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)

A monoclonal antibody (MAb) raised against human sperm protein, designated YWK-II, was used to determine the distribution of antigens in rat spermatozoa and rat testicular germ cells. By an indirect immunofluorescent method, the antibody localized over the rat spermatozoal head, except for the postacrosomal region. In paraffin sections of adult and immature rat testis, germ cells, at every developmental stage, and Sertoli cells stained, while interstitial cells and peritubular myoid cells remained unstained. When cocultures of Sertoli and germ cells were tested, only the germ cells stained intensely. Sertoli cells and peritubular myoid cells in cultures did not stain. In the epididymal sections, strong staining occurred with spermatozoa in the lumen and epididymal epithelial cells, with moderate staining in the myoid layers of epididymis. To determine the sperm antigen interacting with the YWK-II antibody, rat spermatozoa proteins were prepared and analyzed by an immunoblot technique. The monoclonal antibody interacted with a single protein, with an estimated molecular weight of 115,000, present in the cauda epididymal spermatozoa. Among the proteins of the caput epididymal spermatozoa, however, the antibody interacted with a major and a minor band with molecular weights of 115,000 and 88,000, respectively. On the other hand, with proteins prepared from the membrane fraction of adult and immature rat testis, the antibody reacted with two bands with estimated molecular weights of 88,000 and 115,000. In the lysate prepared from germ cells dissociated from Sertoli-germ cell cocultures, the antibody recognized only the 88,000 protein. The present results show that the YWK-II MAb interacts with two proteins with different molecular weights. The amount of the interacting proteins in spermatozoa varied with their location within the epididymis.
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PMID:Identification of antigen in rat spermatogenic cells interacting with an anti-human sperm monoclonal antibody. 331 15

The binding of the spermatozoon to the zona pellucida is a species-specific phenomenon. We have previously shown that the binding of hamster sperm to the homologous zona pellucida involves a sperm 26-kDa glycoprotein, the P26h, originating in the epididymis. In order to establish to what extent this sperm protein is involved in the species-specific recognition of the egg's extracellular coat, we have compared the inhibitory properties of anti-P26h antibodies in a sperm-zona pellucida assay using hamster and mouse gametes. Anti-P26h IgGs inhibit, in a dose-dependent manner, gamete interactions in both species, although in a less efficient manner in the mouse than in the hamster. While anti-26kDa Fab fragments are as efficient as the intact IgG to inhibit hamster sperm-zona pellucida binding, they have no effect on mouse gamete interaction. ELISA, Western blot, and immunohistochemical experiments have been performed in order to characterize the mouse antigen(s) recognized by the anti-P26h antiserum. ELISA and Western blots showed that this antiserum recognized two proteins on mouse spermatozoa that are less reactive than the hamster P26h. These antigens are localized in the acrosomal region of epididymal spermatozoa of both species. These results indicate that the hamster P26H involved in zona pellucida interaction has certain unique epitopes, while others are common to the sperm of both species.
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PMID:Comparative immunoreactivity of mouse and hamster sperm proteins recognized by an anti-P26h hamster sperm protein. 765 78

During epididymal transit, mammalian spermatozoa acquire new surface antigens that may participate in gamete interaction. We have previously described a 26-kDa (P26h) epididymal hamster sperm protein that we propose to be involved in fertilization. In this study, we have searched for an antigenically related protein in the human, and have found that an anti-P26h antiserum recognizes a 34-kDa (P34H) protein on Western blot of human sperm proteins. Immunostaining showed that this protein is localized on the acrosomal cap of human epididymal spermatozoa but not on testicular gametes. The effect of the anti-P26h antiserum on the fertilizing ability of human spermatozoa was evaluated by use of a human zona pellucida binding assay. Compared to the preimmune serum, the antiserum caused a highly significant decrease in the number of sperm bound per zona pellucida. This inhibition was not due to the induction of a premature acrosomal reaction nor to an effect on the motility of the spermatozoa. The antiserum recognizing the P34H human sperm protein had no effect on gamete fusion as determined by the zona-free hamster test. Our results suggest that the human spermatozoon acquires an epididymal protein that shares a common epitope(s) with the P26h hamster sperm protein. The possible involvement of this human sperm antigen in the binding to the zona pellucida is discussed.
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PMID:Human sperm-zona pellucida interaction is inhibited by an antiserum against a hamster sperm protein. 781 37

