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)

Acidic epididymal glycoprotein (AEG) is an androgen-regulated, epididymal secretory protein assumed to be involved in sperm maturation. In the present study, we show that the mouse submandibular gland (SMG) expresses two genes designated Aeg-1 and Aeg-2. The nucleotide sequence of Aeg-1 cDNA clones was identical to that of epididymis-expressed Aeg cDNA clones, indicating that Aeg-1 is expressed in both epididymides and SMGs. The second, more abundant transcript, Aeg-2, had a sequence similar to, but distinct from, that of Aeg-1, and was not detectable in the epididymis. The level of Aeg-1 and Aeg-2 transcripts in the SMG was androgen-regulated and showed sexual dimorphism. In situ hybridization of SMG sections showed that Aeg-1 and Aeg-2 transcripts are produced by the cells of granular convoluted tubules. The C-terminal cysteine-rich region of the mouse AEG-2 molecule appears to have diverged faster than that of the mouse AEG-1 molecule, consistent with the idea that this region may play a role unique to the protein of the male reproductive system.
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PMID:Mouse submandibular glands express an androgen-regulated transcript encoding an acidic epididymal glycoprotein-like molecule. 130 83

A 25-kDa epididymal secretory protein (MEP 9), isolated from mouse epididymal fluid, has recently been characterized in our laboratory [Rankin et al., Biol Reprod 1992; 46:747-766]. The polyclonal antibody raised against this protein was found to recognize a 25-kDa component in epididymal fluid and testicular extract. The 25-kDa testicular antigen (MTP) was purified by means of ammonium sulfate precipitation, gel filtration, and anion-exchange chromatography; MTP was found to be similar to MEP 9 in several properties including molecular mass (25 kDa), isoelectric point (pI 6.0), and immunoreactivity when the proteins were resolved in the presence of SDS (one-dimensional and two-dimensional PAGE). However, when the proteins were resolved under non-denaturing conditions, MTP showed strong immunoreactivity while MEP 9 did not. This observation suggests that although the 25-kDa antigens from the epididymal fluid and testicular extract are quite similar, they may have different immunological conformations. When analyzed for amino acid composition and partial amino acid sequence, the testicular antigen showed substantial homology (> 80%) with a phosphatidylethanolamine-binding protein characterized from bovine brain. MTP also showed phosphatidylethanolamine-binding activity (Kd = 1.95 x 10(-5) M, Bmax = 1.86 nmol/micrograms MTP), suggesting that the mouse 25-kDa protein is a member of the phospholipid-binding protein family and may have a role in lipid metabolism during sperm maturation.
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PMID:Isolation and characterization of a 25-kilodalton protein from mouse testis: sequence homology with a phospholipid-binding protein. 147 9

A polypeptide with molecular mass of 17 kDa has been partially purified and identified as a major secretory glycoprotein in the rat epididymis. It is phosphorylated and contains high mannose-type oligosaccharides with 5 and 6 mannose units predominantly. These sugar residues are sufficiently exposed in the molecule to be released by endo-beta-N-acetylglucosaminidase H without prior denaturation or protease digestion. Specific binding of the glycoprotein to testicular spermatozoa was demonstrated with Ka 0.2 x 10(9) M-1 and 17,200 sites per cell, while no binding to epididymal spermatozoa was detectable. Direct labeling of surface proteins on cauda epididymis spermatozoa revealed the presence of a major band of 16.2 kDa, which may be equivalent to GP17. The interaction of the epididymal secretory protein with sperm suggests a possible role in the maturation process.
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PMID:Identification of a major secretory glycoprotein from rat epididymis: interaction with spermatozoa. 272 28

A screening strategy designed to identify cloned cDNAs encoding abundant Macaca fascicularis epididymal transcripts has yielded a clone corresponding to a 1.03-kb transcript present at high levels in the epididymis. Following library rescreening, DNA sequence analysis of several near full-length clones predicts a novel, 151-amino-acid protein, epididymal secretory protein 14.6 (ESP14.6), which contains a strong candidate signal peptide characteristic of secretory proteins.
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PMID:The monkey ESP14.6 mRNA, a novel transcript expressed at high levels in the epididymis. 787 8

