Main pageKEGG pathway → Steroid hormone biosynthesis

KEGG pathway: Steroid hormone biosynthesis

Pathway hsa00140
Name Steroid hormone biosynthesis
Members CYP19A1 HSD17B3 UGT2B17 UGT1A5 UGT2B28 COMT HSD17B8 UGT2B7 UGT1A8 UGT2B10 UGT2B4 CYP3A4 UGT2B15 CYP3A5 HSD3B1 HSD17B7 CYP3A43 UGT1A1 CYP11B2 UGT2A3 SRD5A1 UGT1A4 AKR1C4 CYP3A7 UGT2A1 HSD11B2 CYP11B1 CYP17A1 CYP1A1 AKR1D1 HSD17B1 UGT1A3 CYP7A1 SULT1E1 SULT2B1 UGT2B11 UGT1A7 HSD17B2 HSD3B2 HSD17B12 UGT1A10 UGT1A9 SRD5A3 CYP11A1 UGT1A6 AKR1C3 AKR1C1 CYP1B1 AKR1C1 HSD11B1 STS HSD17B6 CYP7B1 AKR1C2
Description Steroid hormones derived from cholesterol are a class of biologically active compounds in vertebrates. The cholesterol side-chain cleavage enzyme CYP11A1 catalyzes conversion of cholesterol, a C27 compound, to the first C21 steroid, pregnenolone, which is converted by a bifunctional enzyme complex to the gestagen hormone, progesterone [MD:M00107]. Pregnenolone and progesterone are the starting materials for the three groups of steroids: C21 steroids of glucocorticoids and mineralocorticoids, C19 steroids of androgens, and C18 steroids of estrogens. (i) Progesterone is converted by hydroxylations at carbons 21 and 11 to corticosterone, which is further modified by hydroxylation and oxydoreduction at carbon 18 to yield aldosterone, a mineralcorticoid [MD:M00108]. Cortisol, the main glucocorticoid, is formed from 17alpha-hydroxyprogesterone with 11-deoxycortisol as an intermediate [MD:M00109]. (ii) Male hormone testosterone is formed from pregnenolone by two pathways, delta5 pathway via dehydroepiandrosterone and delta4 pathway via androstenedione [MD:M00110]. The enzyme CYP17A1 is responsible for the 17,20 lyase and 17alpha-hydroxylase activities in respective pathways. (iii) Female hormones estrone and estradiol are formed from testosterone and 4-androstene-3,17-dione by oxidative removal of the C19 methyl group and subsequent aromatization of ring A [MD:M00111]. In addition to these three groups, recent studies show that there is another group, termed neurosteroids, synthesized in the brain rather than the peripheral endocrine gland.