Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

An androgen binding protein (ABP) with an electrophoretic mobility (Rf) of 0.56 is present in the rete testis fluid of adult rams. Its steroid specificity was found to be in the following order: 5alpha-DHT, testosterone, oestradiol-17 beta, dehydroepiandrosterone 5beta-DHT, androstenedione, cyproterone, cyproterone acetate, cortisol and progesterone. The characteristics of the ABP are similar to those found for the ABP of the testis and the epididymis of the rat and the rabbit. The concentration of ABP, determined by the dextran-coated charcoal method and sometimes confirmed by the steady-state polyacrylamide gel electrophoresis method, was significantly higher in the breeding season than in the non-breeding season (4.40 +/- 0.98 X 10(-9) M vs. 2.60 +/- 0.62 X 10(-9) M; P less than 0.037). The affinity constant of the ABP was independent of the season (2.45 +/- 0.21 X 10(9) M-1 vs. 2.66 +/- 0.1 X 10(9) M-1; NS). In addition, ABP was positively correlated with 5alpha-DHT (r = 0.506; P less than 0.0009), testosterone (r = 0.445; P less than 0.0003), total protein (r = 0.329; P less than 0.02) and spermatozoa (r = 0.406; P less than 0.006) in the RTF and with blood plasma testosterone (r = 0.584; P less than 0.0001). Furthermore, testosterone and 5alpha-DHT in RTF were positively correlated (r = 0.582; P less than 0.0001). These androgens were also correlated with plasma testosterone (r = 0.262, P less than 0.052 for testosterone in RTF; r = 0.341, P less than 0.018 for 5 alpha-DHT). Total proteins and spermatozoa were found to be positively correlated in the RTF (r = 0.789; P less than 0.0001).
Mol Cell Endocrinol 1978 Jan
PMID:Studies of the androgen binding protein in the rete testis fluid of the ram and its relation to sexual season. 2 74

We previously demonstrated that the caput epididymis of intact sexually mature rabbits contains a specific high-affinity binding protein for 5alpha-dihydrotestosterone (5alphaDHT). The other anatomical segments (corpus and cauda) of the epididymes of these animals had no detectable 5alphaDHT-binding activity. We have further shown that this binding was due to an androgen-binding protein of testicular origin. In the present study we have investigated 5alphaDHT binding to epididymal cytosol from sexually immature rabbits (20-104 days old). Using sucrose gradient ultracentrifugation, we have detected a unique pattern of binding. The pattern correlated well with testicular and epididymal maturation, but there was little correlation with chronological age or body weight. In the most immature animals (Group I) the seminiferous tubules appeared as solid cords and the epithelium of the ductus epididymis detectable 5alphaDHT-binding activity. In the second group (Group II), there was 5alphaDHT-binding to all three segments. The seminiferous tubules of these rabbits exhibited spermatogenic activity and lumen formation. The height of the epididymal epithelium had increased uniformly throughout the duct. The third group (Group III) had 5alphaDHT-binding only in caput cytosol. Spermatogenesis had progressed to the formation of elongated spermatids in the most immature animals of this group to the release of spermatozoa in the most mature ones. The caput epithelium of this last group of rabbits was fully differentiated. Unilateral orchidectomy of Group II rabbits resulted in a decrease in [3H]5alphaDHT-binding activity on the operated side as compared to the contralateral non-operated control side, suggesting the testicular origin of the binding protein. The failure of cyproterone or cyproterone acetate to inhibit [3H]5alphaDHT-binding to the protein, the lack of effect of N-ethylmaleimide on binding, and the rapid dissociation rate of the [3H]5alphaDHT-binding protein complex suggested that the binding moiety was testicular androgen-binding protein (ABP).
Mol Cell Endocrinol 1975 Sep
PMID:Changes in 5alpha- dihydrotestosterone binding to epididymal cytosol during sexual maturation in rabbits: correlation with morphological changes in the testis and epididymis. 17 Nov 84

