Reduction of androstenedione to testosterone

Stable Identifier
Reaction [transition]
Homo sapiens
Locations in the PathwayBrowser
SVG |   | PPTX  | SBGN
Click the image above or here to open this reaction in the Pathway Browser
The layout of this reaction may differ from that in the pathway view due to the constraints in pathway layout

The 17HSD family of enzymes catalyze the final step in the synthesis of estradiol and testosterone. They convert inactive 17-ketosteroids to their active 17beta-hydroxy forms. Androstenedione, a ketosteroid, is reduced to testosterone, a highly potent androgen, by the enzyme 17beta-hydroxysteroid dehydrogenase isoform III (17HSD3). The other human isoforms of 17HSDs to take part in the final steps of active steroid biosynthesis are types 1 and VII, which reduce estrone to estradiol.
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).
In males, Lutropin (LH) stimulates testosterone production.

Literature References
PubMed ID Title Journal Year
9536209 A critical review of the origin and control of adrenal androgens

McKenna, TJ, Fearon, U, Clarke, D, Cunningham, SK

Baillieres Clin Obstet Gynaecol 1997
8547185 Characteristics of human types 1, 2 and 3 17 beta-hydroxysteroid dehydrogenase activities: oxidation/reduction and inhibition

Luu-The, V, Zhang, Y, Poirier, D, Labrie, F

J Steroid Biochem Mol Biol 1995
2197970 Purification, cloning, complementary DNA structure, and predicted amino acid sequence of human estradiol 17 beta-dehydrogenase

Luu-The, V, Labrie, C, Zhao, HF, Couet, J, Lachance, Y, Simard, J, Cote, J, Leblanc, G, Lagace, L, Berube, D, Gagne, R, Labrie, F

Ann N Y Acad Sci 1990
8075637 Male pseudohermaphroditism caused by mutations of testicular 17 beta-hydroxysteroid dehydrogenase 3

Geissler, WM, Davis, DL, Wu, L, Bradshaw, KD, Patel, S, Mendonca, BB, Elliston, KO, Wilson, JD, Russell, DW, Andersson, S

Nat Genet 1994
Participant Of
Catalyst Activity
Catalyst Activity
testosterone dehydrogenase [NAD(P)] activity of HSD17B3-like Proteins [endoplasmic reticulum membrane]
Physical Entity
This event is regulated
Orthologous Events
Cross References
Cite Us!