Mammalian 3 alpha-hydroxysteroid dehydrogenases.
Steroids
; 61(9): 508-23, 1996 Sep.
Article
in En
| MEDLINE
| ID: mdl-8883217
ABSTRACT
Mammalian 3 alpha-hydroxysteroid dehydrogenases (3 alpha-HSDs) regulate steroid hormone levels. For example, hepatic 3 alpha-HSDs inactivate circulating androgens, progestins, and glucocorticoids. In target tissues they regulate access of steroid hormones to steroid hormone receptors. For example, in the prostate 3 alpha-HSD acts as a molecular switch and controls the amount of 5 alpha-dihydrotestosterone that can bind to the androgen receptor, while in the brain 3 alpha-HSD can regulate the amount of tetrahydrosteroids that can alter GABAa receptor function. Molecular cloning indicates that these mammalian 3 alpha-HSDs belong to the aldo-keto reductase superfamily and that they are highly homologous proteins. Using the three-dimensional structure of rat liver 3 alpha-HSD as a template for site-directed mutagenesis, details regarding structure function relationships, including catalysis and cofactor and steroid hormone recognition have been elucidated. These details may be relevant to all mammalian 3 alpha-HSDs.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
3-Hydroxysteroid Dehydrogenases
Type of study:
Prognostic_studies
Limits:
Animals
/
Humans
/
Male
Language:
En
Journal:
Steroids
Year:
1996
Type:
Article
Affiliation country:
United States