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

Previously, we identified a novel human cytochrome P450 cDNA that is inducible by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and represents the first member of a new subfamily designated cytochrome P4501B1 (CYP1B1; Sutter, T. R., Tang, Y. M., Hayes, C. L., Wo, Y. P., Jabs, E. W., Li, X., Yin, H., Cody, C. W., and Greenlee, W. F. (1994) J. Biol. Chem. 269, 13092-13099). Here, we report on the isolation and initial characterization of the CYP1B1 gene. The CYP1B1 gene maps to human chromosome 2 at 2p21-22 and contains three exons and two introns. The putative open reading frame starts in the second exon and is 1629 base pairs in length. Southern analysis using DNA probes directed to each of the three exons confirmed that CYP1B1 is a single copy gene. Human CYP1B1 differs from its two most closely related members of the cytochrome P450 superfamily, CYP1A1 and CYP1A2, in the number of exons (3 versus 7) and chromosome location (2 versus 15). A single transcription initiation site was identified by primer extension analysis and S1 nuclease mapping. Based on nucleotide sequence analysis, the CYP1B1 gene lacks a consensus TATA box in the promoter region and contains nine TCDD-responsive enhancer core binding motifs (5'-GCGTG-3') located within a 2.5-kilobase pair genomic fragment 5'-ward of the transcription initiation start site. Deletion analysis of chloramphenicol acetyltransferase reporter gene constructs containing 5' CYP1B1 genomic fragments indicates that a region from -1022 to -835 containing three of the nine core binding motifs contributes to the TCDD-inducible expression of CYP1B1.
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PMID:Isolation and characterization of the human cytochrome P450 CYP1B1 gene. 891 Apr 54

Complementary DNA of marmoset CYP1A2 was isolated by means of screening the cDNA library and reverse-transcriptase polymerase chain reaction. The deduced amino acid sequence of marmoset CYP1A2 consisted of 516 residues and showed 88.2 and 90.0% identities to corresponding forms in human and cynomolgus monkey, respectively. S1 nuclease protection assay demonstrated that CYP1A2 mRNA was expressed constitutively in the liver, but not in the lung, kidney and small intestine. The level of CYP1A2 mRNA in the liver was increased by treatment with 3-methylcholanthrene and polychlorinated biphenyls. Marmoset CYP1A2 expressed in recombinant yeast activated 2-amino-3-methylimidazo [4,5-f]quinoline (IQ) and 2-amino-3,8-dimethylimidazo [4,5-f]quinoxaline (MeIQx) efficiently, and also activated 2-amino-1-methyl-6-phenylimidazo [4,5-b]pyridine (PhIP), but at a relatively lower rate in the umu mutagenicity test. Marmoset CYP1A2 also showed ethoxyresorufin O-de-ethylase activity. Based on these results, we demonstrate that marmosets constitutively express CYP1A2 in the liver as in humans.
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PMID:Marmoset CYP1A2: primary structure and constitutive expression in livers. 936 10