on angiogenesis can also reside within the same molecule as the parent protein can promote angiogenesis (i.e. prolactin, growth hormone and placental lactogen), but after proteolytic processing the resulting peptide fragment acquires anti-angiogenic properties (i.e. 16 kDa prolactin, 16 kDa growth hormone and 16 kDa placental lactogen). The unique properties of the peptide fragments versus the full-length molecules, the regulation of the protease responsible for specific protein cleavage, the selective expression of specific receptors and their associated signal transduction pathways are issues that are being investigated to further establish the precise contribution of these hormones to angiogenesis under both physiological and pathological situations. In this review article, we summarize the known and speculative issues underlying the effects of the prolactin, growth hormone and placental lactogen family of proteins on angiogenesis, and address important remaining enigmas in this field of research.

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Miki, Yasuhiro, Erina Iwabuchi, Katsuhiko Ono, Hironobu Sasano, and Kiyoshi Ito. "Exploring Protein–Protein Interaction in the Study of Hormone-Dependent Cancers." International Journal of Molecular Sciences 19, no. 10 (October 15, 2018): 3173. http://dx.doi.org/10.3390/ijms19103173.

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Estrogen receptors promote target gene transcription when they form a dimer, in which two identical (homodimer) or different (heterodimer) proteins are bound to each other. In hormone-dependent cancers, hormone receptor dimerization plays pivotal roles, not only in the pathogenesis or development of the tumors, but also in the development of therapeutic resistance. Protein–protein interactions (PPIs), including dimerization and complex formation, have been also well-known to be required for proteins to exert their functions. The methods which could detect PPIs are genetic engineering (i.e., resonance energy transfer) and/or antibody technology (i.e., co-immunoprecipitation) using cultured cells. In addition, visualization of the target proteins in tissues can be performed using antigen–antibody reactions, as in immunohistochemistry. Furthermore, development of microscopic techniques (i.e., electron microscopy and confocal laser microscopy) has made it possible to visualize intracellular and/or intranuclear organelles. We have recently reported the visualization of estrogen receptor dimers in breast cancer tissues by using the in situ proximity ligation assay (PLA). PLA was developed along the lines of antibody technology development, and this assay has made it possible to visualize PPIs in archival tissue specimens. Localization of PPI in organelles has also become possible using super-resolution microscopes exceeding the resolution limit of conventional microscopes. Therefore, in this review, we summarize the methodologies used for studying PPIs in both cells and tissues, and review the recently reported studies on PPIs of hormones.

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Meier, V. S., and B. Groner. "The nuclear factor YY1 participates in repression of the beta-casein gene promoter in mammary epithelial cells and is counteracted by mammary gland factor during lactogenic hormone induction." Molecular and Cellular Biology 14, no. 1 (January 1994): 128–37. http://dx.doi.org/10.1128/mcb.14.1.128.

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Expression of the beta-casein milk protein gene in the mammary epithelial cell line HC11 is primarily regulated at the transcriptional level. A 338-bp segment of promoter sequence 5' of the transcription start site is sufficient to confer inducibility by the lactogenic hormones insulin, glucocorticoid hormone, and prolactin. Positively and negatively acting promoter elements and specific DNA binding proteins have been identified. The binding of the mammary gland factor MGF to a site between -80 and -100 is indispensable for hormonal induction of transcription. Binding of MGF activity to DNA is greatly enhanced by the action of the lactogenic hormones. Repression of transcription in the uninduced state is mediated by a promoter element located adjacent to the MGF binding site at positions -110 to -150. This repressor element consists of two interacting protein binding sites. A nuclear factor that binds specifically to the proximal site between positions -110 and -120 has been characterized and found to be identical with the nuclear factor YY1 (delta, NF-E1). YY1 does not bind to the distal site. The simultaneous mutation in the proximal and the distal sites results in high, hormone-independent transcription. This finding suggests that YY1 plays a functional role in the repression and acts in conjunction with a second DNA binding protein. Comparison of YY1 DNA binding activity in uninduced and hormone-induced cells showed that relief of repression is not mediated by changes in the concentration or binding affinity of YY1. Infection of HC11 cells with a YY1-expressing recombinant retrovirus resulted in overexpression of YY1 but did not suppress hormonal induction. The addition of purified MGF decreased YY1 binding to its DNA recognition site in vitro. This finding indicates that MGF regulates the DNA binding activity of YY1 and thereby may cause the relief of transcriptional repression.

