EC Number   |
Natural Substrates |
|---|
    1.1.1.270 | (3)H-dehydroepiandrosterone + NAD(P)+ |
- |
| 1.1.1.270 | (4-methyl)zymosterone + NADPH + H+ |
cholesterol pathway |
| 1.1.1.270 | 2 17beta-hydroxy-5alpha-androstan-3-one + 2 NADPH + 2 H+ |
AKR1cs are a source of beta-tetrahydrosteroids. This is of physiological significance because the formation of 3beta-diol in contrast to 3alpha-diol is virtually irreversible, the 3beta-diol is a pro-apoptotic ligand for estrogen receptor beta, and 3beta-tetrahydrosteroids act as gamma-aminobutyric acid type A receptor antagonists |
| 1.1.1.270 | 5alpha-dihydrotestosterone + NADPH + H+ |
in prostate cells AKR1C2 acts as a 3-ketosteroid reductase to eliminate 5alpha-dihydrotestosterone and prevents activation of androgen receptor. AKR1C2 does not act as an oxidase due to either potent product inhibition by NADPH or because it cannot surmount the oxidative 17beta-hydroxysteroid dehydrogenase present. AKR1C2 is not a source of 5alpha-dihydrotestosterone in PC-3 cells |
| 1.1.1.270 | androstenedione + NAD(P)H |
- |
| 1.1.1.270 | dihydrotestosterone + NADPH + H+ |
steroid hormone pathway |
| 1.1.1.270 | more |
catalyzes the conversion of 3-keto-saturated steroids such as 5alpha-dihydrotestosterone, DHT, and 5alpha-androstane-3,17-dione, A-dione, into less active steroids |
| 1.1.1.270 | more |
catalyzes NADPH-dependent reduction of 3-ketosteroid intermediates, 4-methyl sterol intermediates, of cholesterol biosynthesis from lanosterol, regenerates 3beta-hydroxy sterol |
| 1.1.1.270 | more |
enzyme of cholesterol biosynthesis |
| 1.1.1.270 | more |
enzyme of sterol, ergosterol, biosynthesis, enzyme catalyzes last step in demethylation at C-4 |
