title: Identification of mitochondrial cytochrome P450 induced in response to polycyclic aromatic hydrocarbons in the mummichog (Fundulus heteroclitus).
abstract: Increasing evidence suggests that polycyclic aromatic hydrocarbons (PAHs) such as benzo[a]pyrene (BaP) are localized to the mitochondria. Because the toxic effects of many PAHs are the result of metabolism by cytochrome P4501A (CYP1A), it is important to investigate whether active forms of these enzymes can be identified in the mitochondria. In this study, we identified mitochondrial P450s with a monoclonal antibody against scup (Stenotomus chrysops) CYP1A in the isolated mitochondrial fraction of the liver from adult male mummichog (Fundulus heteroclitus) livers. The size of the protein in the mitochondria was similar to that of microsomal CYP1A. Fish dosed with 10mg/kg BaP had increased EROD activity in the mitochondrial fraction compared to controls. In mummichog larvae dosed with 100 microg/L BaP and 100 microg/L benzo[k]fluoranthene, CYP1A protein levels as well as enzyme activity were elevated. However, fish from a PAH-polluted Superfund site (Elizabeth River, Portsmouth VA) showed recalcitrant mitochondrial CYP1A protein levels and enzyme activity in a similar manner to microsomal CYP1A.
authors.affiliation: Nicholas School of the Environment, Duke University, Durham, NC 27708, USA.
authors.forename: Dawoon
authors.initials: D
authors.lastname: Jung
authors.forename: Richard T
authors.initials: RT
authors.lastname: Di Giulio
mesh_terms: D000818:Animals; D001564:Benzo(a)pyrene / Q000633:toxicity*; D019363:Cytochrome P-450 CYP1A1 / Q000378:metabolism*; D029941:Fish Proteins / Q000378:metabolism*; D005449:Fluorenes / Q000633:toxicity*; D023781:Fundulidae / Q000196:embryology / Q000378:metabolism*; D007814:Larva / Q000187:drug effects / Q000201:enzymology; D008297:Male; D008862:Microsomes, Liver / Q000187:drug effects / Q000201:enzymology; D008930:Mitochondria, Liver / Q000187:drug effects* / Q000201:enzymology; D010078:Oxazines / Q000378:metabolism; D010766:Phosphorylation; D011499:Protein Processing, Post-Translational; D018336:Receptors, Aryl Hydrocarbon / Q000819:agonists; D013379:Substrate Specificity; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D029941:Fish Proteins; D005449:Fluorenes; D010078:Oxazines; D018336:Receptors, Aryl Hydrocarbon; D014874:Water Pollutants, Chemical; D001564:Benzo(a)pyrene; C007649:ethoxyresorufin; D019363:Cytochrome P-450 CYP1A1; C022921:benzo(k)fluoranthene