RGD Reference Report - Cloning of rat 17 beta-hydroxysteroid dehydrogenase type 2 and characterization of tissue distribution and catalytic activity of rat type 1 and type 2 enzymes. - Rat Genome Database

Send us a Message



Submit Data |  Help |  Video Tutorials |  News |  Publications |  Download |  REST API |  Citing RGD |  Contact   

Cloning of rat 17 beta-hydroxysteroid dehydrogenase type 2 and characterization of tissue distribution and catalytic activity of rat type 1 and type 2 enzymes.

Authors: Akinola, LA  Poutanen, M  Vihko, R 
Citation: Akinola LA, etal., Endocrinology 1996 May;137(5):1572-9.
RGD ID: 728619
Pubmed: PMID:8612487   (View Abstract at PubMed)
DOI: DOI:10.1210/endo.137.5.8612487   (Journal Full-text)

17 beta-Hydroxysteroid dehydrogenases (17HSDs) are enzymes catalyzing the conversion between 17 beta-hydroxy- and 17-ketosteroids. Both estrogens and androgens possess their highest activity in the 17 beta-hydroxy form, and the enzymes, therefore, regulate the biological activity of sex hormones. In this study, we have characterized the complementary DNA (cDNA) for rat 17HSD type 2. The cDNA encodes a protein with a predicted mol wt of 42,010 Da. The protein has 77% similarity and 62% identity with the human 17HSD type 2 enzyme. Furthermore, the hydropathicity profiles of the enzymes are very similar. The two isozymes contain a putative transmembrane region close to the N-terminus. However, the rat isozyme lacks the two lysine-rich amino acid cluster present at the N- and C-terminals of human 17HSD type 2. The tissue distribution of the rat 17HSD type 1 and type 2 enzymes is very similar to that of the human enzymes. The highest expression of 17HSD type 2 was detected in the placenta. In addition, a 1.5-kilobase messenger RNA for the enzyme was detected in the small intestine, liver, and kidney of both sexes. The two messenger RNAs for rat 17HSD type 1 (1.4 and 1.7 kilobases) were highly expressed only in the ovary, and at very low concentrations in the kidney of both sexes. Transiently expressed rat 17HSD type 2 showed oxidative activity almost exclusively in cultured human embryonic kidney 293 cells, converting estradiol into estrone and testosterone into androstenedione, whereas the opposite was observed for the rat type 1 enzyme. The data suggest that similarly to the corresponding human isoforms, rat 17HSD type 2 is mostly involved in the oxidation of 17 beta-hydroxysteroids into their relatively inactive keto derivative in peripheral tissues, whereas rat 17HSD type 1 is mainly involved in the glandular biosynthesis of estradiol.

Gene Ontology Annotations    Click to see Annotation Detail View

Biological Process
TermQualifierEvidenceWithReferenceNotesSourceOriginal Reference(s)
androgen biosynthetic process  IDA 728619androstenedioneRGD 
estrogen biosynthetic process  IDA 728619estradiolRGD 
estrogen biosynthetic process  IDA 728619estroneRGD 
testosterone biosynthetic process  IDA 728619 RGD 

Molecular Function
TermQualifierEvidenceWithReferenceNotesSourceOriginal Reference(s)
estradiol 17-beta-dehydrogenase [NAD(P)] activity  IDA 728619; 728619 RGD 
testosterone dehydrogenase (NAD+) activity  IDA 728619; 728619 RGD 

Objects Annotated

Genes (Rattus norvegicus)
Hsd17b1  (hydroxysteroid (17-beta) dehydrogenase 1)
Hsd17b2  (hydroxysteroid (17-beta) dehydrogenase 2)


Additional Information