Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P56851 (epididymal)
 11,273 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Principal cells of the mouse caput epididymidis synthesize and secrete a 24 kDa protein able to bind to the head of the spermatozoa. Sequencing of several clones selected from cDNA and genomic libraries, combined with the microsequencing of the NH2 terminus of the protein allowed to reconstitute the entire primary structure of the mature 24 kDa protein. It revealed 81% homology with a human plasma glutathione peroxidase and 61% homology with a mouse erythrocyte glutathione peroxidase. This enzyme, once secreted in the epididymal fluid, might protect sperm membrane lipids, particularly those of the acrosomal part, against peroxidation.
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PMID:[Androgen-dependent protein secreted by mouse caput epididymis shows high homologies with different glutathione peroxidases]. 191 44

Bovine spermatozoa that have been exposed to seminal plasma possess more binding sites for heparin than sperm from the cauda epididymis that have not been exposed to accessory sex gland secretions. Seminal plasma exposure enables sperm, following incubation with heparin, to undergo zonae pellucidae-induced exocytosis of the acrosome. In this study, the regulatory role of seminal plasma heparin-binding proteins in capacitation of bovine spermatozoa by heparin was investigated. Plasma membranes from sperm exposed to seminal plasma in vivo or in vitro contained a series of acidic 15-17 kDa proteins not found in cauda epididymal sperm. Western blots of membrane proteins indicated that these 15-17 kDa proteins bound [125I]-heparin. Heparin-binding proteins were isolated by heparin affinity chromatography from seminal plasma from vasectomized bulls. Gel electrophoresis indicated that the heparin-binding peaks contained 14-18 kDa proteins with isoelectric variation, a basic 24 kDa protein, and a 31 kDa protein. Western blots probed with [125I]-heparin confirmed the ability of each of these proteins to bind heparin. Each of these proteins, as well as control proteins, bound to epididymal sperm. The seminal plasma proteins were peripherally associated with sperm since they were removed by hypertonic medium and did not segregate into the detergent phase of Triton X-114. Seminal plasma heparin-binding proteins potentiated zonae pellucidae-induced acrosome reactions in epididymal sperm. However, seminal plasma proteins that did not bind to the heparin affinity column were unable to stimulate zonae-sensitivity. Control proteins, including lysozyme--which binds to both heparin and sperm, were ineffective at enhancing zonae-induced acrosome reactions. These data provide evidence for a positive regulatory role of seminal plasma heparin-binding proteins in capacitation of bovine spermatozoa.
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PMID:Heparin-binding proteins from seminal plasma bind to bovine spermatozoa and modulate capacitation by heparin. 238 14

Two peptides with a molecular weight of 24 kDa and a P(i) of 8.4-8.8 were found to be synthesized and secreted specifically by the caput epididymis of adult male mice under androgen control. The peptides can interact with spermatozoa. In the present study, the developmental pattern of [35S]-methionine-labelled proteins synthesized by the murine caput epididymis at 10, 20, 30 and 40 days of age were studied using two-dimensional polyacrylamide gel electrophoresis (2D PAGE) and autoradiography. Active synthesis of the 24 kDa proteins was detected in the epididymis from 20 days of age, but secretion of the two peptides was only observed from 30 days of age onwards. To determine whether androgens influenced the active expression of 24 kDa proteins in the developing epididymis, their effect on [35S]-methionine incorporation into proteins was assessed using 2D PAGE. Mice were either castrated, castrated then testosterone injected or simply testosterone injected at 10, 20, 30 or 40 days of age. Androgen control of 24 kDa protein expression was also studies in vitro in epididymal organ culture over a 10-day period, with or without testosterone. Androgens were not involved in the initiation of synthesis of the 24 kDa proteins from days 10 to 20, as shown by in-vivo and in-vivo experiments. However, androgens appeared to be essential for maintaining synthesis and secretion of the proteins from 20 days of age onwards. Administration of excessive testosterone was only able to increase secretion of the 24 kDa proteins in intact male mice aged 40 days.
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PMID:Developmental expression and androgen regulation of 24 kDa secretory proteins by the murine epididymis. 851 27