Monoclonal antibodies (mAbs) against sperm cells are currently being used in an effort to define spermatozoal antigens involved in the fertilization process. We have produced a number of anti-human sperm mAbs by immunization of female mice with the 100,000 x g supernatant of octylglycoside-solubilized washed human sperm. From a panel of mAbs, 1 antibody, AG7, was selected and characterized due to its fertilization-inhibiting characteristics. MAb AG7 defines a sperm acrosome antigen-1 (SAA-1) located in the acrosomal region of human sperm as evaluated by indirect immunofluorescence. Staining of life sperm cells indicated that the antigen is present on the sperm surface. SAA-1 was also found on sperm of several other mammalian species, implying evolutionary conservation of the antigen. SAA-1 was first observed on testicular sperm and can be followed through epididymal transit, ejaculation, and capacitation. When applied in a mouse in vitro fertilization assay, mAb AG7 inhibits fertilization by greater than 95%, and inhibition is dose dependent, with half-maximal inhibition at 0.8 micrograms/ml. The block to fertilization could not be attributed to sperm agglutination, inhibition of motility, interference with adhesion to the zona pellucida, or inhibition of fusion with the oocyte membrane. MAb AG7 was demonstrated to inhibit calcium influx in spermatozoa in vitro (measured using the fluorescent indicator fura 2), a prerequisite for the acrosome reaction. Initial biochemical characterization of the antigen suggests it is proteinlike in nature, with a molecular weight of approximately 220 kD. The results suggest that SAA-1, identified by mAb AG7, is a sperm antigen crucially involved in the fertilization process, possibly an atypical steroid receptor or ion channel located within the sperm plasma membrane.
Mol Reprod Dev 1992 Dec
PMID:Monoclonal antibody AG7 inhibits fertilization post sperm-zona binding. 128 25

The protein MEP24 was previously described as a glutathione peroxidase-like molecule specifically secreted by the mouse caput epididymidis. Recently, its binding to the head of spermatozoa was demonstrated. Here, the regulation of MEP24 expression was studied by analyzing transcriptional and translational activities in the epididymis (1) of adult mice castrated on day 60 and given various substitutive testosterone (T) treatments from day 90 and (2) of hemicastrated adult animals. In castrated mice, T treatment induced a significant rise in plasma T and 5 alpha-dihydrotestosterone (DHT) concentrations that greatly exceeded the control values. Owing to efficient regulation, however, the epididymal T and DHT levels were never higher than those of the controls. The restoration of MEP24 mRNA accumulation was complete when the epididymal DHT content returned to its normal value. However, when estimated in a cell-free system, the in vitro translatable MEP24 mRNA level never exceeded 70% of control values, even though the DHT and accumulated mRNAs were restored by 100% or more. In hemicastrates, the T content was normal on the castrated side, while the DHT content exhibited a significant decrease (47%). In this case, the MEP24 mRNA accumulation reached 88% of the normal value, but the translation rate, both in vitro and in vivo, was only about 50%. Ultrastructural studies showed that the normal rough endoplasmic reticulum organization in segment I cells is dependent upon the presence of testicular fluid in the epididymal duct lumen. Thus, this report shows that the MEP24 mRNA steady-state level is completely recovered in the presence of a normal epididymal DHT content, while restoration of the regulation of translation is just partial. This could be related to the cell organization but seems mainly dependent upon the presence of specific mRNA-associated factors which are probably under the control of androgens and/or molecules carried by the testicular fluid.
Mol Cell Endocrinol 1992 Nov
PMID:Regulation of the epididymal glutathione peroxidase-like protein in the mouse: dependence upon androgens and testicular factors. 130 85

