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)

Relatively little is known about the transcriptional control of genes expressed late after T cell activation. We have identified four genes expressed 3 to 5 days after T cell activation by alloantigen or mitogen. Here we report the genomic organization of 519, one of these late T cell activation Ag. Analysis of the genomic clone revealed that 519 consists of six exons. Ribonuclease protection experiments indicated that the most abundant transcript arising from this region is an alternatively spliced form of 519, referred to as 520, which lacks exon 2 and is similar in sequence to NKG5, a cDNA identified in NK cells. These experiments also revealed the existence of two other alternatively spliced RNA transcripts, with heterogeneity in exon 2. Primer extension analysis and ribonuclease protection assays demonstrated that there are two prominent start sites for transcription; however, there is no evidence for the NKG5 transcript in T cells, indicating that NKG5 may represent a NK cell-specific form of 520. The 5' flanking region of this gene contains several previously identified sequences involved in transcriptional regulation, as well as some potentially interesting novel conserved motifs.
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PMID:Genomic structure and alternative splicing of 519, a gene expressed late after T cell activation. 131 39

The 52-kD SS-A/Ro protein is one of the antigenic targets strongly associated with the autoimmune response in mothers whose children have manifestations of neonatal lupus. In addition to the cDNA clone we previously reported for the full-length 52-kD SS-A/Ro protein, an interesting MOLT-4 cDNA clone, p52-2, was found to have an internal deletion of 231 nucleotides including the domain encoding the leucine zipper motif. To further investigate the nature of this deletion, genomic DNA clones were isolated from a lambda FIXII library. The complete gene for the full-length 52-kD protein (alpha form, 52 alpha) spans 10 kb of DNA and is composed of seven exons. Exon 1 contains only the 5' untranslated sequence, while the translation initiation codon is located 3 kb downstream in exon 2, which also encodes the three zinc finger motifs. Exon 4 encodes amino acids 168-245, including the coiled coil/leucine zipper domain. Exon 7 is the longest and encodes the rfp-like domain and the 3' untranslated region. The cDNA p52-2 can now be accounted for as a product of alternative messenger RNA (mRNA) derived from the splicing of exon 3 to exon 5, skipping exon 4, which results in a smaller protein (52 beta) with a predicted molecular weight of 45,000. An initial approach to identifying this alternatively spliced form in the human heart used a ribonuclease protection assay. Using an RNA probe corresponding to bases 674-964 of the full-length cDNA, two protected mRNA fragments were identified, a 290-bp fragment corresponding to expression of 52 alpha and a smaller fragment of 144 bp, the predicted size of 52 beta. Using reverse transcription followed by polymerase chain reaction, cDNAs from a 16-wk fetal heart, 24-wk heart, and adult heart were amplified with primers flanking exon 4. Two polymerase chain reaction products were observed in each tissue, one 1.0 kb likely representing 52 alpha and a second 0.78 kb, consistent with 52 beta. The 0.78-kb fragment identified in the 16-wk heart was cloned, and DNA sequencing confirmed the 52 beta type. Immunoprecipitation of in vitro-translated 35S-labeled 52 beta form was performed to evaluate the antigenicity of this novel form of 52-kD SS-A/Ro. 26 (87%) of 30 sera tested from mothers whose children were known to have neonatal lupus immunoprecipitated the 52 beta form.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:52-kD SS-A/Ro: genomic structure and identification of an alternatively spliced transcript encoding a novel leucine zipper-minus autoantigen expressed in fetal and adult heart. 756 1

To examine the mechanisms responsible for tissue-specific, nutritional, and metabolic regulation of the GLUT4/muscle-adipose specific glucose transporter, we isolated and characterized the properties of the rat GLUT4 gene. Examination of the sequenced 2.5-kilobase flanking DNA revealed substantial identity with that of the mouse and human GLUT4 genes, with the greatest degree of sequence identity within the proximal 1000 basepairs up-stream of the GLUT4 open reading frame. Primer extension analysis identified a unique single transcription initiation site 176 basepairs up-stream from the start of translation. However, ribonuclease mapping revealed the presence of a previously undescribed alternatively spliced form of GLUT4 messenger RNA. Approximately 75% of the GLUT4 transcripts consisted of a fully spliced messenger RNA, and 25% was expressed as an unspliced intron-containing species. The ratios of 5' spliced and unspliced messages were invariant in adipose, cardiac, and skeletal muscle tissues. In vitro translation of reporter constructs containing both the spliced and unspliced leader demonstrated a functional difference between these two transcripts, with the unspliced form translated approximately 5-fold more than the fully spliced species. These data demonstrate the presence of 5'-heterogeneity of the GLUT4 transcripts, which underlies differences in translational efficiency in vitro.
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PMID:Characterization of 5'-heterogeneity of the rat GLUT4/muscle-adipose glucose transporter gene product. 772 Jun 44