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Meier, V. S., and B. Groner. "The nuclear factor YY1 participates in repression of the beta-casein gene promoter in mammary epithelial cells and is counteracted by mammary gland factor during lactogenic hormone induction." Molecular and Cellular Biology 14, no. 1 (January 1994): 128–37. http://dx.doi.org/10.1128/mcb.14.1.128-137.1994.

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Expression of the beta-casein milk protein gene in the mammary epithelial cell line HC11 is primarily regulated at the transcriptional level. A 338-bp segment of promoter sequence 5' of the transcription start site is sufficient to confer inducibility by the lactogenic hormones insulin, glucocorticoid hormone, and prolactin. Positively and negatively acting promoter elements and specific DNA binding proteins have been identified. The binding of the mammary gland factor MGF to a site between -80 and -100 is indispensable for hormonal induction of transcription. Binding of MGF activity to DNA is greatly enhanced by the action of the lactogenic hormones. Repression of transcription in the uninduced state is mediated by a promoter element located adjacent to the MGF binding site at positions -110 to -150. This repressor element consists of two interacting protein binding sites. A nuclear factor that binds specifically to the proximal site between positions -110 and -120 has been characterized and found to be identical with the nuclear factor YY1 (delta, NF-E1). YY1 does not bind to the distal site. The simultaneous mutation in the proximal and the distal sites results in high, hormone-independent transcription. This finding suggests that YY1 plays a functional role in the repression and acts in conjunction with a second DNA binding protein. Comparison of YY1 DNA binding activity in uninduced and hormone-induced cells showed that relief of repression is not mediated by changes in the concentration or binding affinity of YY1. Infection of HC11 cells with a YY1-expressing recombinant retrovirus resulted in overexpression of YY1 but did not suppress hormonal induction. The addition of purified MGF decreased YY1 binding to its DNA recognition site in vitro. This finding indicates that MGF regulates the DNA binding activity of YY1 and thereby may cause the relief of transcriptional repression.

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Copping, Susan, and Peter G. H. Byfield. "The role of thyroid hormone autoantibodies in serum transport." Acta Endocrinologica 121, no. 4 (October 1989): 551–59. http://dx.doi.org/10.1530/acta.0.1210551.

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Abstract. Eleven sera known to contain thyroid hormone autoantibodies were analysed by reverse-flow electrophoresis for the equilibrium distribution of thyroid hormones between these autoantibodies and the three normal binding proteins found in serum. The binding properties of the autoantibodies determined in vitro did not necessarily predict their contribution to transport in serum of T4 and T3. Some could both bind in vitro and transport in serum. Others were able to bind both hormones but transported only one. However, some autoantibodies could be specific, binding and transporting one hormone only. In some sera, the autoantibody was the dominant transport protein having drawn hormone from thyroxine-binding globulin which is normally the most important. The autoantibodies were not saturated even in euthyroid individuals, indicating that they bind hormone reversibly and are a part of an equilibrium system.

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Somogyi, Virág, Tamás L. Horváth, István Tóth, Tibor Bartha, László Vilmos Frenyó, Dávid Sándor Kiss, Gergely Jócsák, Annamária Kerti, Frederick Naftolin, and Attila Zsarnovszky. "Bisphenol A influences oestrogen- and thyroid hormone-regulated thyroid hormone receptor expression in rat cerebellar cell culture." Acta Veterinaria Hungarica 64, no. 4 (December 2016): 497–513. http://dx.doi.org/10.1556/004.2016.046.

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Thyroid hormones (THs) and oestrogens are crucial in the regulation of cerebellar development. TH receptors (TRs) mediate these hormone effects and are regulated by both hormone families. We reported earlier that THs and oestradiol (E2) determine TR levels in cerebellar cell culture. Here we demonstrate the effects of low concentrations (10–10 M) of the endocrine disruptor (ED) bisphenol A (BPA) on the hormonal (THs, E2) regulation of TRα,β in rat cerebellar cell culture. Primary cerebellar cell cultures, glia-containing and glia-destroyed, were treated with BPA or a combination of BPA and E2 and/or THs. Oestrogen receptor and TH receptor mRNA and protein levels were determined by real-time qPCR and Western blot techniques. The results show that BPA alone decreases, while BPA in combination with THs and/or E2 increases TR mRNA expression. In contrast, BPA alone increased receptor protein expressions, but did not further increase them in combination with THs and/or E2. The modulatory effects of BPA were mediated by the glia; however, the degree of changes also depended on the specific hormone ligand used. The results signify the importance of the regulatory mechanisms interposed between transcription and translation and raise the possibility that BPA could act to influence nuclear hormone receptor levels independently of ligand–receptor interaction.

