Cytochrome P450 family 1 subfamily A member 1 (CYP1A1)

Cytochrome P450 family 1 subfamily A member 1 (CYP1A1), historically known as Aryl hydrocarbon hydroxylase (AHH), is a vital microsomal enzyme involved in the Phase I metabolism of xenobiotics and endogenous compounds (UniProt: P04798). While it is primarily expressed in extrahepatic tissues such as the lungs and skin, its expression is highly inducible by environmental pollutants, such as polycyclic aromatic hydrocarbons (PAHs) and dioxins, via the Aryl Hydrocarbon Receptor (AhR) signaling pathway (NCBI Gene ID: 1543). CYP1A1 plays a complex role in human health; although it facilitates the clearance of certain toxins, it is also responsible for the metabolic activation of procarcinogens into highly reactive epoxides that form DNA adducts, significantly increasing the risk of various cancers (PubMed: 25619962). In pharmacological contexts, CYP1A1 is a target for chemopreventive agents that aim to inhibit its activity to prevent carcinogen activation, and it serves as a critical biomarker for environmental exposure and AhR activation (PubChem CID: 11843209). Understanding CYP1A1's activity is essential for assessing drug toxicity and individual susceptibility to chemically induced diseases.

Other names

Aryl hydrocarbon hydroxylaseAHHP450DXCP11Cytochrome P450-CCytochrome P450-P1Benzo[a]pyrene hydroxylase

Substrate oxidation and hydroxylation through a heme-mediated catalytic cycle, often following induction by the Aryl Hydrocarbon Receptor (AhR). Drugs may act as competitive inhibitors to prevent procarcinogen activation or as ligands for AhR to induce enzyme expression.