title: Characterization of 17 beta-hydroxysteroid dehydrogenase IV.
abstract: 17 beta-Hydroxysteroid dehydrogenase (17 beta-HSD) IV is coded by 2.9 kb mRNA translated to an 80 kDa protein which is N-terminally cleaved to a 32 kDa enzyme. The 17 beta-HSD IV is dedicated to steroid inactivation and reveals only 25% amino acid similarity with 17 beta-HSD I-III enzymes. Despite five Asn-Xaa-Ser/Thr (Xaa = unspecified amino acid) sites in the 80 kDa protein the enzyme is not glycosylated. The porcine 32 kDa 17 beta-HSD IV forms dimers of 75 kDa. The highest 17 beta-HSD IV mRNA expression and specific activities are found in liver and kidney followed by ovary and testes. In porcine gonads the immunofluorescence assigned the 17 beta-HSD IV to granulosa cells and to Leydig and Sertoli cells. As shown by the treatment with phorbol-myristate-acetate in vitamin D-differentiated monocytic leukemia THP1 cells, steroid synthesis and inactivation are regulated differentially by the protein kinase C pathway: an increase in aromatase is accompanied by a decrease in 17 beta-HSD IV mRNA levels.
authors.affiliation: Max-Planck-Institut für Experimentelle Endokrinologie, Hannover, Germany.
authors.forename: J F
authors.initials: JF
authors.lastname: Carstensen
authors.forename: J G
authors.initials: JG
authors.lastname: Tesdorpf
authors.forename: M
authors.initials: M
authors.lastname: Kaufmann
authors.forename: M M
authors.initials: MM
authors.lastname: Markus
authors.forename: B
authors.initials: B
authors.lastname: Husen
authors.forename: F
authors.initials: F
authors.lastname: Leenders
authors.forename: F
authors.initials: F
authors.lastname: Jakob
authors.forename: Y
authors.initials: Y
authors.lastname: de Launoit
authors.forename: J
authors.initials: J
authors.lastname: Adamski
mesh_terms: D015067:17-Hydroxysteroid Dehydrogenases / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D015152:Blotting, Northern; D002460:Cell Line; D019281:Dimerization; D004960:Estradiol Dehydrogenases / Q000378:metabolism; D005260:Female; D006031:Glycosylation; D006801:Humans; D007668:Kidney / Q000196:embryology / Q000201:enzymology; D008297:Male; D051379:Mice; D008969:Molecular Sequence Data; D010053:Ovary / Q000201:enzymology; D013552:Swine; D013737:Testis / Q000201:enzymology
chemical_list: D015067:17-Hydroxysteroid Dehydrogenases; D004960:Estradiol Dehydrogenases