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Kinney, Christian J., and Robert J. Bloch. "µ-Crystallin: A thyroid hormone binding protein." Endocrine Regulations 55, no. 2 (April 1, 2021): 89–102. http://dx.doi.org/10.2478/enr-2021-0011.

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Abstract µ-Crystallin is a NADPH-regulated thyroid hormone binding protein encoded by the CRYM gene in humans. It is primarily expressed in the brain, muscle, prostate, and kidney, where it binds thyroid hormones, which regulate metabolism and thermogenesis. It also acts as a ketimine reductase in the lysine degradation pathway when it is not bound to thyroid hormone. Mutations in CRYM can result in non-syndromic deafness, while its aberrant expression, predominantly in the brain but also in other tissues, has been associated with psychiatric, neuromuscular, and inflammatory diseases. CRYM expression is highly variable in human skeletal muscle, with 15% of individuals expressing ≥13 fold more CRYM mRNA than the median level. Ablation of the Crym gene in murine models results in the hypertrophy of fast twitch muscle fibers and an increase in fat mass of mice fed a high fat diet. Overexpression of Crym in mice causes a shift in energy utilization away from glycolysis towards an increase in the catabolism of fat via β-oxidation, with commensurate changes of metabolically involved transcripts and proteins. The history, attributes, functions, and diseases associated with CRYM, an important modulator of metabolism, are reviewed.

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Luo, H., R. P. Lindeman, and H. S. Chase. "Participation of protein kinase C in desensitization to bradykinin and to carbachol in MDCK cells." American Journal of Physiology-Renal Physiology 262, no. 3 (March 1, 1992): F499—F506. http://dx.doi.org/10.1152/ajprenal.1992.262.3.f499.

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To explore the possibility that protein kinase C (PKC) participates in desensitization to Ca(2+)-mobilizing hormones in MDCK cells, we measured intracellular free Ca2+ concentration ([Ca2+]i) using fura-2 and video microscopy. We first examined the response of MDCK cells grown on plastic dishes. Exposure of cells to bradykinin (BK) or to carbachol, followed by reexposure after washing off the hormone, revealed two features of hormone desensitization. First, the initial hormone-induced peak response of [Ca2+]i was transitory; [Ca2+]i returned to control levels despite continued presence of hormone. Second, cells remained refractory to hormone rechallenge for 5 min after washing off hormone; [Ca2+]i response on re-exposure was reduced 70% compared with initial hormone-stimulated peak. Subsequent experiments demonstrated involvement of PKC in both desensitization processes. Pretreatment with the phorbol ester, phorbol 12-myristate 13-acetate, significantly blunted initial response to BK and to carbachol by 70 and 86%, respectively. When hormone-stimulated C kinase activity was enhanced with the diglyceride lipase inhibitor, RG 80267, BK- and carbachol-induced increases in [Ca2+]i were blunted 50%. Pretreatment with sphingosine, an inhibitor of PKC, resulted in an amplification of initial hormone-stimulated increase in [Ca2+]i and restored the response to rechallenge. To examine the possible interaction between BK and carbachol,both of which use PKC to induce desensitization, we measured [Ca2+]i in cells grown as monolayers on permeable, collagen-coated supports. Both carbachol and BK induced desensitization to the other hormone (heterologous desensitization)provided that the two hormones were applied to the same side of the polarized monolayer (apical).(ABSTRACT TRUNCATED AT 250 WORDS)

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Chestnut, RE, WS Prince, V. Quarmby, M. Reichert, and WL Wong. "Adaptation of the growth hormone binding protein LIFA for detection of growth hormone: Growth hormone binding protein complexes." Growth Hormone & IGF Research 8, no. 4 (August 1998): 334. http://dx.doi.org/10.1016/s1096-6374(98)80220-7.

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Moore, H. P., and R. B. Kelly. "Secretory protein targeting in a pituitary cell line: differential transport of foreign secretory proteins to distinct secretory pathways." Journal of Cell Biology 101, no. 5 (November 1, 1985): 1773–81. http://dx.doi.org/10.1083/jcb.101.5.1773.

