Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.30.1 (S1 nuclease)
 3,660 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Changes in insulin-regulated gene expression occur in a time- and tissue-dependent fashion. To monitor these changes we have adapted the S1 nuclease protection assay to allow simultaneous estimation of multiple RNA species in a single sample by using synthetic oligonucleotides of various lengths as probes for specific RNA species, which can then be resolved by electrophoresis. The multiple S1 nuclease protection assay was used to assess the influence of insulin on the RNA concentrations of 12 different genes in human skeletal muscle. Estimates obtained by this assay were comparable with those obtained by Northern analysis. RNA levels for proto-oncogene c-src displayed a transient 4-fold increase, whereas RNA levels for type 1 protein phosphatase were suppressed by 50% during the same time period. RNAs corresponding to known insulin-responsive genes such as c-fos, c-myc, c-Ha-ras, and c-src displayed rapid and transient 2-4-fold increases between 30 and 60 min as detected by either Northern analysis or the multiple S1 nuclease protection assay. In addition, RNA levels for the insulin receptor, Glut-4, Glut-3, and c-jun were apparently unaffected by exposure of the cells to insulin.
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PMID:Use of a multiple S1 nuclease protection assay to monitor changes in RNA levels for type 1 phosphatase and several proto-oncogenes in response to insulin. 137 96

Heterotrimeric G-proteins function as signal transducers for a variety of hormone-coupled enzyme and ion transport systems in eukaryotic cells. We have studied G-protein-coupled processes that appear to be developmentally regulated in polarized pig kidney cells (LLC-PK1). Following trypsinization, LLC-PK1 cells differentiate from a rounded cell type to a fully polarized epithelium by 7 days of culture. During this differentiation, the expression of G-protein alpha i-2 subunit mRNA was not detected until day 4 of culture, it peaked at day 6, and declined thereafter. In contrast, G-protein alpha s subunit mRNA which peaked on day 4 was easily detected on all culture days. The presence of the alpha i-2 protein on epithelial cell basolateral membranes followed the same pattern of mRNA expression during culture. To understand the developmental expression of the alpha i-2 subunit in non-polarized cells and its potential regulation by hormones and second messengers in polarized cells at the transcriptional level, genomic DNA segments encoding the alpha i-2 gene promoter were isolated from an EMBL-3 porcine genomic library. S1 nuclease analysis of LLC-PK1 mRNA with cRNA probes derived from these DNA segments revealed major and a minor transcriptional start sites 131 and 171 base pairs upstream of the translation initiation site. The porcine and human alpha i-2 subunit genes shared a 78% sequence identity in their 5' flanks which suggested an evolutionary conservation of cis elements required to influence their transcription. The porcine alpha i-2 gene promoter was identified by fusing DNA segments encoding putative 5'-flanking areas of the gene to a plasmid that contained a firefly luciferase reporter gene but lacked a promoter. The minimal promoter was found between -130 and -60 base pairs from the major transcription start site. No typical "TATA-like" sequences were found. However, a "GC" box and a "TGTGG" sequence were two potential cis elements required for basal transcription of the porcine gene promoter which shared a 76% sequence identity to the promoter of another GTP-binding protein, the human c-Ha-ras proto-oncogene. Transcription of the gene was inhibited following treatment of renal cells with 10(-8) M dexamethasone.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Regulation of the G-protein alpha i-2 subunit gene in LLC-PK1 renal cells and isolation of porcine genomic clones encoding the gene promoter. 189 94

In vivo short term (2 h) insulin-regulated gene expression was examined in skeletal muscle of persons with differing insulin sensitivities. Nine genes were analyzed by a S1 nuclease protection assay with multiple probes (multiple S1 nuclease protection assay) to allow the simultaneous examination of RNA abundances from the multiple genes. In insulin-sensitive individuals, 5 of these 9 genes were insulin responsive. RNA from the proto-oncogenes c-Ha-ras, c-myc, and c-src transiently increased 2- to 4-fold within 30 min of insulin infusion. In addition, the RNA abundance of myf-5, a muscle specific differentiation factor, increased 3-fold with a time course similar to that of c-Ha-ras, c-myc, and c-src. In contrast, type 1 protein phosphatase alpha (PPP1A) RNA levels decreased by 50% within 30 min. In insulin-resistant individuals, the RNA levels of c-Ha-ras and myf-5 did not increase, whereas c-src RNA did increase within 30 min of insulin infusion. RNA encoding c-myc transiently increased in both groups; however, this response was lower in insulin-resistant individuals than in insulin-sensitive individuals in a pattern similar to c-Ha-ras and myf-5. PPP1A RNA levels slightly increased in insulin-resistant individuals. In both insulin-sensitive and insulin-resistant persons, RNA quantities of GLUT4, c-jun, c-fos, and the insulin receptor did not change over the period of insulin infusion. However, overall RNA levels of the insulin receptor and c-jun were lower in insulin-resistant individuals.
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PMID:Insulin regulation of multiple ribonucleic acid species in human skeletal muscle in insulin-sensitive and insulin-resistant subjects. 863 61