Steroidogenic enzyme

Steroidogenic enzymes are enzymes that are involved in steroidogenesis and steroid biosynthesis.^[2][3][4][5] They are responsible for the biosynthesis of the steroid hormones, including sex steroids (androgens, estrogens, and progestogens) and corticosteroids (glucocorticoids and mineralocorticoids), as well as neurosteroids, from cholesterol.^[3][4][5] Steroidogenic enzymes are most highly expressed in classical steroidogenic tissues, such as the testis, ovary, and adrenal cortex, but are also present in other tissues in the body.^[3][4][5]

Steroidogenesis of steroid hormones.^[1]

List of steroidogenic enzymes

• Steroid desmolases
  • Cholesterol side-chain cleavage enzyme (20,22-desmolase) – steroid synthesis
  • 17,20-Lyase (17,20-desmolase) – androgen synthesis
• Steroid hydroxylases
  • 11β-Hydroxylase – corticosteroid synthesis
  • 17α-Hydroxylase – androgen and glucocorticoid synthesis
  • 18-Hydroxylase (aldosterone synthase) – mineralocorticoid synthesis
  • 21-Hydroxylase – corticosteroid synthesis
  • Cytochrome P450 (CYP1, 2, 3) – estrogen metabolism
• Hydroxysteroid dehydrogenases (and ketosteroid reductases)
  • 3α-Hydroxysteroid dehydrogenase – androgen, progestogen, and neurosteroid synthesis and metabolism
  • 3β-Hydroxysteroid dehydrogenase/Δ^5-4-isomerase (1, 2) – androgen, progestogen, and neurosteroid synthesis
  • 11β-Hydroxysteroid dehydrogenase (1, 2) – corticosteroid synthesis and metabolism
  • 17β-Hydroxysteroid dehydrogenase (1–15) – androgen, estrogen, and progestogen synthesis and metabolism
  • 20α-Hydroxysteroid dehydrogenase – progestogen synthesis and metabolism
  • 20β-Hydroxysteroid dehydrogenase – progestogen synthesis and metabolism

Steroid numbering.

• Steroid reductases
  • 5α-Reductase (1, 2, 3) – androgen and neurosteroid synthesis, progestogen metabolism
  • 5β-Reductase – androgen and progestogen metabolism, neurosteroid synthesis
• Conjugation (and deconjugation)
  • Glucuronosyltransferase (UGT2Bs) – steroid metabolism^[6]
  • Glucuronidase (β-glucuronidase) – steroid synthesis^[7]
  • Steroid sulfotransferase (SULT1A1, 1E1, 2A1, 2B1a, 2B1b) – steroid metabolism, neurosteroid synthesis^[8]
  • Steroid sulfatase – steroid synthesis, neurosteroid metabolism^[8]
• Others
  • Aromatase (estrogen synthetase) – estrogen synthesis

See also

• Inborn errors of steroid metabolism
• Steroidogenesis inhibitor