The temporal changes in the expression of fibronectin and other extracellular matrix genes were studied in rat aortic rings incubated in vitro in a serum-free medium. Changes in all forms of fibronectin mRNA increased progressively during the 24-hour incubation period, although an increase in the alternatively spliced form of fibronectin designated EIIIA was most pronounced. Both collagen and elastin mRNA levels decreased markedly during the 24-hour interval, as did alpha-actin mRNA. The increase in the relative amount of the EIIIA isoform after a 24-hour incubation was also shown using ribonuclease protection assays. In situ hybridization showed the distribution of the induced fibronectin mRNA to be within all cell types, including endothelial cells, medial smooth muscle cells, and adventitial fibroblasts. Localization in the media was not uniform and was clearly identified mainly in clusters of cells distributed throughout the media. The early induction of fibronectin mRNA was inhibited by genistein, implicating tyrosine kinase activation as a causative factor in fibronectin expression. The in vitro changes reported may reflect a phenotypic change in vascular cell types that is both similar to and different from the changes reported in vivo under conditions in which vascular injury and repair occur.
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PMID:Selective induction of an embryonic fibronectin isoform in the rat aorta in vitro. 837 Jan 23

The RNase protection assay was applied to quantify mRNA expression of five principal mammalian water channels in 18 different rat tissues, and to determine the influence of dehydration on renal water channel expression. Probes consisted of labeled cRNAs transcribed from cDNA fragments of rat CHIP28 (AQP-1, bp 238-575 of coding sequence), AQP-CD (AQP2, bp 53-606), MIWC (AQP4, bp 235-572), GLIP (AQP3, bp 219-604), and AQP5 (bp 56-612). Results were normalized to expression of rat beta-actin by quantitative densitometry of autoradiograms. CHIP28 mRNA was expressed strongly in heart, kidney > placenta, skeletal muscle, and urinary bladder and detected weakly in eye, lung, trachea, spleen, liver, colon, prostate, and skin. AQP-CD was detected only in kidney. MIWC mRNA expression was highest in brain, followed by eye, trachea, lung, stomach, kidney, and skeletal muscle. GLIP was found in eye, trachea, kidney, urinary bladder, skin, prostate, placenta, and skeletal muscle. AQP5 was detected in salivary gland, eye, lung, and trachea. An alternatively spliced form of MIWC (sMIWC) was also identified in lung and kidney by RNase protection assay, corresponding to deletion of exon 2 of MIWC. In response to dehydration (3 days, -15 % body weight), renal expression of CHIP28 and MIWC were unchanged, whereas expression of AQP-CD and GLIP were increased significantly by 2.18 +/- 0.04 and 1.36 +/- 0.11 fold (SE, n = 5), respectively. These results establish quantitative values for aquaporin transcript expression in multiple mammalian tissues. The sensitive RNase protection assay revealed the expression of water channels in several tissues not studied previously or in which mRNA levels were too low to detect by Northern blot analysis. The observation of GLIP up-regulation in kidney by dehydration suggests a role in the urinary concentrating mechanism.
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PMID:Quantitative analysis of aquaporin mRNA expression in rat tissues by RNase protection assay. 867 43

B7 molecules (CD80 (B7-1) and CD86 (B7-2/B70)) on APCs provide costimulatory signals for T cell proliferation. We previously described the presence of an alternatively spliced form of murine CD80 (previously termed MB7-2 and renamed as B7-1a) that completely lacks the second Ig-like domain coded by exon 3 in activated murine B cells. in this study, we first examined whether B7-1a mRNA can be detected in vivo by RNase protection assay. The expression of B7-1a mRNA was only detected in lymphoid organs although the level of expression was lesser than that of CD80 mRNA. However, we demonstrated that the expression of B7-1a mRNA like CD80 mRNA was considerably augmented in spleen cells treated with either LPS in vitro or OVA/CFA conjugate in vivo. We next determined the functional activity of B7-1a using Chinese hamster ovary (CHO) cells transfected by B7 genes. When resting T cells were cocultured with CHO cells expressing B7-1a molecules in the presence of PMA/ionomycin, T cell proliferation was not detected, while CHO cells either expressing CD80 or CD86 could promote the proliferation of resting T cells. in contrast to resting T cells, CHO cells expressing B7-1a could support the proliferation of activated T cells. Thus, costimulatory activity of B7-1a molecules was dependent upon the activation stage of T cells. Therefore the IgV-like region of CD80 contains a critical region for functional interaction with its ligands and can transduce a costimulatory signal for T cell proliferation.
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PMID:The role of the B7-1a molecule, an alternatively spliced form of murine B7-1 (CD80), on T cell activation. 875 5

