Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.1.27.1 (RNase)
16,360 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Gamma-glutamyl transpeptidase (GGT) mRNA-IV is highly expressed in the initial segment of the rat epididymis and is regulated by testicular factors. The promoter region for GGT mRNA-IV contains five conserved polyomavirus enhancer activator 3 (PEA3)-binding motifs (5'-AGGAAG-3'). We hypothesize that PEA3 is present in the rat epididymis and is regulated by one or more testicular factors. Western blot analyses showed that a 62-kDa protein was detected in the nuclear extract from the rat initial segment at higher levels than in the distal epididymal regions. Electrophoretic mobility shift assays (EMSAs) showed that the nuclear extract specifically bound to the PEA3 motif, forming a DNA-protein complex. This complex contained the 62-kDa PEA3 protein as demonstrated by EMSAs and Southwestern analyses. Northern blot analyses and RNase protection analyses showed that PEA3 mRNA was predominantly expressed in the initial segment as compared to the distal epididymal regions and was under the regulation of testicular factors. These results suggest that PEA3 could be involved in the regulation of expression of the rat GGT mRNA-IV gene in response to testicular factors in the initial segment.
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PMID:Identification, expression, and regulation of the transcriptional factor polyomavirus enhancer activator 3, and its putative role in regulating the expression of gamma-glutamyl transpeptidase mRNA-IV in the rat epididymis. 920 98

1. This study was intended to quantify the amounts of the alpha 1-adrenoceptor subtype mRNAs in human vas deferens, and demonstrate the receptor subtype responsible for the vas contraction. 2. The RNase protection assay showed that the mean total amount of alpha 1a mRNA was 7.4 +/- 2.2 pg/5 micrograms of poly (A)+ RNA (97.0% of the total alpha 1 mRNA) in the epididymal portion (E-vas) and 4.9 +/- 0.8 pg/5 micrograms of poly (A)+ RNA (96.3% of the total) in the pelvic portion (P-vas). The E-vas showed a tendency to have a greater alpha 1a mRNA abundance than the P-vas (P = 0.11). The alpha 1b and alpha 1d mRNAs were absent or of extremely low abundance. 3. By an in situ hybridization, the alpha 1a and alpha 1d mRNAs were recognized in the smooth muscle cells of the E-vas and the P-vas, and the distribution pattern the same in both tissue. The alpha 1b mRNA positive site was scarcely detectable in both vas portions. 4. In a functional study, l-phenylephrine produced concentration-dependent contraction in the E-vas (Emax = 2.24 +/- 0.70 g; pD2 = 5.32 +/- 0.09) and the P-vas (Emax = 2.46 +/- 0.46 g; pD2 = 5.07 +/- 0.12). KMD-3213, a novel alpha 1A-adrenoceptor-selective antagonist, caused parallel rightward shifts of the concentration-response curves for l-phenylephrine. Apparent pKB values were 9.90 +/- 0.16 for the E-vas and 9.71 +/- 0.17 for the P-vas. There was no significant difference in Emax, pD2 or pKB estimates between the two portions. 5. We have found that alpha 1a mRNA is predominant in the human vas deferens, and confirmed that contraction of this organ is mediated by the alpha 1A-adrenoceptor.
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PMID:Quantification and distribution of alpha 1-adrenoceptor subtype mRNAs in human vas deferens: comparison with those of epididymal and pelvic portions. 940 62

The expression of the androgen receptor in the human epididymis was analysed by ribonuclease protection, in-situ hybridization and immunohistochemistry. Androgen receptor mRNA and protein could be detected throughout the entire organ, albeit in different quantities, in the caput, corpus and cauda regions, respectively. Also positive, though only weakly, was the ductus deferens, while the efferent ducts were devoid of specific signals. In-situ transcript hybridization and immunocytochemistry localized androgen receptor mRNA and protein primarily to the epithelium of the epididymal duct. In the ductal epithelial cells androgen receptor immunoreactivity showed a distinct nuclear distribution. While peritubular cells occasionally displayed weak signals, interstitial cells as well as blood vessels were consistently negative throughout the entire organ. The observed pattern of androgen receptor expression in the human epididymis supports the notion that the structure and function of the epididymis is differentially controlled by androgens in a region-specific manner, whereas it would not seem compatible with a direct role for androgens in the regulation of epididymal blood flow.
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PMID:Region-specific expression of the androgen receptor in the human epididymis. 943 17

