Reactome | CYP17A1 cleaves 17aHPREG to DHA

CYP17A1 cleaves 17aHPREG to DHA

Stable Identifier

R-HSA-193070

Type

Reaction [transition]

Species

Homo sapiens

Compartment

cytosol, endoplasmic reticulum membrane

Synonyms

Side chain cleavage of 17alpha-hydroxypregnenolone to yield DHA, 17alpha-hydroxyprenenolone + NADPH + H+ + O2 => DHA (dehydroepiandrostenedione) + NADP+ + H2O + acetaldehyde

ReviewStatus

5/5

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17-alpha-hydroxypregnenolone, NADPH + H+, and O2 react to form DHA (dehydroepiandrostenedione), NADP+, H2O, and acetaldehyde. CYP17 (which also catalyzes 17-alpha-hydroxylation) catalyzes this lyase reaction. There are marked species differences in which substrate is used for this lyase activity. The human enzyme prefers 17alpha-pregnenolone (delta5 steroid) as substrate (Brock, BJ, Waterman, MR, 1999). Corticotropin (Adrenocorticotropic hormone, ACTH) acts through the ACTH receptor called melanocortin receptor type 2 (MC2R) to stimulate steroidogenesis, increasing the production of androgens (McKenna et al, 1997).

Literature References

PubMed ID	Title	Journal	Year
9536209	A critical review of the origin and control of adrenal androgens Fearon, U, Clarke, D, McKenna, TJ, Cunningham, SK	Baillieres Clin Obstet Gynaecol	1997
10406467	Molecular modeling of human P450c17 (17alpha-hydroxylase/17,20-lyase): insights into reaction mechanisms and effects of mutations Miller, WL, Auchus, RJ	Mol Endocrinol	1999