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The mouse pituitary cell line, AtT-20, packages the adrenocorticotropic hormone (ACTH) in secretory vesicles and releases it when the cell is stimulated with secretagogues. These cells have the capacity, after transfection with the appropriate DNA, to package heterologous peptide hormones into the regulated secretory vesicles (Moore, H. P. H., M. D. Walker, F. Lee, and R. B. Kelly, 1983, Cell, 35:531-538). To test if other secreted proteins prefer a different route to the surface, we have transfected AtT-20 cells with DNAs coding for a fragment of a membrane protein, the vesicular stomatitis virus G protein from which the membrane spanning domain has been deleted (Rose, J. K., and J. E. Bergmann, 1982, Cell, 17:813-819). We found that the secreted vesicular stomatitis virus G proteins were not transported to the regulated secretory vesicles. Instead they preferentially exited the cell by the constitutive pathway previously found in these cells (Gumbiner, B., and R. B. Kelly, 1982, Cell, 28:51-59). In contrast, human growth hormone transfected into the cells by the same procedure was transported to the regulated pathway with a similar efficiency as the endogenous hormone ACTH. Transport of the secreted G protein to the regulated pathway, if it occurs at all, is at least 30-fold less efficient than peptide hormones. We conclude that the transport machinery in AtT-20 cells must selectively recognize different secreted proteins and sort them into distinct secretory pathways.

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Pombo, Celia M., Juan Zalvide, Bruce D. Gaylinn, and Carlos Diéguez. "Growth Hormone-Releasing Hormone Stimulates Mitogen-Activated Protein Kinase*." Endocrinology 141, no. 6 (June 1, 2000): 2113–19. http://dx.doi.org/10.1210/endo.141.6.7513.

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30

Muff, Roman, Walter Born, Margit Kaufmann, and Jan A. Fischer. "Parathyroid hormone and parathyroid hormone-related protein receptor update." Molecular and Cellular Endocrinology 100, no. 1-2 (April 1994): 35–38. http://dx.doi.org/10.1016/0303-7207(94)90275-5.

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31

Branvold, D. J., D. R. Allred, D. J. Beckstead, H. J. Kim, N. Fillmore, B. M. Condon, J. D. Brown, S. N. Sudweeks, D. M. Thomson, and W. W. Winder. "Thyroid hormone effects on LKB1, MO25, phospho-AMPK, phospho-CREB, and PGC-1α in rat muscle." Journal of Applied Physiology 105, no. 4 (October 2008): 1218–27. http://dx.doi.org/10.1152/japplphysiol.00997.2007.

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Expression of all of the isoforms of the subunits of AMP-activated protein kinase (AMPK) and AMPK activity is increased in skeletal muscle of hyperthyroid rats. Activity of AMPK in skeletal muscle is regulated principally by the upstream kinase, LKB1. This experiment was designed to determine whether the increase in AMPK activity is accompanied by increased expression of the LKB1, along with binding partner proteins. LKB1, MO25, and downstream targets were determined in muscle extracts in control rats, in rats given 3 mg of thyroxine and 1 mg of triiodothyronine per kilogram chow for 4 wk, and in rats given 0.01% propylthiouracil (PTU; an inhibitor of thyroid hormone synthesis) in drinking water for 4 wk (hypothyroid group). LKB1 and MO25 increased in the soleus of thyroid hormone-treated rats vs. the controls. In other muscle types, LKB1 responses were variable, but MO25 increased in all. In soleus, MO25 mRNA increased with thyroid hormone treatment, and STRAD mRNA increased with PTU treatment. Phospho-AMPK and phospho-ACC were elevated in soleus and gastrocnemius of hyperthyroid rats. Thyroid hormone treatment also increased the amount of phospho-cAMP response element binding protein (CREB) in the soleus, heart, and red quadriceps. Four proteins having CREB response elements (CRE) in promoter regions of their genes (peroxisome proliferator-activated receptor-γ coactivator-1α, uncoupling protein 3, cytochrome c, and hexokinase II) were all increased in soleus in response to thyroid hormones. These data provide evidence that thyroid hormones increase soleus muscle LKB1 and MO25 content with subsequent activation of AMPK, phosphorylation of CREB, and expression of mitochondrial protein genes having CRE in their promoters.

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32

Guyansyah, Assangga, and ML Edy Parwanto. "Protein pengikat hormon seks: sex hormone binding globulin (SHBG) dan aksi steroid seks." Jurnal Biomedika dan Kesehatan 2, no. 1 (March 31, 2019): 45–50. http://dx.doi.org/10.18051/jbiomedkes.2019.v2.45-50.

