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)

A mutation in the gene IRA1 (formerly called PPD1) was originally characterized as a deficiency of a phosphoprotein phosphatase. The IRA1 gene has been cloned and sequenced. A large open reading frame (8,817 base pairs) which can encode a protein of 2,938 amino acids was found. Northern (RNA) blot analysis detected a message of about 10 kilobases, and nuclease S1 protection demonstrated mRNA start points at 97 and 98 base pairs upstream from the putative initiator ATG codon. Disruption of the IRA1 gene resulted in sensitivity to nitrogen starvation and heat shock. Diploids homozygous for the disrupted IRA1 gene were deficient in sporulation. Disruption of the IRA1 gene suppressed the lethality of the cdc25 mutation but did not suppress the lethality of either the ras1 ras2 or the cyr1 mutations. Deficiency of the phosphoprotein phosphatase was not reproducible in the disruption mutant of the IRA1 gene. Moreover, the ira1 mutant showed an increased level of cyclic AMP. Our results suggest that the IRA1 protein inhibits the function of the RAS proteins in a fashion antagonistic to the function of the CDC25 protein in the RAS-cyclic AMP pathway in Saccharomyces cerevisiae.
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PMID:IRA1, an inhibitory regulator of the RAS-cyclic AMP pathway in Saccharomyces cerevisiae. 254 Apr 26

The human adenosine deaminase cDNA has been cloned in a lambda-vector. Contained within a sequence of over 1500 nucleotides is an open reading frame of 1089 nucleotides that encodes the amino acids of ADA. The functional ADA gene contains at least six kilobases and has at least two introns. Using in vitro translation, molecular hybridization to ADA cDNA, and S1 nuclease mapping, ADA mRNA has been characterized in lymphoblast lines from seven different ADA-deficient children. All of the lines contain substantial amounts of RNA, which hybridizes specifically to the ADA cDNA. Four of the cell lines contain translatable mRNAs with small defects such as single base substitutions that are not detectable by S1 mapping. Deficiency of ADA activity in these lines appears secondary to synthesis of structurally altered proteins containing simple amino acid substitutions. Three of the lines contain mRNAs with S1 nuclease detectable defects. Some or all of these defective mRNAs are postulated to result from anomalous RNA processing. In these cases the causes of the ADA deficiency may be more complex than simple amino acid substitutions in the protein and could include small insertions or deletions of amino acids as well as changes in the efficiency of translation of the mRNAs.
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PMID:Molecular biology of the adenosine deaminase gene and messenger RNA. 386 73