The sperm coating lizard epididymal secretory protein (LESP) family forms a complex of nine elements that are specifically synthesized under androgenic control and secreted by the epididymal epithelial cells of the lizard Lacerta vivipara. We report here the cloning and sequencing of an 806-base pair full-length cDNA (C731) encoding one of the elements of the LESP family. Southern blot hybridization analysis of lizard total genomic DNA revealed a complex band pattern, suggesting that LESPs are encoded by a multigenic family. The cDNA open reading frame of 516 nucleotides, starting at an ATG codon, encodes a protein precursor of 172 amino acids with a calculated M(r) = 19,500. The corresponding mature form of M(r) = 17,200 and pI = 5.2 has been identified as the element LESP IV, and presents significant similarities to the different members of the large lipocalin protein superfamily, and especially to mouse epididymal protein ESP I. Lipocalins are extracellular proteins that share a common basic framework for the transport of small hydrophobic molecules like retinoids, thus suggesting that LESPs could be such transporters into the epididymal fluid during the sperm maturation.
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PMID:LESP, an androgen-regulated lizard epididymal secretory protein family identified as a new member of the lipocalin superfamily. 848 91

Acidic epididymal glycoprotein (AEG) is an androgen-dependent, epididymal secretory protein assumed to play a major role in sperm maturation. In the present study, we isolated cDNA clones encoding the human AEG-like molecule and determined their nucleotide sequences. The deduced human AEG-like molecule was made up of 230 amino acids, excluding a signal peptide, and contained one potential N-linked glycosylation site. All cysteinyl residues were conserved between the human AEG-like molecule and the AEG molecules of rats and mice. The human AEG-like molecule was equally similar to the AEG molecules of rats and mice and a related testis-specific protein known as TPX1 of human and mice (approximately 40% amino acid sequence similarity). Northern blot analysis showed that the human AEG-like gene is expressed specifically in the epididymis. To identify the product of the human AEG-like gene, polyclonal antibody was produced by immunizing rabbits with a recombinant human AEG-like protein expressed in E. coli. This antibody detected a major band of 30 kD and a minor band of 26 kD in the caput, corpus, and cauda regions of the epididymis, the ductus deferens, the sperm, and the seminal plasma. Immunohistochemical analysis showed that the human AEG-like molecule is located in the lumen and epithelium of distal ductus efferentes and epididymal ducts, and on the postacrosomal region of the sperm head.
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PMID:[Analysis of the human acidic epididymal glycoprotein-like molecule: isolation of cDNA and tissue localization]. 854 80

A complementary DNA encoding the mouse epididymal secretory protein MEP 10 (mouse epididymal protein 10) was cloned and is now renamed murine epididymal retinoic acid binding protein (mE-RABP). The analysis of the predicted primary amino acid sequence showed that mE-RABP has a 75% identity with rat ESP I (epididymal secretory protein I), another epididymal retinoic acid-binding protein. The homology strongly suggests that mE-RABP is the mouse orthologue of rat ESP I. A computer analysis of the predicted three-dimensional structure confirmed that mE-RABP can accommodate retinoic acid as ligand. In the rat, ESP I messenger RNA (mRNA) is expressed in the efferent ducts and in the entire caput epididymidis. However, in the mouse, the expression of a 950-bp mE-RABP mRNA was detected only in principal cells of the mid/distal caput epididymidis, suggesting that the regulation of region-specific expression is different in rat and mouse. Northern blot analyses showed that mE-RABP gene expression is no longer detected 10 days after castration but progressively rebounds between days 15 and 60. However, mE-RABP protein could not be detected by Western blot 30 days after castration. Androgen replacement, begun 5 days after castration and continued for 4 days restored significant expression of mE-RABP mRNA. Efferent duct ligation for 10 days did not affect gene expression. Taken together, these results indicate that mE-RABP mRNA expression is regulated by androgens but not by testicular factors. The overall similarity in the primary amino acid sequence of mE-RABP with ESP I and other members of the lipocalin superfamily suggests that they are evolutionarily related.
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PMID:Molecular cloning and hormonal regulation of a murine epididymal retinoic acid-binding protein messenger ribonucleic acid. 960 8

