A cytochrome P450 monooxygenase involved in the metabolism of various endogenous substrates, including fatty acids, steroid hormones and vitamins (PubMed:20972997, PubMed:11555828, PubMed:12865317, PubMed:10681376, PubMed:15258110). Mechanistically, uses molecular oxygen inserting one oxygen atom into a substrate, and reducing the second into a water molecule, with two electrons provided by NADPH via cytochrome P450 reductase (NADPH--hemoprotein reductase) (PubMed:20972997, PubMed:11555828, PubMed:12865317, PubMed:10681376, PubMed:15258110). Exhibits catalytic activity for the formation of hydroxyestrogens from estrone (E1) and 17beta-estradiol (E2), namely 2- and 4-hydroxy E1 and E2. Displays a predominant hydroxylase activity toward E2 at the C-4 position (PubMed:11555828, PubMed:12865317). Metabolizes testosterone and progesterone to B or D ring hydroxylated metabolites (PubMed:10426814). May act as a major enzyme for all-trans retinoic acid biosynthesis in extrahepatic tissues. Catalyzes two successive oxidative transformation of all-trans retinol to all-trans retinal and then to the active form all-trans retinoic acid (PubMed:10681376, PubMed:15258110). Catalyzes the epoxidation of double bonds of certain PUFA. Converts arachidonic acid toward epoxyeicosatrienoic acid (EpETrE) regioisomers, 8,9-, 11,12-, and 14,15- EpETrE, that function as lipid mediators in the vascular system (PubMed:20972997). Additionally, displays dehydratase activity toward oxygenated eicosanoids hydroperoxyeicosatetraenoates (HpETEs). This activity is independent of cytochrome P450 reductase, NADPH, and O2 (PubMed:21068195). Also involved in the oxidative metabolism of xenobiotics, particularly converting polycyclic aromatic hydrocarbons and heterocyclic aryl amines procarcinogens to DNA-damaging products (PubMed:10426814). Plays an important role in retinal vascular development. Under hyperoxic O2 conditions, promotes retinal angiogenesis and capillary morphogenesis, likely by metabolizing the oxygenated products generated during the oxidative stress. Also, contributes to oxidative homeostasis and ultrastructural organization and function of trabecular meshwork tissue through modulation of POSTN expression (By similarity). an organic molecule + O2 + reduced [NADPH--hemoprotein reductase] = an alcohol + H(+) + H2O + oxidized [NADPH--hemoprotein reductase] 17beta-estradiol + O2 + reduced [NADPH--hemoprotein reductase] = 2-hydroxy-17beta-estradiol + H(+) + H2O + oxidized [NADPH--hemoprotein reductase] 17beta-estradiol + O2 + reduced [NADPH--hemoprotein reductase] = 4-hydroxy-17beta-estradiol + H(+) + H2O + oxidized [NADPH--hemoprotein reductase] estrone + O2 + reduced [NADPH--hemoprotein reductase] = 2-hydroxyestrone + H(+) + H2O + oxidized [NADPH--hemoprotein reductase] estrone + O2 + reduced [NADPH--hemoprotein reductase] = 4-hydroxyestrone + H(+) + H2O + oxidized [NADPH--hemoprotein reductase] O2 + reduced [NADPH--hemoprotein reductase] + testosterone = 6beta,17beta-dihydroxyandrost-4-en-3-one + H(+) + H2O + oxidized [NADPH--hemoprotein reductase] O2 + progesterone + reduced [NADPH--hemoprotein reductase] = 6beta-hydroxyprogesterone + H(+) + H2O + oxidized [NADPH--hemoprotein reductase] O2 + progesterone + reduced [NADPH--hemoprotein