Several decades ago it was reported that when adult male rats were exposed to a single injection of 50 mg/kg body weight ethane dimethanesulfonate (EDS) and mated with untreated females, average litter size was significantly reduced as early as 2 weeks later. Recently, we demonstrated that EDS exerts multiple effects in the epididymis of adult rats. Some of these effects were independent of reduced serum testosterone (T) levels. Later we found that EDS has direct effects on epididymal epithelial cells in vitro. Herein, we sought to determine whether EDS perturbs the fertilizing ability of cauda epididymal sperm. Four days after exposure to 50 mg/kg EDS, sperm from the proximal cauda epididymidis were inseminated into adult receptive females in utero; on the next day the percentage of fertilized eggs was determined. Exogenous T administration and castration were used to determine what role, if any, androgen deprivation and the testis had on the fertilizing ability of proximal cauda epididymal sperm. Sperm motion parameters, serum T, T in the caput/corpus epididymidis, and detergent-extracted sperm protein were evaluated and correlated with fertilizing ability. We found that both castration and EDS exposure significantly compromised the fertilizing ability of sperm in proximal cauda epididymidis 4 days after exposure. Exogenous T, sufficient to maintain serum T, completely restored the fertilizing ability of sperm following castration, but not after EDS exposure. Moreover, exogenous T failed to restore fertilizing ability when castrated animals were exposed to EDS. Thus, the effects that EDS exerts on sperm maturation in vivo are independent of the testis. Finally, the only endpoint that was well correlated with fertilizing ability was the relative amount of an acidic 18-kDa sperm protein.
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PMID:The ethane dimethanesulfonate-induced decrease in the fertilizing ability of cauda epididymal sperm is independent of the testis. 798

The role of retinoids in the regulation of epididymal fluid protein expression was investigated. We compared the patterns of two-dimensional electrophoretic gels of proteins from luminal fluids, cytosols and spermatozoa (from control rats only) of control, retinoid-depleted, retinoid-depleted retinoic acid-complemented and retinoid-depleted testosterone-supplemented rats. This study compared the luminal fluid patterns from the 4 diets and observed 13 proteins whose expression was dependent on nutritional status. Eight were either absent or very weakly expressed in retinoid-depleted animals only, while their presence was obvious in control rats and in the retinoid-deficient retinoic acid- and testosterone-complemented groups. The expression of 8 proteins was greatly enhanced in retinoid-depleted testosterone-supplemented fluids as compared to control fluids. Five of the regulated proteins seemed to be captured by spermatozoa as they were observed in sperm protein patterns of control rats. These results clearly show that the synthesis of several epididymal proteins is influenced by retinoids. Since testosterone-supplemented animals on retinoid-free diet elicited the same response as retinol and retinoic acid ones, testosterone is likely to be the mediator of retinoid action on epididymal protein synthesis. Nevertheless, the observation of one protein whose expression is stimulated by retinoic acid only and is totally independent of testosterone also favors the direct influence of this retinoid.
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PMID:In vivo regulation of rat epididymal proteins by retinoids: analysis by two-dimensional electrophoresis. 858 80