DNase I-hypersensitivity of rat spermatogenic cells was analyzed 1) to establish overall patterns of hypersensitivity in individual cell types, 2) to correlate these patterns with known changes in chromatin organization and function, and 3) to provide a foundation for further analyses examining DNase I-hypersensitivity and the localization of specific genes during spermatogenesis. Parameters for in situ nick translation, using radioactive and fluorescent probes to visualize DNase I-hypersensitive regions (DHR), were established for fixed and sectioned testicular preparations, permeabilized cells, and isolated germ cell nuclei. As anticipated, the pattern of DHR changed in a cell-type specific manner during the course of spermatogenesis, reflective of known stage-dependent alterations in the composition and structure of both the chromatin and the nuclear lamina/matrix as well as changes in gene expression. DHR in preleptotene spermatocytes were primarily peripheral, while in pachytene spermatocytes they were localized along the condensed chromosomes. The pattern of DHR changed from "checkerboard" in steps 7-8 round spermatid nuclei to "lamellar" in steps 10-11 elongating spermatids. In steps 12-13 elongating spermatids. DHR were localized throughout the nuclei or in a graded manner--increasing from anterior to posterior and mirroring the pattern of chromatin condensation. However, unlike the case in other stages, DNA of steps 12-13 elongating spermatids was exquisitely sensitive to nick translation even in the absence of exogenous DNase I. In contrast to the labeling of earlier stages, steps 16-19 spermatids and mature spermatozoa did not demonstrate DNase I-hypersensitivity under any conditions employed. A variety of agents that interact with topoisomerase II and DNA (teniposide, novobiocin, ethidium bromide, and adenosine triphosphate) were tested to determine the basis for the unique sensitivity to nick translation of steps 12-13 elongating spermatids. None of the agents tested, however, affected this unique labeling. The sensitivity of steps 12-13 elongating spermatids to nick translation in the absence of exogenous nuclease indicators the presence of endogenous nicks, which may relieve torsional stress and aid rearrangement as the chromatin is packaged into a form characteristic of the mature spermatozoon.
Mol Reprod Dev 1992 Apr
PMID:Localization of DNase I-hypersensitive regions during rat spermatogenesis: stage-dependent patterns and unique sensitivity of elongating spermatids. 131 43

Acrosomal reaction is an essential prerequisite to fertilization. The changes in lipid composition of sperm membranes cause fusion of the plasma and outer acrosomal membranes that results in the exocytosis of acrosomal contents. We report that both bull and rabbit spermatozoa contain a phosphatidylcholine-specific phospholipase C (PC-PLC) that hydrolyzes L-alpha-dipalmitoyl-(choline-methyl-14C-153.0 Ci/mmol and a phosphatidylinositol-specific phospholipase C (PI-PLC) that hydrolyzes L-alpha-(Myo-Inositol-2-3H (N)-5.2 Ci mmol. PI-PLC from bull sperm acrosome has been purified 568 x fold with a specific activity 6.25 +/- 0.6 nmol/min/mg protein, km 0.004 mM, and Vmax 12 nmol/min/mg protein. Both enzymes had optimum at pH 7.5. The activity of PC-PLC remained unaffected by varying concentrations of Ca2+, whereas PI-PLC activity was significantly increased. The bulk of PI-PLC was found to be associated with inner acrosomal membrane of bull and rabbit sperm, while PC-PLC was found in the outer acrosomal membranes in the bull sperm and the plasma membrane of the rabbit sperm. Both enzymes are compartmentalized in sperm cell.
Mol Reprod Dev 1992 Nov
PMID:Phosphatidylcholine and phosphatidylinositol-specific phospholipases C of bull and rabbit spermatozoa. 133 40

Appropriate software settings and optimum procedures were determined for the measurement of the motion parameters of rabbit spermatozoa by the CellSoft (Cryo Resources Ltd., Montgomery, NY) computer-assisted digital image analysis system. The system was used to follow motion parameter changes occurring in spermatozoa incubated for 6 hr with or without exposure to chemicals. Mean amplitude of lateral head displacement (AALH) increased over the 6 hr period, while curvilinear velocity (Vc) first increased and then decreased. Values for linearity (Lin), or beat cross frequency (BCF), were unchanged. The majority of spermatozoa progressed linearly, with rapid rotation of the sperm head, but subpopulations of spermatozoa with different swimming patterns appeared after 1-3 hr of incubation. Percentage motile sperm and Vc were most sensitive to the action of the compounds (pyrogallol, hydroquinone, ammonium oxalate, triethyl phosphite, and pinocolyl alcohol), while BCF was least affected. The decline in percentage of motile sperm was dependent on duration of exposure and chemical concentration. Mean Vc of the sperm population decreased rapidly upon chemical exposure and remained at a low value until motility ceased. The initial decrease in Vc was dependent on the concentration of the added compound. Motion-based indices--motility concentration (MCI50), motility time (MTI50), and velocity (VI)--were defined and used as toxicological endpoints. The rank order of these indices, the end point of the neutral red in vitro assay for cytotoxicity, and LD50 values for the five compounds were the same, suggesting that chemical inhibition of sperm motility may be useful as a method for the in vitro assessment of chemical cytotoxicity.
Mol Reprod Dev 1992 Nov
PMID:Automated analysis of rabbit sperm motility and the effect of chemicals on sperm motion parameters. 133 42