RT-PCR was used to examine the expression of LAR (encoding the leukocyte-common antigen-related protein tyrosine phosphatase) in normal human colon mucosa, and colon polyps and tumors. Although the LAR protein was not detected in the colon in a previous immunohistochemical study, amplification of a region of LAR between the most membrane proximal (eighth) fibronectin type-III (FN-III) repeat and the transmembrane domain demonstrated LAR expression in all samples, but showed no difference in expression within matched samples from each patient examined. An additional minor fragment amplified in all reactions was consistently observed in colon and various cell line samples using this and two other LAR-specific sets of primers. Cloning and sequencing of the fragment identified it as deriving from a novel alternatively spliced form of LAR containing a retained intron of 85 bp. This intron encodes an additional 13 amino acids followed by an in-frame stop codon, thus its retention is predicted to give rise to a secreted LAR extracellular region isoform(s). LAR transcripts containing the intron were detected by RNase protection assay of colon samples and were present in most human tissues examined by Northern analysis. A protein in colon tumor extract was recognized by antiserum raised to the intron-encoded sequence. Soluble isoforms of the LAR extracellular immunoglobulin (Ig)-like/FN-III repeat-containing region could have a biological function distinct from those isoforms localized at the cell surface and/or coupled to intracellular phosphatase activity.
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PMID:Novel alternative splicing predicts a secreted extracellular isoform of the human receptor-like protein tyrosine phosphatase LAR. 891 69

A new murine member of the interferon (IFN)-inducible guanylate-binding protein (GBP) family was cloned in a search for glucocorticoid-attenuated response genes induced in the lung during endotoxemia. The full-length MuGBP-5 cDNA encodes a 590 amino acid residue protein with GTP binding motifs identical to those in human GBP-1 (HuGBP-1) and a similar isoprenylation sequence at the C-terminus. An alternatively spliced form of MuGBP-5 that lacks the second GTP binding motif and differs at the C-terminus was also identified. The MuGBP-5 gene is located on chromosome 3, near MuGBP-3 and MuGBP-2, and has a genomic organization similar to other GBP genes. To facilitate the evaluation of GBP family message expression, we constructed RNase protection assay probes for MuGBP-1, MuGBP-2, MuGBP-3, MuGBP-4/Mag-2 (macrophage activation gene-2), and MuGBP-5 and validated their use in Swiss Webster, BALB/c, and C57BL/6 mice. In BALB/c mice, all five MuGBPs were induced in multiple organs during endotoxemia, and all had a similar pattern of expression in different tissues. With minor quantitative differences, the MuGBPs also had similar patterns of response to IFN-gamma, lipopolysaccharide (LPS), interleukin-1beta (IL-1beta), and tumor necrosis factor-alpha (TNF-alpha) in RAW 264.7 and Swiss 3T3 cells. The coordinate expression of the MuGBPs suggests that they share common mechanisms of regulation.
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PMID:Murine GBP-5, a new member of the murine guanylate-binding protein family, is coordinately regulated with other GBPs in vivo and in vitro. 1239 30

We exploited Jurkat leukemia T cell clone E6-1 as a model of Trichostatin A (TSA) effect on cellular levels of ZAP-70, LAT and SLP-76 molecules involved in the signal transduction pathway from T cell receptor to nucleus. Using reverse transcription real-time quantitative PCR and Western blotting analysis we observed that TSA resulted in ZAP-70, LAT and SLP-76 transcript and protein down-regulation in Jurkat leukemia T cells. We also found that TSA reduced half-life of ZAP-70, LAT and SLP-76 mRNAs from 4.8, 3.5, and 4.8 to approximately 2.3, 1.9 and 1.7 h, respectively. Employing the protein biosynthesis inhibitor cycloheximide, we demonstrated the involvement of RNase and/or mRNA stabilization protein in ZAP-70, LAT and SLP-76 mRNAs stabilization. The effect of TSA on ZAP-70, LAT and SLP-76 content in T cells confirms an immunosuppressive effect by TSA, and the usefulness of this histone deacetylase inhibitor in the treatment of autoimmune diseases.
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PMID:Trichostatin A down-regulates ZAP-70, LAT and SLP-76 content in Jurkat T cells. 1717 87