The murine epididymal retinoic acid-binding protein (mE-RABP) is specifically synthesized in the mouse mid/distal caput epididymidis and secreted in the lumen. In this report, we have demonstrated by Southern blot analysis of genomic DNA that mE-RABP is encoded by a single-copy gene. A mouse 129/SvJ genomic bacterial artificial chromosome (BAC) library was screened using a cDNA encoding the minor form of mE-RABP. One positive BAC clone was characterized and sequenced to determine the nucleotide sequence of the entire mE-RABP gene. The molecular cloning of the mE-RABP gene completes the characterization of the 20.5-kDa-predicted preprotein leading to the minor and major forms of mE-RABP. Comparison of the DNA sequence of the promoter and coding regions with that of the rat epididymal secretory protein I (ESP I) gene showed that the mE-RABP gene is the orthologue of the ESP I gene that encodes a rat epididymal retinoic acid-binding protein. Several regulatory elements, including a putative androgen receptor binding site, "CACCC-boxes," NF-1, Oct-1, and SP-1 recognition sites, are conserved in the proximal promoter. Analysis of the nucleotide sequence of the mE-RABP gene revealed the presence of seven exons and showed that the genomic organization is highly related to other genes encoding lipocalins. The mE-RABP gene was mapped by fluorescent in situ hybridization to the [A3-B] region of the murine chromosome 2. Our data, combined with that of others, suggest that the proximal segment of the mouse chromosome 2 may be a rich region for genes encoding lipocalins with a genomic organization highly related to the mE-RABP gene.
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PMID:Genomic organization and chromosomal localization of the murine epididymal retinoic acid-binding protein (mE-RABP) gene. 966 22

Vitamin A is required to maintain the epididymal epithelium. In this report, the characterization and putative functions of a murine epididymal retinoic acid-binding protein (mE-RABP) that is secreted into the lumen from the mid-/distal caput epididymidis are discussed. The amino acid sequence analysis of the mE-RABP preprotein shows that mE-RABP is the mouse orthologue of the rat epididymal secretory protein I (ESPI). These proteins belong to the lipocalin superfamily and bind to active retinoids but not to retinol. Therefore, we propose that mE-RABP may function as an extracellular retinoid carrier-protein involved in the paracrine regulation of epididymal function by retinoids.
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PMID:Structure and putative function of a murine epididymal retinoic acid-binding protein (mE-RABP). 1064 66

Early studies in which the electrophoretic profiles of fluid from different regions of the epididymis were compared with other body fluids, such as blood serum, suggested that many proteins present in epididymal fluid were not found in other secretions and thus might be tissue specific. Comparative studies of epididymal fluid from different species further emphasized differences so that some epididymal proteins are considered both tissue and species specific. Such proteins are the putative molecular agents responsible for the array of changes undergone by spermatozoa during maturation. Thus a complete characterization of all the specific proteins secreted by the epididymis would yield important information for understanding the molecular events of maturation. Comparison of these proteins across species would determine whether the proteins and mechanisms at the centre of changes such as acquisition of fertilizing ability are conserved during evolution. This review critically examines the evidence for both tissue and species specificity of epididymal secreted proteins, describes how advances in molecular biology can be used to clarify this issue and concludes with a description of some preliminary work with different lagomorph species involving the REP 52 protein, an epididymal secretory protein that binds specifically to spermatozoa in New Zealand white rabbits.
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PMID:The specificity of epididymal secretory proteins. 1064 78


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