SEQUENCE OF MOUSE 17-BETA-HYDROXYSTEROID DEHYDROGENASE TYPE-3 CDNA AND TISSUE DISTRIBUTION OF THE TYPE-1 AND TYPE-3 ISOFORM MESSENGER-RNAS

The enzyme 17 beta-hydroxysteroid dehydrogenase (17 beta HSD) intercon verts 17-ketosteroids and 17 beta-hydroxysteroids. Five isoforms of th e enzyme have been identified in the human, two of which (types 1 and 3) have been shown to catalyse the reduction reaction preferentially. The cDNA encoding mouse 17 beta HSD type 3 was isolated from testis cD NA using the RACE technique and primers based on the human sequence. T he mouse protein is 305 amino acids in length which is five short of t he human protein with four of these amino acids missing at the N-termi nus. The predicted amino acid sequence is 72.5% identical and 94.8% si milar to the human sequence. Tissue distribution of mRNA encoding both types 1 and 3 17 beta HSD was studied using reverse transcription and the polymerase chain reaction (RT-PCR). Highest levels of type 1 mRNA were found in the ovary whereas highest levels of type 3 were in the testis. All other tissues tested contained mRNA encoding both isoforms of the enzyme although levels were markedly lower than in the gonads. Copyright (C) 1997 Published by Elsevier Science Ltd.