During epididymal transit, spermatozoa acquire new surface antigens that are involved in the acquisition of their fertilizing ability. We have previously described a 34-kDa (P34H) human epididymal sperm protein that shows antigenic and functional homologies with the hamster P26h. P34H is localized on the acrosomal cap of human spermatozoa and has been proposed to be involved in the interaction with the zona pellucida. The aim of this study was to document the expression of P34H on the sperm surface during transit along the male and female genital tracts. Immunohistochemical techniques were performed on human testes and epididymides by means of an antiserum specific for P34H. No labelling was detected on those spermatozoa found within the seminiferous tubules or in the vasa efferentia. P34H first appeared in the caput epididymidis and was restricted to the acrosomal cap. Signal intensity then increased considerably from the proximal corpus to the cauda region of the epididymis. After ejaculation, the same pattern of P34H distribution was observed, but the intensity was much lower than that characterizing the cauda epididymal spermatozoa. Strong labeling was restored after incubation in B2 medium and was maximal after 5 h of capacitation. After acrosomal exocytosis induced by a Ca2+ ionophore, the percentage of P34H-labeled spermatozoa decreased proportionally to the number of acrosome-reacted spermatozoa as determined by Pisum sativum-fluorescein isothiocyanate (FITC) labeling. P34H appeared to be strongly anchored to the sperm plasma membrane during epididymal transit as indicated by the requirement for detergent to extract this surface antigen from ejaculated spermatozoa. This confirms the importance of P34H binding to the sperm plasma membrane during epididymal maturation. We have previously proposed that P34H is involved in sperm-zone pellucida interaction. The appearance and accumulation of P34H on the sperm plasma membrane during epididymal maturation, followed by its inaccessibility associated with ejaculation, its unmasking during capacitation, and finally its elimination after the acrosome reaction, are in agreement with te proposed function of this sperm antigen.
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PMID:Surface localization of P34H an epididymal protein, during maturation, capacitation, and acrosome reaction of human spermatozoa. 872 20

The interaction of spermatozoa with the zona pellucida is a critical step of fertilization. Specific sperm surface proteins involved in this process can be added or modified during epididymal transit. We have previously described a 34-kDa human epididymal sperm protein (P34H) that we proposed to be involved in sperm-zona pellucida interaction. In this study, Western blot analysis were performed to determine the level of P34H protein present on the spermatozoa of 16 men with idiopathic infertility. These levels were compared with the amount of P34H protein found in men of proven fertility. In addition, a sperm-zona pellucida binding assay was performed with spermatozoa from fertile and infertile men. Spermatozoa obtained from different semen samples from a given individual had similar P34H levels. However, the amount of P34H varied from one man to another. Nine of 16 infertile men had a P34H level that was less than 30% of the normal value based on a population of fertile men, while the remaining 7 males were in the normal range. Sperm from infertile subjects with a normal P43H determination bound to zonae pellucidae as efficiently as those from controls. However, spermatozoa from subjects with a low amount of P34H exhibited a dramatic diminution in their ability to interact with zonae pellucidae. Our results show that the quantity of the epididymal protein P34H varied from one male to another and that low levels of this epididymal sperm protein are associated with certain cases of idiopathic infertility. Results are discussed with regard to the function of human epididymis in sperm maturation.
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PMID:Cases of human infertility are associated with the absence of P34H an epididymal sperm antigen. 872 21

The guinea pig sperm acrosomal matrix is the dense core of the acrosome and is likely to be important in acrosome biogenesis and fertilization. Isolated acrosomal matrices are composed of a limited number of major bands when analyzed by SDS-polyacrylamide gel electrophoresis, among which is a Mr 67,000 protein that we have termed AM67. Indirect immunofluorescence demonstrated that AM67 is localized to the apical segment of the cauda epididymal sperm acrosome. Immunoelectron microscopy further refined the localization of AM67 to the M1 (dorsal bulge) domain within the acrosome. Using a polymerase chain reaction product based upon tryptic peptide sequences from AM67, a lambdagt11 guinea pig testis cDNA library was screened to yield two cDNA clones that encode the AM67 peptides. Northern analysis revealed that AM67 is transcribed as a 1. 9-kilobase testis-specific mRNA. The complete AM67 sequence encodes a prepropolypeptide of 533 amino acids with a calculated Mr of 59, 768. Following cleavage of a probable signal sequence, the polypeptide was predicted to have a Mr of 56,851 and seven consensus sites for asparagine-linked glycosylation. The deduced amino acid sequence of AM67 is most similar to those of the mouse sperm protein sp56 and the alpha-subunits of complement component 4-binding proteins from various mammalian species. Although mouse sp56 has been reported to be a cell-surface receptor for the murine zona pellucida glycoprotein ZP3, standard immunoelectron microscopy using the anti-sp56 monoclonal antibody 7C5 detected sp56 within the mouse sperm acrosome, but failed to detect sp56 on the surface of acrosome-intact mouse sperm. Furthermore, acrosomal labeling was detected in mouse sperm prepared for immunofluorescence using paraformaldehyde fixation, but was not observed with live unfixed sperm. Thus, the finding that sp56 is present within the acrosome provides further support that sp56 and AM67 are orthologues and suggests that sp56 may function in acrosomal matrix-zona pellucida interactions during and immediately following the acrosome reaction in the mouse.
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PMID:AM67, a secretory component of the guinea pig sperm acrosomal matrix, is related to mouse sperm protein sp56 and the complement component 4-binding proteins. 913 29

