CYP26A1
Description
The CYP26A1 (cytochrome P450 family 26 subfamily A member 1) is a protein-coding gene located on chromosome 10.
CYP26A1 is a protein encoded by the CYP26A1 gene in humans. It belongs to the cytochrome P450 superfamily of enzymes, which are monooxygenases involved in drug metabolism and synthesis of cholesterol, steroids, and other lipids. CYP26A1 is located in the endoplasmic reticulum and acts on retinoids, including all-trans-retinoic acid (RA), with both 4-hydroxylation and 18-hydroxylation activities. This enzyme regulates the cellular level of retinoic acid, which is crucial for gene expression in both embryonic and adult tissues. Two alternatively spliced transcript variants of CYP26A1, encoding distinct isoforms, have been reported. CYP26A1 is overexpressed in colorectal cancer cells compared to normal colonic epithelium, but its prognostic value in colorectal cancer patients is not independent.
CYP26A1 is a cytochrome P450 monooxygenase that plays a crucial role in the metabolism of retinoates (RAs), which are active metabolites of vitamin A and essential signaling molecules in animals. RAs exist in various forms, with all-trans-RA (atRA) being the primary biologically active isomer, although 9-cis-RA and 13-cis-RA also exhibit activity. CYP26A1 primarily catalyzes the hydroxylation of atRA at positions C-4 and C-18, which regulates atRA homeostasis and signaling. This hydroxylation process limits atRA's biological activity and initiates its degradation, leading to eventual elimination. CYP26A1 is also involved in the conversion of atRA to all-trans-4-oxo-RA. Additionally, it can metabolize other RAs, such as 9-cis, 13-cis, and 9,13-di-cis RA. Furthermore, CYP26A1 can oxidize all-trans-13,14-dihydroretinoate (DRA) to various metabolites, including all-trans-4-oxo-DRA, all-trans-4-hydroxy-DRA, all-trans-5,8-epoxy-DRA, and all-trans-18-hydroxy-DRA. CYP26A1 may also participate in the oxidative metabolism of xenobiotics, such as tazarotenic acid.
CYP26A1 is also known as CP26, CYP26, P450RAI, P450RAI1.
