Journal
SEMINARS IN REPRODUCTIVE MEDICINE
Volume 22, Issue 4, Pages 281-288Publisher
THIEME MEDICAL PUBL INC
DOI: 10.1055/s-2004-861545
Keywords
adrenal gland; dehydroepiandrosterone sulfate; CYP17; 3 beta-hydroxysteroid dehydrogenase/Delta(5/4)-isomerases; cytochrome b(5)
Categories
Ask authors/readers for more resources
The biosynthesis of dehydroepiandrosterone (DHEA) from cholesterol involves only two enzymes, both cytochrome P450s. The conversion of cholesterol to pregnenolone is mediated by cholesterol side-chain cleavage enzyme (CYP11A1), which is found in the mitochondria. The cleavage of pregnenolone to DHEA requires both the 17alpha-hydroxylase and 17,20-lyase activities of CYP17, which is found in the endoplasmic reticulum. These conversions require pairs of electron transfer proteins or redox partners, which are adrenodoxin and adrenodoxin reductase for CYP11A1 and cytochrome P450-oxidoreductase and cytochrome b(5) for CYP17. In addition, the steroidogenic acute regulatory (StAR) protein regulates the flux of cholesterol into the biosynthetic pathway and represents the mechanism of acute regulation. Finally, in addition to possessing CYP11A1 and CYP17, it is equally important that a steroidogenic cell not contain other enzymes that drain the flux of pregnenolone to DHEA. These characteristics are illustrated by the fetal adrenal cortex and the zona reticularis, which are dedicated to the synthesis of DHEA and DHEA-sulfate.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available