In a previous study, we found that ethane dimethanesulphonate (EDS) compromised the fertilizing ability of proximal cauda epididymal sperm from the rat within 4 days of exposure, an effect that persisted in castrated, testosterone (T)-implanted animals, establishing direct action on the epididymis. This EDS-induced reduction in fertilizing ability was highly correlated with a quantitative decrease in specific sperm protein. Here we sought to determine whether the fertility of proximal cauda epididymal sperm recovered from animals exposed to a variety of male reproductive toxicants could be predicted by assessing quantitative changes in specific sperm protein(s), or whether more common endpoints (e.g., sperm motility, sperm morphology, serum and epididymal tissue T, cauda epididymal sperm reserves) also are required to predict fertility. Intact adult male rats were dosed with EDS (25 or 50 mg/kg), chloroethylmethanesulphonate (CEMS; 12.5 or 18.75 mg/kg), or epichlorohydrin (EPI; 3 or 6 mg/kg) daily for 4 days. Castrated, T-implanted rats were dosed with hydroxyflutamide (HFLUT; 12.5 or 25 mg/kg) daily for 5 days. On day 5, proximal cauda epididymal sperm were inseminated in utero into receptive, cervically stimulated adult females, and on day 9, fertility (implants/corpora lutea) was assessed. Fertility-was decreased by the higher dose of each toxicant (P < 0.05) and also by the lower dose of EPI and HFLUT. Likewise, an acidic 22 kDa sperm protein (SP22) was decreased quantitatively (P < 0.05) in silver-stained two-dimensional gels by the higher dose of each toxicant as well as by the lower dose of EPI and HFLUT. Although sperm motility and serum T were altered by specific exposures, these endpoints were not useful in predicting fertility. In contrast, SP22 was highly correlated (P < 0.0001; r2 = 0.83) with fertility. Indeed, the amount of SP22 correctly predicted 90% and 94% of the fertile (> 50% fertility) and subfertile (< 50 fertility) animals, respectively, when discriminant analysis was performed. Thus, the amount of SP22 in a cauda epididymal sperm sample may be a useful predictor of fertility in toxicant-treated animals.
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PMID:Discriminant analysis indicates a single sperm protein (SP22) is predictive of fertility following exposure to epididymal toxicants. 915 8

Mammalian spermatozoa gain their fertilizing ability as they mature in the epididymis, a process which is accompanied by oxidation of sperm protein thiols. Since sperm maturation is dependent upon normal androgenic support to the epididymis, the present work was designed to study the effects of castration on thiol status. Spermatozoa and epididymal fluid were isolated from the epididymides of male rats 5 days after castration or after 11 daily injections of the antiandrogen, cyproterone acetate. Spermatozoa and epididymal fluid were labeled with the fluorescent thiol labeling agent monobromobimane. Intact spermatozoa were evaluated by fluorescence microscopy, protein thiols were analyzed by electrophoresis, and fertilizing ability was examined after insemination of sperm suspension into the uterine horns of immature superovulated female rats. We found that both treatments resulted in an increase in cauda sperm thiols as shown by increased fluorescence in the intact spermatozoa. Protamines and nonbasic proteins were found to have increased levels of reactive thiols. The protein profiles of epididymal fluid from castrated rats were different from those of the controls, and the fluorescence patterns corresponded to the protein profiles. Our results indicate that testosterone withdrawal leads to inhibition of sperm thiol oxidation.
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PMID:Effects of castration on thiol status in rat spermatozoa and epididymal fluid. 917 Jan 9


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