Isolation, Sequence, and Developmental Expression of RatUGT2B2: The Gene Encoding a Constitutive UDP Glucuronosyltransferase That Metabolizes Etiocholanolone and Androsterone

摘要

ABSTRACTThe UDP glucoronosyltransferase geneUGT2B2is constitutively expressed in rat liver, and the enzyme has been shown to conjugate glucuronic acid with various endogenous steroids, especially etiocholanolone and androsterone. We have cloned and sequenced much of theUGT2B2gene and 5′-flanking (247 bp) and 3′-flanking (734 bp) regions. The gene contains six exons spanning about 15.3 kb. Translation begins at nucleotide 36 of exon 1 and terminates with 280 coding nucleotides into exon 6, encoding a protein of 530 amino acids (calculated Mrof the unmodified chain = 60,913). We have determined that theUGT2B2full-length cDNA is 1,974 bp. Northern hybridization revealed that the hepatic UGT2B2 transcript is detectable 4 days before birth, becomes markedly elevated in the neonate, and is even further increased at 3 and 12 weeks of age in the liver of both male and female r