Hyperphagia and obesity can be experimentally induced in rodents by microinjection of 6-hydroxydopamine (6-OHDA) into the ventral noradrenergic bundle (VNAB) to interrupt efferent catecholaminergic pathways to the hypothalamus. Since hypothalamic neuropeptide Y (NPY) is implicated in the control of ingestive behavior, we evaluated hypothalamic NPY activity in this model of obesity. Adult male rats injected bilaterally with 12 microg of 6-OHDA in the VNAB displayed an enhanced rate of body weight gain and selective dark-phase hyperphagia that started at about 10 days postinjection and persisted for the entire duration of the experiment. NPY gene expression, assessed by ribonuclease protection assay, was significantly higher in the hypothalami of 6-OHDA-treated hyperphagic rats during the dark phase (p < 0.01 vs. levels during the light phase and in control, vehicle-injected rats). We also evaluated gene expression of NPY Y and Y5 receptors, receptor subtypes reported to mediate NPY-induced feeding. The dark-phase increase in NPY mRNA was accompanied by the concomitant upregulation of NPY Y5R gene expression, but not of Y1R mRNA levels. Leptin, the peripheral hormone secreted by adipocytes, is believed to maintain body weight and inhibit food intake, most likely by suppressing hypothalamic NPY activity. Evaluation of leptin gene expression in the epididymal fat revealed that the upregulation of leptin mRNA noted during the dark phase in control rats did not occur in 6-OHDA-treated rats. These observations implied that the normal restraint on NPY and feeding exercised by leptin in control rats may be abrogated in 6-OHDA-treated hyperphagic rats due to insufficient levels of leptin. If so, administration of leptin should inhibit food intake in these rats. Indeed, injection of leptin (2 mg/kg, intraperitoneally (i.p.)) on 2 consecutive days reduced 24-h food intake by 25% and significantly reduced body weight. These results suggest that the nocturnal hyperphagia and resultant obesity induced by 6-OHDA injected into the VNAB may be attributed to leptin deficiency concomitant with increased hypothalamic NPY.
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PMID:Evidence that dark-phase hyperphagia induced by neurotoxin 6-hydroxydopamine may be due to decreased leptin and increased neuropeptide Y signaling. 961 6

Several studies have shown that sperm capacitation was accompanied by a change in the lipid composition of the sperm membrane. In cattle, the major proteins of (bovine)seminal plasma (BSP proteins: BSP-A1/A2, BSP-A3, and BSP-30-kDa) potentiate sperm capacitation induced by high-density lipoprotein (HDL). Our recent studies indicate that these proteins and HDL stimulate sperm cholesterol efflux during capacitation. In order to gain more insight into the mechanisms of BSP-mediated sperm capacitation, we studied whether or not BSP proteins induce phospholipid efflux from epididymal sperm membrane. By direct determination of choline phospholipids on unlabeled epididymal sperm, the results show that sperm incubated in the presence of BSP-A1/A2 protein lost 34.4% of their choline phospholipids compared with the control (11.5%). Similar results were obtained using labeled epididymal sperm. Labeling was carried out by incubating washed epididymal sperm for 1 h with medium containing [(3)H]palmitic acid. The majority of the label was incorporated into sperm phosphatidylcholine. Studies of sperm phospholipid efflux were done by incubating the labeled sperm with purified BSP proteins, delipidated BSA, or bovine seminal ribonuclease (RNase, control protein). When labeled ([(3)H]phospholipid) epididymal sperm were incubated with BSP proteins (20-120 microg/ml) for 8 h, the sperm lost [(3)H]phospholipid in a dose-dependent manner (maximum efflux of approximately 30%). After the incubation with BSP proteins, the efflux particles were fractionated by size-exclusion chromatography. Analysis of the fractions obtained showed that the [(3)H]phospholipid was associated with BSP proteins. BSA (6 mg/ml) stimulated a specific phospholipid efflux of approximately 22%. In contrast, bovine RNase (120 microg/ml) did not stimulate phospholipid efflux. These results indicate that BSP proteins participate in the sperm cholesterol and phospholipid efflux that occurs during capacitation.
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PMID:Bovine seminal plasma phospholipid-binding proteins stimulate phospholipid efflux from epididymal sperm. 1045 33

