Cytochrome P450, family 2, subfamily A, polypeptide 7 (CYP2A7)

Cytochrome P450, family 2, subfamily A, polypeptide 7 (CYP2A7) is a member of the cytochrome P450 superfamily of monooxygenase enzymes localized to the endoplasmic reticulum[4][3]. While closely related to CYP2A6, which is important for nicotine and coumarin metabolism, CYP2A7 itself has little direct catalytic activity in vitro and does not metabolize classic CYP2A6 substrates such as nicotine or coumarin[1]. It is capable of hydroxylating certain probes such as proluciferin derivatives and diclofenac, but its full range of substrates is unknown[1]. CYP2A7 is highly polymorphic, with common allelic variations causing amino acid changes in the majority of the population[1]. Alongside potential minimal enzymatic roles, evidence suggests that CYP2A7 plays an indirect regulatory function by providing regulatory sequences in gene conversion events with CYP2A6 and by acting as a molecular decoy for microRNAs, thereby potentially influencing the expression and activity of CYP2A6 (and, indirectly, nicotine metabolism and tobacco-related cancer risk)[3]. Upregulation of CYP2A7 expression has been seen in malignant esophageal and colon cancer cells, hinting at associations with cancer, though the mechanistic link remains unclear[6]. Known inhibitors of CYP2A7 include ketoconazole and letrozole[1]. Overall, CYP2A7's enzymatic function in vivo is poorly characterized, with its primary significance possibly arising from its genetic and regulatory interactions with other cytochrome P450 genes rather than from direct drug metabolism.

Other names

Cytochrome P450 2A7CYP2ACYPIIA7Cytochrome P450 IIA4CPA7CPADP450-IIA4cytochrome P450IIA4

Inhibition by azole antifungals and aromatase inhibitors (e.g., ketoconazole, letrozole); Hydroxylation (limited substrate specificity; acts as monooxygenase on select substrates); Polymorphism may alter enzymatic properties and drug interactions