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Jumlah gen pada manusia sekitar 30 000 gen, salah satunya yaitu gen SHBG (sex hormone binding globulin). Telah terbukti bahwa protein merupakan produk gen. Gen yang diekspresikan berarti mengkode sintesis protein. Pada studi ini mempelajari tentang protein sex hormone binding globulin (SHBG) yang merupakan produk gen SHBG. Gen SHBG terletak pada kromosom 17 p 3.1 di setiap sel tubuh kita. Gen SHBG pada hepatosit mengkode protein SHBG, protein tersebut selanjutnya disekresikan ke sistem sirkulasi. Gen SHBG di dalam hepatosit memiliki kesamaan dengan gen androgen binding protein (ABP) di sel Sertoli dalam testis. Jumlah gen pada manusia sekitar 30 000 gen, salah satunya yaitu gen SHBG (sex hormone binding globulin). Telah terbukti bahwa protein merupakan produk gen. Gen yang diekspresikan berarti mengkode sintesis protein. Pada studi ini mempelajari tentang protein sex hormone binding globulin (SHBG) yang merupakan produk gen SHBG. Gen SHBG terletak pada kromosom 17 p 3.1 di setiap sel tubuh kita. Gen SHBG pada hepatosit mengkode protein SHBG, protein tersebut selanjutnya disekresikan ke sistem sirkulasi. Gen SHBG di dalam hepatosit memiliki kesamaan dengan gen androgen binding protein (ABP) di sel Sertoli dalam testis. Dalam sisntesis protein SHBG maupun ABP ada 2 tahap yaitu tahap sintesis prekursor protein dan tahap selanjutnya pematangan prekursor protein di badan Golgi dengan proses glikosilasi. Protein SHBG maupun ABP memiliki funsgi sama yaitu memperantarai aksi hormon steroid seks ke sel sasaran. Ikatan antara SHBG dengan steroid tersebut bersifat reversibel dan berafinitas tinggi untuk mengikat androgen (dehidrotestosteron/DHT, testosteron, 3α-androstenediol), sedangkan ikatan terhadap estrogen aktif maupun estradiol dengan afinitas yang lebih rendah. Aksi steroid seks ke sel sasaran telah terbukti dengan 2 cara yaitu cara pertama dengan berdifusi melewati membran sel sasaran dan cara kedua dengan sistem transduksi sinyal yang diperantarai oleh reseptor SHBG (R-SHBG) pada permukaan sel sasaran. Protein SHBG di dalam sistem sirkulasi memiliki fungsi untuk mengikat hormon steroid seks dan memperantarai aksi hormon tersebut ke sel sasaran di luar testis, sedangkan ABP berfungsi memperantarai aksi hormon steroid seks di dalam testis.

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33

Strewler, Gordon J. "THE PARATHYROID HORMONE–RELATED PROTEIN." Endocrinology and Metabolism Clinics of North America 29, no. 3 (September 2000): 629–45. http://dx.doi.org/10.1016/s0889-8529(05)70154-7.

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34

Souberbielle, Jean-Claude. "Parathyroid hormone related protein (PTHrP)." EMC - Biologie Médicale 1, no. 1 (January 2006): 1–3. http://dx.doi.org/10.1016/s2211-9698(06)76102-7.

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35

Seth, John. "Standardization of Protein Hormone Immunoassays." Annals of Clinical Biochemistry: International Journal of Laboratory Medicine 33, no. 6 (November 1996): 482–85. http://dx.doi.org/10.1177/000456329603300602.

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36

Salomon, Franco, Ross Cuneo, and Peter H. Sönkse. "Growth Hormone and Protein Metabolism." Hormone Research 36, no. 1 (1991): 41–43. http://dx.doi.org/10.1159/000182187.

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37

Moller, Niels, Mikkel H. Vendelbo, Ulla Kampmann, Britt Christensen, Michael Madsen, Helene Norrelund, and Jens O. Jorgensen. "Growth hormone and protein metabolism." Clinical Nutrition 28, no. 6 (December 2009): 597–603. http://dx.doi.org/10.1016/j.clnu.2009.08.015.

