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)

The rat beta-galactoside alpha 2,6-sialytransferase gene is differentially utilized by liver and kidney in the generation of mRNAs that predict substantially divergent polypeptides. In order to determine the biosynthetic relationship between these sialyltransferase mRNA isoforms, genomic sequences were isolated and analysed. Five exons that span at least 40 kb of DNA carry the coding information for the liver beta-galactoside alpha 2,6-sialyltransferase protein. An additional exon contains only sequences for the 5'-untranslated leader of the liver mRNA. In contrast, the predominant kidney mRNAs from this gene share only three coding exons that specify the carboxyl terminal 42% of the liver sialyltransferase protein sequence. In addition, these kidney mRNAs contain information from two other exons that comprise the 5' divergent region of these transcripts. Primer extension and S1 nuclease protection analysis demonstrate that the hepatic and kidney specific mRNAs are transcriptionally initiated at different sites within the sialyltransferase gene. While the hepatic sialyltransferase mRNAs are transcribed from the first exon, the kidney transcripts are initiated from a site within the third intron. Genomic regions upstream of both transcriptional initiation sites can regulate expression of the bacterial chloramphenicol acetyltransferase gene in transiently transfected L cells. Together, the data implicate multiple promoters as a principle mechanism in the generation of kidney and liver gene product diversity in sialyltransferase expression.
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PMID:Rat beta-galactoside alpha 2,6-sialyltransferase genomic organization: alternate promoters direct the synthesis of liver and kidney transcripts. 198 83

The beta-galactoside alpha-2,6-sialyltransferase represents a member of a family of sialyltransferases which catalyze the terminal addition of sialic acid to maturing carbohydrate chains. We surveyed rat tissues using cDNA probes complementary to coding and noncoding domains of the rat liver alpha-2,6-sialyltransferase. In addition to the expected differences in the level of sialyltransferase mRNA among the tissues, there were dramatic qualitative differences as well. Hepatic sialyltransferase probes hybridize to mRNAs of varying size on Northern blots. A tissue-dependent pattern of expression of these transcripts is documented. Evidence is presented that the multiple transcripts are generated from a common gene sequence. At least one instance of alternate splicing in the generation of the kidney sialyltransferase transcripts is predicted by S1 nuclease analysis. We report the isolation of a rat kidney cDNA clone, RKA, that substantiates this tissue-specific alternate splicing event. The RKA insert, although less than full-length, apparently encodes a polypeptide divergent from the reported hepatic alpha-2,6-sialyltransferase (1). RNA blot analysis indicates that the RKA-type transcripts represent a significant proportion of sialyltransferase RNA in rat kidney. Another class of kidney cDNA clones, RKE, is colinear with the hepatic sialyltransferase sequence. RNA blots probed for the divergent and common regions suggest that complex processing pathways are operative in the tissue-specific expression of sialyltransferase mRNA.
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PMID:Tissue-specific expression of beta-galactoside alpha-2,6-sialyltransferase. Transcript heterogeneity predicts a divergent polypeptide. 279 63

cDNA and genomic clones encoding mouse Galbeta1, 3GalNAc-specific GalNAc alpha2,6-sialyltransferase (ST6GalNAc II) were isolated, and the structure organization of the gene was determined. The predicted amino acid sequence is 57.4% identical to the chick ST6GalNAc II sequence but 33.8% identical to the chick ST6GalNA I (GalNAc alpha2, 6-sialyltransferase) sequence. The ST6GalNAc II gene is constitutively expressed in various mouse tissues but highly expressed in lactating mammary gland and adult testis. The gene contains nine exons spanning about 25 kilobases of genomic DNA and encodes a messenger RNA of 1995 nucleotides. Primer extension and S1 nuclease protection analysis of submaxillary gland mRNA showed that the transcription of the ST6GalNAc II gene starts from 68 nucleotides upstream from the translation start site. Characterization of 5'-flanking genomic regions indicated that the Galbeta1,3GalNAc-specific GalNAc alpha2,6-sialyltransferase promoter is embedded in a G+C-rich domain and contains no TATA or CAAT box but has putative binding sites for transcription factors Sp1 and AP-2. Transient transfection experiments involving luciferase reporter genes demonstrated promoter activity in NIH3T3 cells.
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PMID:Molecular cloning and genomic analysis of mouse Galbeta1, 3GalNAc-specific GalNAc alpha2,6-sialyltransferase. 866 27

The mouse Sia alpha 2,3Gal beta 1, 4GalNAc alpha 2,8-sialyltransferase (ST8Sia III) genomic gene, whose transcripts are only expressed in fetal and newborn brain and testis, was isolated and its 5'-flanking region was analyzed. The gene was found to span about 8 kb and to be composed of only four exons. The genomic ST8Sia III gene is much smaller and its organization much simpler than other sialyltransferase genes so far reported, which span more than 25 kb and comprise seven or more exons. In particular, the sialyl motif L of ST8Sia III, which is a highly conserved region in all cloned sialyltransferases, was in one exon. In contrast, this motif is encoded by discrete exons in the other sialyltransferases. The ST8Sia III gene was highly expressed in the mouse brain and gave rise to at least three transcripts (2.1 kb, 2.4 kb, and 6.5 kb), which differed in the length of their 3'-untranslated regions through the alternative use of different polyadenylation sites. Primer extension and S1 nuclease protection analyses of mRNA prepared from newborn brain revealed that ST8Sia III gene expression started from a unique site at 382 nt upstream of ATG. Although the promoter region lacked an apparent TATA or CCAAT box and potential regulatory motifs, a transfection experiment involving neuroblastoma cells expressing ST8Sia III demonstrated the minimal promoter activity exhibited by the proximal region 418 bp upstream from the ATG codon, which suggests the presence of tissue-specific enhancer elements.
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PMID:Unique genomic structure and expression of the mouse alpha 2,8-sialyltransferase (ST8Sia III) gene. 892 52