The cDNA sequence and expression of a variant 17 beta-hydroxysteroid UDP-glucuronosyltransferase.

摘要: The cDNA encoding a member of family steroid UDP-glucuronosyltransferases has been cloned and sequenced. 1871-base pair (bp) cDNA, designated UDPGTr-5, contains an open reading frame 1590 bp flanked by 43 238 5'- 3'-untranslated regions, respectively. 530-amino acid protein encoded the is 93% 84% similar in sequence to UDPGTr-3 UDPGTr-4, which are other members this multigene family. In common with these forms, regions characteristic signal peptide transmembrane-anchoring domain at carboxyl terminus. Potential asparagine-linked glycosylation sites not present protein. Expression UDPGTr-5 COS cells demonstrated that enzyme subunit size 50 kDa as determined sodium dodecyl sulfate-polyacrylamide gel electrophoresis. expressed glucuronidates testosterone dihydrotestosterone, although its activity towards two substrates about 30-fold less than UDPGTr-3. This low appeared be bone fide property was due lower amounts synthesized or increased rates degradation. Northern analysis sequencing mRNA species differed lengths their regions. longer transcript 1768-bp region segment 80% rat identifier (ID) repetitive DNA elements. These data indicate another 17 beta-hydroxysteroid UDP-glucuronosyltransferase mRNAs transcribed from single gene.