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38

Althumairy, Duaa, Xiaoping Zhang, Nicholas Baez, George Barisas, Deborah A. Roess, George R. Bousfield, and Debbie C. Crans. "Glycoprotein G-protein Coupled Receptors in Disease: Luteinizing Hormone Receptors and Follicle Stimulating Hormone Receptors." Diseases 8, no. 3 (September 15, 2020): 35. http://dx.doi.org/10.3390/diseases8030035.

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Signal transduction by luteinizing hormone receptors (LHRs) and follicle-stimulating hormone receptors (FSHRs) is essential for the successful reproduction of human beings. Both receptors and the thyroid-stimulating hormone receptor are members of a subset of G-protein coupled receptors (GPCRs) described as the glycoprotein hormone receptors. Their ligands, follicle-stimulating hormone (FSH) and luteinizing hormone (LH) and a structurally related hormone produced in pregnancy, human chorionic gonadotropin (hCG), are large protein hormones that are extensively glycosylated. Although the primary physiologic functions of these receptors are in ovarian function and maintenance of pregnancy in human females and spermatogenesis in males, there are reports of LHRs or FSHRs involvement in disease processes both in the reproductive system and elsewhere. In this review, we evaluate the aggregation state of the structure of actively signaling LHRs or FSHRs, their functions in reproduction as well as summarizing disease processes related to receptor mutations affecting receptor function or expression in reproductive and non-reproductive tissues. We will also present novel strategies for either increasing or reducing the activity of LHRs signaling. Such approaches to modify signaling by glycoprotein receptors may prove advantageous in treating diseases relating to LHRs or FSHRs function in addition to furthering the identification of new strategies for modulating GPCR signaling.

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39

Tena-Sempere, Manuel, and Ilpo Huhtaniemi. "Sex in the brain: How the brain regulates reproductive function." Biochemist 31, no. 2 (April 1, 2009): 4–7. http://dx.doi.org/10.1042/bio03102004.

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Reproductive functions are maintained by a complex hormonal regulatory network called the hypothalamic–pituitary–gonadal (HPG) axis, which is under the hierarchical control of a network of neurohormones that ultimately modulate the synthesis and pulsatile release of the decapeptide gonadotropin-releasing hormone (GnRH) by specialized neural cells distributed along the mediobasal hypothalamus. This neuropeptide drives the production of the two gonadotropic hormones of the anterior pituitary gland, luteinizing hormone (LH) and folliclestimulating hormone (FSH), which are released into the circulation and regulate specific functions of the ovary and testis. In turn, hormones produced by the gonads feed back to the hypothalamic– pituitary level to maintain functional balance of the HPG axis, through negative and positive (only in females) regulatory loops. In this article, we review the main hormonal regulatory systems that are operative in the HPG axis with special emphasis on recent developments in our knowledge of the neuroendocrine pathways governing GnRH secretion, including the identification of kisspeptins and G-protein-coupled receptor 54 (GPR54) as major gatekeepers of puberty onset and fertility.

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40

Negrev, Negrin, Yuri Nyagolov, Margarita Stefanova, and Emiliya Stancheva. "Thyroid hormonal axis regulates protein C anticoagulation pathway in rats." Open Life Sciences 6, no. 4 (August 1, 2011): 518–23. http://dx.doi.org/10.2478/s11535-011-0031-y.

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AbstractEffects of the hormones of the hypothalamic-pituitary-thyroid axis on some basic parameters of the activity of protein C anticoagulation pathway in rats are studied. Thyrotropin-releasing hormone (0.06 mg/kg body mass), thyrotropin (1 IU/kg), triiodothyronine (T3) (0.08 mg/kg), thyroxine (T4) (0.08 mg/kg), administered subcutaneously for three consecutive days on four different groups of rats increased significantly activated protein C, free protein S and protein S activity, and reduced the soluble endothelial protein C receptor. Protein C antigen and total protein S were significantly elevated only by thyrotropin-releasing hormone and thyroid-stimulating hormone, but they were not affected by T3 and T4 treatment. The data indicate the hypothalamic-pituitary-thyroid axis is involved in the regulation of the protein C anticoagulation pathway in rats by activation of this system, suggesting a tendency of hypocoagulability.

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41

TAKAHASHI, Shin-Ichirou. "Hormone and protein metabolism. Insulin and protein metabolism." Journal of the agricultural chemical society of Japan 61, no. 10 (1987): 1300–1304. http://dx.doi.org/10.1271/nogeikagaku1924.61.1300.

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42

KATO, Shigeaki. "Hormone and protein metabolism. Glucocorticoid and protein metabolism." Journal of the agricultural chemical society of Japan 61, no. 10 (1987): 1309–11. http://dx.doi.org/10.1271/nogeikagaku1924.61.1309.