The rat Crisp-1 gene encodes Protein DE (acidic epididymal glycoprotein; AEG), a glycoprotein secreted by the epididymal epithelium that associates with maturing sperm and has been implicated in the process of sperm-egg fusion. Previous characterization of the Crisp-1 messenger RNA in the rat epididymis has demonstrated the presence of 3 splice variants (Klemme et at, 1999). This study was undertaken to determine if expression of the Crisp-1 splice variants in the rat epididymis is region-specific and correlates with the region-specific pattern of synthesis of the D and E forms of the Crisp-1 protein. Expression of each of the splice variants was shown by RNase protection assays to be under the control of androgens, but they are not differentially regulated either within the epididymal segments or along the length of the organ. The reported structure of the mouse Crisp-1 gene does not include an exon that is equivalent to the rat exon 1, suggesting that the rat splice variants cannot exist in the mouse and may be specific to the rat. Furthermore, the mouse transcription start site is situated in a different region of the gene than in the rat. In this study, a comparison of the mouse and rat genes in the region flanking the mouse exon 1 and the rat exon 2 (within the rat intron 1) shows greater than 80% sequence identity, including the conservation of several putative androgen receptor binding sites. In addition, the rat gene is shown to have a corrupted TATA box in intron 1 that corresponds to the TATA box located in the mouse gene. These observations explain the preferential transcription for the mouse gene in this region, while the predominant start site for the rat gene is 5' of the upstream exon 1. Although an exon corresponding to the rat exon 1 has not been found in the mouse gene, reverse transcription-polymerase chain reaction experiments using mouse epididymal RNA suggest that such an exon exists in the mouse gene and is transcribed at low frequency.
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PMID:Expression of crisp-1 mRNA splice variants in the rat epididymis, and comparative analysis of the rat and mouse crisp-1 gene regulatory regions. 1119 Oct 82

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.
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PMID:Cytochrome P450 aromatase in testis and epididymis of male rhesus monkeys. 1182 22

Adrenomedullin (AM) has been found in the brain as well as in various peripheral tissues, including reproductive organs such as the testis and the prostate. Here, we report the expression of AM in the rat epididymis and its role in anion secretion. Whole-epididymal extracts had 35.3 +/- 1.4 fmol of immunoreactive AM per mg of protein, and immunocytochemical studies showed positive AM immunostaining in the epithelial cells. By solution-hybridization-RNase protection assay, preproAM mRNA was detected at high levels in the epididymis. Gel filtration chromatography of AM showed two peaks, with the predominant one eluting at the position of authentic rat AM (1-50). Specific binding of AM to the epididymis, which could be displaced by calcitonin gene-related peptide, was observed. The epididymis also bound to calcitonin gene-related peptide, and this was displaceable by AM. Furthermore, the epididymis was shown to co-express mRNA encoding the calcitonin receptor-like receptor and receptor activity-modifying proteins, RAMP1/RAMP2. The corpus region had the highest AM level and gene expression and the lowest active peptide:precursor ratio. However, mRNA levels of the receptor and the receptor activity-modifying proteins were similar in all regions. In monolayer cultures derived from the rat epididymal cells, AM stimulated short-circuit current on the luminal side in a dose-dependent manner. Our results demonstrate the presence of AM, preproAM mRNA, AM receptors, and specific-binding sites in the rat epididymis as well as the possible role of AM in the regulation of electrolyte and fluid secretion in the epididymis.
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PMID:Co-expression of adrenomedullin and adrenomedullin receptors in rat epididymis: distinct physiological actions on anion transport. 1260 69

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.
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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.
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PMID:Identification of a member of a new RNase a family specifically secreted by epididymal caput epithelium. 1456 40


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