CYP11B1
Function
A cytochrome P450 monooxygenase involved in the biosynthesis of adrenal corticoids (PubMed:12530636, PubMed:1518866, PubMed:1775135, PubMed:18215163, PubMed:23322723). Catalyzes a variety of reactions that are essential for many species, including detoxification, defense, and the formation of endogenous chemicals like steroid hormones. Steroid 11beta, 18- and 19-hydroxylase with preferred regioselectivity at 11beta, then 18, and lastly 19 (By similarity). Catalyzes the hydroxylation of 11-deoxycortisol and 11-deoxycorticosterone (21-hydroxyprogesterone) at 11beta position, yielding cortisol or corticosterone, respectively, but cannot produce aldosterone (PubMed:12530636, PubMed:1518866, PubMed:1775135, PubMed:18215163, PubMed:23322723). Mechanistically, uses molecular oxygen inserting one oxygen atom into a substrate for hydroxylation and reducing the second into a water molecule. Two electrons are provided by NADPH via a two-protein mitochondrial transfer system comprising flavoprotein FDXR (adrenodoxin/ferredoxin reductase) and nonheme iron-sulfur protein FDX1 or FDX2 (adrenodoxin/ferredoxin) (PubMed:18215163). Due to its lack of 18-oxidation activity, it is incapable of generating aldosterone (PubMed:23322723). Could also be involved in the androgen metabolic pathway (Probable).
Involvement in disease
Adrenal hyperplasia 4
AH4
A form of congenital adrenal hyperplasia, a common recessive disease due to defective synthesis of cortisol. Congenital adrenal hyperplasia is characterized by androgen excess leading to ambiguous genitalia in affected females, rapid somatic growth during childhood in both sexes with premature closure of the epiphyses and short adult stature. Four clinical types: 'salt wasting' (SW, the most severe type), 'simple virilizing' (SV, less severely affected patients), with normal aldosterone biosynthesis, 'non-classic form' or late-onset (NC or LOAH) and 'cryptic' (asymptomatic).
None
The disease is caused by variants affecting the gene represented in this entry.
Hyperaldosteronism, familial, 1
HALD1
A disorder characterized by hypertension, variable hyperaldosteronism, and abnormal adrenal steroid production, including 18-oxocortisol and 18-hydroxycortisol. There is significant phenotypic heterogeneity, and some individuals never develop hypertension.
None
The disease is caused by variants affecting the gene represented in this entry. The molecular defect causing hyperaldosteronism familial 1 is an anti-Lepore-type fusion of the CYP11B1 and CYP11B2 genes. The hybrid gene has the promoting part of CYP11B1, ACTH-sensitive, and the coding part of CYP11B2.
Pathway
Steroid biosynthesis; glucocorticoid biosynthesis.
Steroid hormone biosynthesis.
Sequence Similarities
Belongs to the cytochrome P450 family.
Tissue Specificity
Expressed in the zona fasciculata/reticularis of the adrenal cortex.
Cellular localization
- Mitochondrion inner membrane
- Peripheral membrane protein
Alternative names
S11BH, CYP11B1, CYPXIB1, Cytochrome P-450c11, Cytochrome P450C11