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TAKENAKA, Akio. "Hormone and protein metabolism. Glucagon and protein metabolism." Journal of the agricultural chemical society of Japan 61, no. 10 (1987): 1312–14. http://dx.doi.org/10.1271/nogeikagaku1924.61.1312.

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44

YAGASAKI, Kazumi. "Hormone and protein metabolism. Prostaglandin and protein metabolism." Journal of the agricultural chemical society of Japan 61, no. 10 (1987): 1315–18. http://dx.doi.org/10.1271/nogeikagaku1924.61.1315.

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45

Mobbs, C., G. Fink, M. Johnson, W. Welch, and D. Pfaff. "Similarity of an estrogen-induced protein and a luteinizing hormone releasing hormone-induced protein." Molecular and Cellular Endocrinology 62, no. 2 (April 1989): 297–306. http://dx.doi.org/10.1016/0303-7207(89)90017-8.

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46

Craig, Elaine E., Alan Chesley, and David A. Hood. "Thyroid hormone modifies mitochondrial phenotype by increasing protein import without altering degradation." American Journal of Physiology-Cell Physiology 275, no. 6 (December 1, 1998): C1508—C1515. http://dx.doi.org/10.1152/ajpcell.1998.275.6.c1508.

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The mitochondrial phenotype within cardiac muscle cells is dramatically altered by thyroid hormone. We report here that this can be accounted for, in part, by modifications in the rate of mitochondrial protein import. The import of matrix-localized precursor proteins malate dehydrogenase (MDH) and ornithine carbamoyltransferase was augmented, whereas the insertion of the outer membrane protein Bcl-2 was unaffected by thyroid hormone treatment. Coincident with increases in the import of these matrix-localized precursors were thyroid hormone-induced elevations in the outer membrane receptor Tom20 and the matrix heat-shock protein mthsp70. The phospholipid cardiolipin was not involved in mediating the thyroid hormone-induced increase in import, as judged from adriamycin inhibition studies. When the import reaction was supplemented with rat heart cytosol, we found that 1) MDH import was stimulated, but Bcl-2 import was inhibited and 2) thyroid hormone did not influence the effect of the cytosol on import rates. Thus distinct requirements exist for the mitochondrial import of precursor proteins, destined for different organellar compartments. Although import of these matrix-localized proteins was augmented by thyroid hormone treatment, the proteolysis of matrix proteins was unaffected as indicated by the degradation of cytob2(167)RIC-dihydrofolate reductase, a chimeric protein missorted to the matrix. Thus our data indicate that at least some thyroid hormone-induced modifications of the mitochondrial phenotype occur due to the compartment-specific upregulation of precursor protein import rates, likely mediated via changes in the expression of protein import machinery components.

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Kharrazian, Datis, Martha Herbert, and Aristo Vojdani. "Immunological Reactivity Using Monoclonal and Polyclonal Antibodies of Autoimmune Thyroid Target Sites with Dietary Proteins." Journal of Thyroid Research 2017 (2017): 1–13. http://dx.doi.org/10.1155/2017/4354723.

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Many hypothyroid and autoimmune thyroid patients experience reactions with specific foods. Additionally, food interactions may play a role in a subset of individuals who have difficulty finding a suitable thyroid hormone dosage. Our study was designed to investigate the potential role of dietary protein immune reactivity with thyroid hormones and thyroid axis target sites. We identified immune reactivity between dietary proteins and target sites on the thyroid axis that includes thyroid hormones, thyroid receptors, enzymes, and transport proteins. We also measured immune reactivity of either target specific monoclonal or polyclonal antibodies for thyroid-stimulating hormone (TSH) receptor, 5′deiodinase, thyroid peroxidase, thyroglobulin, thyroxine-binding globulin, thyroxine, and triiodothyronine against 204 purified dietary proteins commonly consumed in cooked and raw forms. Dietary protein determinants included unmodified (raw) and modified (cooked and roasted) foods, herbs, spices, food gums, brewed beverages, and additives. There were no dietary protein immune reactions with TSH receptor, thyroid peroxidase, and thyroxine-binding globulin. However, specific antigen-antibody immune reactivity was identified with several purified food proteins with triiodothyronine, thyroxine, thyroglobulin, and 5′deiodinase. Laboratory analysis of immunological cross-reactivity between thyroid target sites and dietary proteins is the initial step necessary in determining whether dietary proteins may play a potential immunoreactive role in autoimmune thyroid disease.