reductase] = 16alpha-hydroxyprogesterone + H(+) + H2O + oxidized [NADPH--hemoprotein reductase] all-trans-retinol + O2 + reduced [NADPH--hemoprotein reductase] = all-trans-retinal + H(+) + 2 H2O + oxidized [NADPH--hemoprotein reductase] all-trans-retinal + O2 + reduced [NADPH--hemoprotein reductase] = all-trans-retinoate + 2 H(+) + H2O + oxidized [NADPH--hemoprotein reductase] (5Z,8Z,11Z,14Z)-eicosatetraenoate + O2 + reduced [NADPH--hemoprotein reductase] = (8R,9S)-epoxy-(5Z,11Z,14Z)-eicosatrienoate + H(+) + H2O + oxidized [NADPH--hemoprotein reductase] (5Z,8Z,11Z,14Z)-eicosatetraenoate + O2 + reduced [NADPH--hemoprotein reductase] = (11R,12S)-epoxy-(5Z,8Z,14Z)-eicosatrienoate + H(+) + H2O + oxidized [NADPH--hemoprotein reductase] (5Z,8Z,11Z,14Z)-eicosatetraenoate + O2 + reduced [NADPH--hemoprotein reductase] = (11S,12R)-epoxy-(5Z,8Z,14Z)-eicosatrienoate + H(+) + H2O + oxidized [NADPH--hemoprotein reductase] (5Z,8Z,11Z,14Z)-eicosatetraenoate + O2 + reduced [NADPH--hemoprotein reductase] = (14R,15S)-epoxy-(5Z,8Z,11Z)-eicosatrienoate + H(+) + H2O + oxidized [NADPH--hemoprotein reductase] (5S)-hydroperoxy-(6E,8Z,11Z,14Z)-eicosatetraenoate = 5-oxo-(6E,8Z,11Z,14Z)-eicosatetraenoate + H2O (12S)-hydroperoxy-(5Z,8Z,10E,14Z)-eicosatetraenoate = 12-oxo-(5Z,8Z,10E,14Z)-eicosatetraenoate + H2O (13S)-hydroperoxy-(9Z,11E)-octadecadienoate = 13-oxo-(9Z,11E)-octadecadienoate + H2O (15S)-hydroperoxy-(5Z,8Z,11Z,13E)-eicosatetraenoate = 15-oxo-(5Z,8Z,11Z,13E)-eicosatetraenoate + H2O Enzyme activity is increased by liposomes containing anionic phospholipids, phosphatidic acid and cardiolipin. Inhibited by naringenin with an IC(50) of 5 uM (PubMed:22888116, PubMed:22935222). Enzyme activity is increased by cytochrome b5. kcat is 0.15 min(-1) for retinol, 0.77 min(-1) for retinal, 2.86 min(-1) for 7,12-dimethyltetraphene, 0.48 min(-1) for arachidonic acid. Steroid hormone biosynthesis. Cofactor metabolism; retinol metabolism. Lipid metabolism; arachidonate metabolism. Located primarily in endoplasmic reticulum. Upon treatment with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), CYP1B1 is also targeted to mitochondria. Expressed in heart, brain, lung, skeletal muscle, kidney, spleen, thymus, prostate, testis, ovary, small intestine, colon, and peripheral blood leukocytes (PubMed:8175734). Expressed in retinal endothelial cells and umbilical vein endothelial cells (at protein level) (PubMed:19005183). By polycyclic aromatic hydrocarbons (PAH) and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Various CYP1B1 alleles are known. The sequence shown is that of allele CYP1B1*1. The disease is caused by variants affecting the gene represented in this entry. The disease is caused by variants affecting distinct genetic loci, including the gene represented in this entry. The gene represented in this entry acts as a disease modifier. Digenic mutations in CYP1B1 and MYOC have been found in a family segregating both primary adult-onset and juvenile forms of open angle glaucoma (PubMed:11774072). All affected family members with mutations in both MYOC and CYP1B1 had juvenile glaucoma, whereas those with only the MYOC mutation had the adult-onset form (PubMed:11774072). Belongs to the cytochrome P450 family. CYP1B1 alleles