The human zona pellucida (ZP) and its changes during in vitro fertilization in oocytes at different maturational stages and polypronuclear ova at one- to four-cells stages were studied by transmission electron microscopy (TEM) and correlative scanning electron microscopy (SEM). To define the microstructure of the ZP, its amorphous masking material was removed using a detergent (saponin), and its structural glycoproteins were stabilized with a cationic dye, ruthenium red, followed by osmium-thiocarbohydrazide treatment. These methods allowed in all samples the clear visualization of variously arranged networks of filaments composing the outer and inner surfaces of the ZP. These filaments were straight or curved, 0.1-0.4 microns in length and 10-14 nm thick as seen via TEM or 22-28 nm thick as seen via SEM (the difference in thickness was due to the presence of the metal coating for SEM). The filament arrangement was remarkably different between the inner and outer surfaces of the ZP and among the various stages studied. The filaments of the outer surface of the ZP were basically arranged in "large" and "tight" meshed networks. Mature oocytes and fertilized (polypronuclear) ova had a regular alternating pattern of wide and tight meshed networks of filaments. On the other hand, immature and atretic oocytes displayed almost exclusively a tight meshed network of filaments. The inner surface filaments of the ZP of unfertilized oocytes at any stage were arranged in repetitive structures characterized by numerous short and straight filaments anastomosing with each other and sometimes forming at the intersections small, rounded structures. After fertilization, the inner surface of the ZP displayed numerous areas where filaments fused together. Collectively, these data clearly reveal that oocyte maturation and fertilization in humans are accompanied by changes of ZP filaments arrangement, which may be relevant in the processes of binding, penetration, and selection of spermatozoa.
Mol Reprod Dev 1992 May
PMID:Human zona pellucida during in vitro fertilization: an ultrastructural study using saponin, ruthenium red, and osmium-thiocarbohydrazide. 138 Nov 98

Sperm coating proteins of 16, 17, and 19 kDa have been purified from boar seminal plasma. The 17 kDa protein has been identified as an antigen recognized by monoclonal antibody ACR.3 and is thus identical to low molecular mass zona pellucida binding protein from boar spermatozoa (Moos et al., 1990). The 17 and 19 kDa proteins are glycosylated and tend to form hetero-complexes. The 17 kDa ACR.3 antigen is sequentially released from the sperm cell surface during capacitation and, after induction of the acrosome reaction, the 16 kDa form was also observed. Immunocytochemical studies on boar reproductive tissues have suggested that the seminal vesicle epithelium may be the source of these proteins.
Mol Reprod Dev 1992 Oct
PMID:Purification and partial characterization of the 17 kDa sperm coating protein from boar seminal plasma. 141 85

The presence of actin has been determined in mammalian spermatozoa. However, its function in these cells is still almost unknown. Only in boar spermatozoa has evidence for F-actin and a possible function for it been presented. In this work, actin distribution and F-actin were determined in uncapacitated, capacitated, and acrosomal-reacted guinea pig spermatozoa, by means of monoclonal and polyclonal antibodies, using an indirect immunoperoxidase technique, and by the use of rhodamine-phalloidin. With the last probe we found filamentous actin in these cells. By both techniques, actin was detected in the acrosome and in the entire tail. In some cells with acrosomal reaction, actin was also detected in the equatorial and in the postacrosomal regions. SDS-PAGE and Western blots immunostained with monoclonal and polyclonal anti-actin antibodies confirmed the presence of actin in extracts of guinea pig spermatozoa. Actin was also detected in preparations of Percoll-purified spermatozoa. We have communicated that guinea pig spermatozoa show a change on calmodulin location during the acrosome reaction. They present it first in the equatorial region and later in the postacrosomal region. To determine if F-actin participates in this calmodulin translocation, we studied the effect of cytochalasin D. It was found that the number of cells with calmodulin in the equatorial region increased in the presence of cytochalasin D while the number of cells with calmodulin in the postacrosomal region decreased. We also found that after cytochalasin D treatment acrosome loss was increased and sperm motility was slightly inhibited. Our results suggest that actin participate in calmodulin translocation to the postacrosomal region during acrosome reaction, in maintaining the acrosome structure, and perhaps also in sperm motility.
Mol Reprod Dev 1992 Oct
PMID:F-actin in guinea pig spermatozoa: its role in calmodulin translocation during acrosome reaction. 141 86


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