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)

Fatty acid synthase is regulated by diet and hormones, with regulation being primarily transcriptional. In chick embryo hepatocytes in culture, triiodothyronine stimulates accumulation of enzyme and transcription of the gene. Since the 5'-flanking region of this gene is likely involved in hormonal regulation of its expression, we have isolated and partially characterized an avian fatty acid synthase gene. A genomic DNA library was constructed in a cosmid vector and screened with cDNA clones that contained sequence complementary to the 3' end of goose fatty acid synthase mRNA. A genomic clone (approximately 35 kilobase pairs (kb] was isolated, and a 6.5-kb EcoRI fragment thereof contained DNA complementary to the 3' noncoding region of fatty acid synthase mRNA. Additional cosmid libraries were screened with 5' fragments of previously isolated genomic clones, resulting in the isolation of five overlapping cosmid DNAs. The entire region of cloned DNA spans approximately 105 kb. Exon-containing fragments were identified by hybridization with end-labeled poly(A)+ RNA and by hybridization of labeled exon-containing genomic DNA fragments to fatty acid synthase mRNA. A new set of cDNA clones spanning approximately 3.2 kb was isolated from a lambda-ZAP goose liver cDNA library using the 5'-most exon-containing fragment of the 5'-most genomic DNA clone. This region of mRNA contains a 5'-untranslated sequence and a continuous open reading frame which includes a region that codes for the essential cysteine of the beta-ketoacyl synthase domain. The entire fatty acid synthase gene spans about 50 kb. The 5' 15 kb of the gene contain 7 exons. S1 nuclease and primer extension analyses were used to identify a single site for initiation of transcription, 174 nucleotides upstream from the putative translation initiation codon. Putative "TATA" and "CCAAT" boxes are located 28 and 60 base pairs (bp), respectively, upstream of the site of initiation of transcription. The 5'-flanking 597 bp of DNA contains G/C-rich sequences including several "GC" boxes corresponding to binding sites for the nuclear transcription factor Sp1. Putative sites for AP-2, C/EBP, and the triiodothyronine and glucocorticoid receptors also were found in this region. A chimeric DNA, containing approximately 1.6 kb of 5'-flanking sequence and 139 bp of untranslated sequence of the goose fatty acid synthase gene ligated to the bacterial chloramphenicol acetyl-transferase (CAT) gene, was transfected into chick embryo hepatocytes in culture. Cells treated with triiodothyronine contained increased chloramphenicol acetyltransferase and fatty acid synthase activities.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Isolation and partial characterization of the gene for goose fatty acid synthase. 170 26

Rat genomic clones encompassing the entire fatty acid synthase gene have been isolated and characterized. The gene is present in a single copy of approx. 20 kb. Genomic DNA sequencing, direct RNA sequencing and S1 nuclease analysis showed that transcription is initiated primarily 1274 nucleotides upstream from the translation start site and that the 87-nucleotide-long 5'-untranslated mRNA sequence is the same in liver, lung and mammary gland. The 5'-flanking region and first intron contain several sequence elements which may be involved in the transcriptional regulation of this gene.
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PMID:Molecular cloning of the mammalian fatty acid synthase gene and identification of the promoter region. 224 72

The fatty acid synthase (FAS) of animal tissue is a dimer of two identical subunits, each with a Mr of 260,000. The subunit is a single multifunctional protein having seven catalytic activities and a site for binding of the prosthetic group 4'-phosphopantetheine. The mRNA coding for the subunit has an estimated size of 10-16 kb, which is about twice the number of nucleotides needed to code for the estimated 2300 amino acids. We have isolated a positive clone, lambda CFAS, containing FAS gene sequences by screening a chicken genomic library with a segment of a 3' untranslated region of goose fatty acid synthase cDNA clone, pGFAS3, as a hybridization probe. The DNA insert in lambda CFAS hybridizes with synthetic oligonucleotide probes prepared according to the known amino acid sequence of the thioesterase component of the chicken liver fatty acid synthase [Yang, C.-Y., Huang, W.-Y., Chirala, S., & Wakil, S.J. (1988) Biochemistry (preceding paper in this issue)]. Further characterization of the DNA insert shows that the lambda CFAS clone contains about a 4.7-kbp segment from the 3' end of the chicken FAS gene that codes for a portion of the thioesterase domain. Complete sequence analyses of this segment including S1 nuclease mapping, showed that the lambda CFAS clone contains the entire 3' untranslated region of the chicken FAS gene and three exons that code for 162 amino acids of the thioesterase domain from the COOH-terminal end of the fatty acid synthase. Using the exon region of the genomic clone, we were able to isolate a cDNA clone that codes for the entire thioesterase domain of chicken liver fatty acid synthase.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Characterization of a genomic and cDNA clone coding for the thioesterase domain and 3' noncoding region of the chicken liver fatty acid synthase gene. 320 10