Back to Search
Start Over
Human 3α-hydroxysteroid dehydrogenase type 3: structural clues of 5α-DHT reverse binding and enzyme down-regulation decreasing MCF7 cell growth
- Source :
- Biochemical Journal. 473:1037-1046
- Publication Year :
- 2016
- Publisher :
- Portland Press Ltd., 2016.
-
Abstract
- Human 3α-HSD3 (3α-hydroxysteroid dehydrogenase type 3) plays an essential role in the inactivation of the most potent androgen 5α-DHT (5α-dihydrotestosterone). The present study attempts to obtain the important structure of 3α-HSD3 in complex with 5α-DHT and to investigate the role of 3α-HSD3 in breast cancer cells. We report the crystal structure of human 3α-HSD3·NADP+·A-dione (5α-androstane-3,17-dione)/epi-ADT (epiandrosterone) complex, which was obtained by co-crystallization with 5α-DHT in the presence of NADP+. Although 5α-DHT was introduced during the crystallization, oxidoreduction of 5α-DHT occurred. The locations of A-dione and epi-ADT were identified in the steroid-binding sites of two 3α-HSD3 molecules per crystal asymmetric unit. An overlay showed that A-dione and epi-ADT were oriented upside-down and flipped relative to each other, providing structural clues for 5α-DHT reverse binding in the enzyme with the generation of different products. Moreover, we report the crystal structure of the 3α-HSD3·NADP+·4-dione (4-androstene-3,17-dione) complex. When a specific siRNA (100 nM) was used to suppress 3α-HSD3 expression without interfering with 3α-HSD4, which shares a highly homologous active site, the 5α-DHT concentration increased, whereas MCF7 cell growth was suppressed. The present study provides structural clues for 5α-DHT reverse binding within 3α-HSD3, and demonstrates for the first time that down-regulation of 3α-HSD3 decreases MCF7 breast cancer cell growth.
- Subjects :
- 0301 basic medicine
Down-Regulation
Dehydrogenase
Plasma protein binding
Epiandrosterone
Biology
Biochemistry
Protein Structure, Secondary
03 medical and health sciences
3-alpha-Hydroxysteroid Dehydrogenase (B-Specific)
0302 clinical medicine
X-Ray Diffraction
Oxidoreductase
Humans
Binding site
Molecular Biology
chemistry.chemical_classification
Binding Sites
Cell growth
Dihydrotestosterone
Cell Biology
Growth Inhibitors
030104 developmental biology
Enzyme
chemistry
030220 oncology & carcinogenesis
MCF-7 Cells
Crystallization
Protein Binding
Subjects
Details
- ISSN :
- 14708728 and 02646021
- Volume :
- 473
- Database :
- OpenAIRE
- Journal :
- Biochemical Journal
- Accession number :
- edsair.doi.dedup.....6d1dcdf559700f223e9c84a66918ec1c