Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.27.4 (ribonuclease)
 6,621 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Aldosterone acts via mineralocorticoid receptors (MRs) to control salt and water flux in epithelial organs such as the kidney and colon to maintain circulatory homeostasis. Inappropriate glucocorticoid-mediated activation of MRs in aldosterone-target tissues is prevented by the glucocorticoid-metabolizing enzyme 11beta-hydroxysteroid dehydrogenase type 2 (HSD2). We have studied HSD2 expression in the mouse at the level of gene transcription and further analyzed, with HSD1, its pattern of tissue-restricted gene expression. The mouse HSD2 gene, including upstream regulatory regions, has been cloned, and its transcription start site has been mapped in colon and kidney. A 2.5 kb upstream region has been sequenced, and its proximal promoter region has been analyzed. We have compared the relative expression of HSD1 and HSD2 in a variety of tissues from male mice using ribonuclease protection analysis. HSD1 was expressed in liver, kidney, adrenal, lung, spleen, thymus, fat, small intestine, stomach, heart, skin, and epididymis. HSD2 was expressed in kidney, colon, small intestine, stomach, and epididymus. No expression of either HSD1 and HSD2 was detected in bladder, testis, seminal vesicles, vas deferens, prostate, or skeletal muscle. Finally, to investigate the specific roles of HSD2 in vivo, we have created "floxed" HSD2 alleles using gene targeting in mouse embryonic stem cells with the aim to create tissue-specific ablation of HSD2 in mice via Cre recombinase mediated gene targeting.
 ...
PMID:Expression of the 11beta-hydroxysteroid dehydrogenase 2 gene in the mouse. 1076 59

To understand the role of estrogen in testicular and epididymal function of rhesus monkeys, we measured steroids in the spermatic and peripheral venus circulation and aromatase activity and its mRNA in testis and epididymis. Testosterone, estradiol-17beta, and estrone, but not androstenedione, were elevated in the spermatic vein serum compared to the peripheral circulation. Aromatase activity in testis and in caput epididymis (259+/-16 [SEM] vs 274+/-47 fmol of 3H2O/mg of protein/h [n = 10], respectively) was significantly higher (p < 0.01) than in corpus and cauda (124+/-28 and 113+/-33 fmol of 3H2O/mg of protein/h [n = 10], respectively). In the ribonuclease protection assay, two P450arom mRNA transcripts were identified in testis and epididymis. One corresponded with the aromatase full-length transcript and the other was a truncated isoform. The latter was significantly more abundant than the former (p < 0.01). Our results demonstrate that the monkey testis and, to a lesser extent, the epididymis can aromatize androgens. However, in the epididymis, like in some areas of the brain, there was a discrepancy between the aromatase activity and the mRNA. The fact that P450arom mRNA and aromatase activity do not correlate in the epididymis may indicate that aromatase activity is not strictly regulated at the level of RNA expression and that other mechanisms for this regulation should be considered.
 ...
PMID:Cytochrome P450 aromatase in testis and epididymis of male rhesus monkeys. 1182 22

Epididymal proteins interact with sperm during their passage through the epididymis and thus contribute to the maturation and fertilizing capacity of the spermatozoa. In the present study we have discovered five novel epididymis-specific genes through in silico analysis of expressed sequence tags (ESTs) at the UniGene library collection. The strategy used is a powerful way to discover novel epididymis-specific genes. The full-length cDNA sequences were determined, and computational tools were used to characterize the genomic structures and to predict putative functions for the encoded proteins. In vitro analyses revealed that all five genes characterized were highly expressed in the defined areas of the epididymis, and they were not expressed at significant levels in any other tissue. Three of the genes were named on the basis of their putative functions: Spint4 (serine protease inhibitor, Kunitz type 4), and Rnase9 and Rnase10 (ribonuclease, Rnase A family 9 and 10), while for the ESTs AV381130 and AV381126 no putative functions could be predicted. The expression of Spint4, Rnase9, and AV381130 was found to be under a direct or indirect regulation by androgens, while the expression of Rnase10 is regulated by a testicular factor(s) other than androgen. None of the genes were expressed in the immature epididymis, while mRNAs were detected from d 17 onward, at the time of maturation of epididymal epithelium. However, the expression of AV381130 was not detected until d 30 after birth, indicating a close connection between gene expression and puberty.
 ...
PMID:Discovery in silico and characterization in vitro of novel genes exclusively expressed in the mouse epididymis. 1292 Feb 33