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Webb, C. F., and M. Wallis. "A comparison of lactogenic receptors from rat liver and Nb2 rat lymphoma cells by using cross-linking techniques." Biochemical Journal 250, no. 1 (February 15, 1988): 215–19. http://dx.doi.org/10.1042/bj2500215.

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Lactogenic receptors were analysed with the use of the cross-linking agent disuccinimidyl suberate to attach covalently 125I-labelled ovine prolactin or human growth hormone to binding sites from (1) liver from pregnant rats and (2) the rat-derived Nb2 lymphoma cell line. Analysis by SDS/polyacrylamide-gel electrophoresis of the proteins cross-linked to labelled hormone in rat liver indicated a major specifically-labelled complex with an Mr of 68,000-72,000, when run under reducing or non-reducing conditions. With Nb2 cells a major specifically-labelled complex with an Mr of 97,000-110,000 was identified, but only when electrophoresis was run using reducing conditions. Assuming one hormone molecule (Mr 22,000-24,000) per hormone-receptor complex, then the receptor proteins have an Mr of 44,000-50,000 for rat liver and 73,000-88,000 for the Nb2 cells. For both cell types the receptors were of lactogenic specificity; lactogenic hormones competed for binding whereas somatogenic hormones did not. These studies suggest that the lactogenic receptors in rat liver membranes and Nb2 cells differ in two respects. Firstly, the Mr of the labelled receptor protein in Nb2 cells is greater than that of the corresponding receptor protein in rat liver membranes; secondly, the Nb2 cell receptor appears to exist as a disulphide-linked oligomer whereas the receptor in rat liver membranes does not.

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Leung, Peter C. K., Jian Wang, and Kenneth G. Baimbridge. "Mechanism of action of luteinizing hormone-releasing hormone in rat ovarian cells." Canadian Journal of Physiology and Pharmacology 67, no. 8 (August 1, 1989): 962–67. http://dx.doi.org/10.1139/y89-152.

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The initial step in the signal transduction of luteinizing hormone-releasing hormone (LHRH) in rat ovarian cells is the hydrolysis of membrane polyphosphoinositides into inositol phosphates and 1,2-diacylglycerol. The former compounds, especially inositol 1,4,5-triphosphate, are known to cause the release of calcium from intracellular stores, while diacylglycerol is a potent activator of protein kinase C. LHRH causes a rapid and transient increase in intracellular concentrations of free calcium ions, by approximately 4.5-fold, in the majority of granulosa cells as assessed by fura-2 microspectrofluorimetry. Like LHRH, a calcium ionophore (A23187) and activators of protein kinase C attenuate the steroidogenic response of the cells to follicle-stimulating hormone, but enhance the formation of gonadotropin-induced prostaglandin formation. These results support the concept that stimulation of polyphosphoinositide hydrolysis is intimitely involved in the direct action of LHRH at the level of the ovary.Key words: signal transduction, calcium, protein kinase C, ovary, steroid hormones.

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50

Starkov, A. A. "“Mild” Uncoupling of Mitochondria." Bioscience Reports 17, no. 3 (June 1, 1997): 273–79. http://dx.doi.org/10.1023/a:1027380527769.

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Recently, it was proposed that the thyroid hormone-mediated uncoupling in mitochondria is involved in the cellular defence system against free radicals (Skulachev V.P. (1996) Quart. Rev. Biophys. 29:169–202). This phenomenon was named “mild” uncoupling. It was postulated to be a protein-mediated process controlled by several factors. The data reported during the past 40 years, pointing to the protein-mediated uncoupling mechanism in mitochondria, are reviewed in a context of hypothetical properties of “mild” uncoupling. The mechanism of “mild” uncoupling is suggested to be the following: (a) mitochondria possess protein(s) that regulate the proton permeability of inner mitochondrial membrane; (b) these proteins are regulated by binding of an unidentified low-molecular-weight endogenous compound with properties resembling those of the most active artificial uncouplers like FCCP and SF6847; (c) the interaction of this compound with its target protein(s) is modulated by a thyroid hormone in a positive (i.e. enhancing the proton permeability) way and by sex steroid hormones in a negative way; (e) endogenous fatty acids can attenuate the influence of both thyroid and steroid hormones.

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Journal articles on the topic 'Protein hormone'

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