In this study, we purified the first member of a new ribonuclease (RNase) A family from fluid of the proximal caput of the boar epididymis. This protein, named "Train A," is the most abundant compound secreted in the anterior part of the boar epididymis. After 2D electrophoresis, it is characterized by more than 10 isoforms ranging in size from 26 to 33 kDa and pI from 5 to 8.5. Several tryptic peptides were N-terminal sequenced, and an antiserum against one of these peptides was obtained. The protein was immunolocalized in the epididymal epithelium of the proximal caput, especially in the Golgi zone and the apical cytoplasm of the principal cells. In the lumen, spermatozoa were negative but droplets of reaction product were observed within the lumen. Full lengths of Train A cDNA were obtained from a lambdagt11 boar caput epididymis library and sequenced. The deduced protein is composed of 213 amino acids, including a 23-amino acid peptide signal and a potential N-glycosylation site. The mRNA of this protein has been retrieved and partially sequenced in the bull, horse, and ram, and homologous cDNA is found in databanks for the rat, mouse, and human. All the sequences are highly conserved between species. This protein and its mRNA are male-specific and exclusively expressed in the proximal caput of the epididymis, the only site where they have been found. Train A presents an RNase A family motif in its sequence. The RNase A family is a group of several short proteins (20-14 kDa) with greater and lesser degrees of ribonucleolytic activity and with supposed different roles in vivo. However, the presence of a long-conserved N-terminal specific sequence and the absence of RNase catalytic site for Train A indicate that Train A protein is a member of a new family of RNase A.
 ...
PMID:Identification of a member of a new RNase a family specifically secreted by epididymal caput epithelium. 1456 40

Ribonuclease, RNase A family, 9 (RNASE9) is a ribonuclease A superfamily member that is expressed only in the epididymis. It is a small, secreted polypeptide, it lacks ribonuclease activity, and its function(s) is unknown. However, epididymis-specific expression suggests a role in sperm maturation. We generated Rnase9(-/-) mice to study RNASE9 function in vivo. We confirm that RNASE9 expression is restricted to the epididymis. Within the epididymis, RNASE9 is first detected in midcaput, persists through the distal caput and corpus, and wanes in the cauda. Rnase9(-/-) mice are born at the expected Mendelian ratio, have normal postnatal growth and development, and have no outwardly apparent phenotype. Spermatogenesis is normal, and Rnase9-null sperm are morphologically normal. Rnase9(-/-) males have normal fertility in unrestricted mating trials, and fertilization rates in in vitro fertilization assays are indistinguishable from wild-type mice. Visual observations coupled with analyses of sperm velocities shortly after swim out from the corpus shows that motility of Rnase9-null sperm is significantly impaired. However, no differences between wild-type and Rnase9-null sperm are detected by computer-assisted sperm analysis 10-90 min after sperm isolation from the corpus or cauda. Assessment of capacitation-dependent signaling pathways in Rnase9-null sperm showed that, while levels of tyrosine phosphorylation of sperm proteins were normal, there was decreased phosphorylation of protein kinase A substrates upon capacitation compared to wild-type mice. In conclusion, RNASE9 is dispensable for fertility, but the absence of RNASE9 during epididymal transit results in impaired sperm maturation.
...
PMID:Impaired sperm maturation in RNASE9 knockout mice. 2471 58


<< Previous 1 2