title: Generation and characterization of a CYP2A13/2B6/2F1-transgenic mouse model.
abstract: CYP2A13, CYP2B6, and CYP2F1, which are encoded by neighboring cytochrome P450 genes on human chromosome 19, are active in the metabolic activation of many drugs, respiratory toxicants, and chemical carcinogens. To facilitate studies on the regulation and function of these human genes, we have generated a CYP2A13/2B6/2F1-transgenic (TG) mouse model (all *1 alleles). Homozygous transgenic mice are normal with respect to gross morphological features, development, and fertility. The tissue distribution of transgenic mRNA expression agreed well with the known respiratory tract-selective expression of CYP2A13 and CYP2F1 and hepatic expression of CYP2B6 in humans. CYP2A13 protein was detected through immunoblot analyses in the nasal mucosa (NM) (∼100 pmol/mg of microsomal protein; similar to the level of mouse CYP2A5) and the lung (∼0.2 pmol/mg of microsomal protein) but not in the liver of the TG mice. CYP2F1 protein, which could not be separated from mouse CYP2F2 in immunoblot analyses, was readily detected in the NM and lung but not the liver of TG/Cyp2f2-null mice, at levels 10- and 40-fold, respectively, lower than that of mouse CYP2F2 in the TG mice. CYP2B6 protein was detected in the liver (∼0.2 pmol/mg of microsomal protein) but not the NM or lung (with a detection limit of 0.04 pmol/mg of microsomal protein) of the TG mice. At least one transgenic protein (CYP2A13) seems to be active, because the NM of the TG mice had greater in vitro and in vivo activities in bioactivation of a CYP2A13 substrate, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (a lung carcinogen), than did the NM of wild-type mice.
authors.affiliation: Wadsworth Center, New York State Department of Health, Empire State Plaza, Box 509, Albany, NY 12201-0509, USA.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Wei
authors.forename: Hong
authors.initials: H
authors.lastname: Wu
authors.forename: Lei
authors.initials: L
authors.lastname: Li
authors.forename: Zhihua
authors.initials: Z
authors.lastname: Liu
authors.forename: Xin
authors.initials: X
authors.lastname: Zhou
authors.forename: Qing-Yu
authors.initials: QY
authors.lastname: Zhang
authors.forename: Yan
authors.initials: Y
authors.lastname: Weng
authors.forename: Jaime
authors.initials: J
authors.lastname: D'Agostino
authors.forename: Guoyu
authors.initials: G
authors.lastname: Ling
authors.forename: Xiuling
authors.initials: X
authors.lastname: Zhang
authors.forename: Kerri
authors.initials: K
authors.lastname: Kluetzman
authors.forename: Yunyi
authors.initials: Y
authors.lastname: Yao
authors.forename: Xinxin
authors.initials: X
authors.lastname: Ding
mesh_terms: D000293:Adolescent; D000818:Animals; D001189:Aryl Hydrocarbon Hydroxylases / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics; D065702:Cytochrome P-450 CYP2B6; D003577:Cytochrome P-450 Enzyme System / Q000096:biosynthesis* / Q000172:deficiency / Q000235:genetics; D000072467:Cytochrome P450 Family 2; D005260:Female; D006801:Humans; D008099:Liver / Q000201:enzymology; D008168:Lung / Q000201:enzymology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008822:Mice, Transgenic; D023421:Models, Animal; D005810:Multigene Family / Q000235:genetics*; D009297:Nasal Mucosa / Q000201:enzymology; D010089:Oxidoreductases, N-Demethylating / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics; D014018:Tissue Distribution / Q000235:genetics
chemical_list: D003577:Cytochrome P-450 Enzyme System; D001189:Aryl Hydrocarbon Hydroxylases; C414206:CYP2A13 protein, human; C585599:CYP2B6 protein, human; C110332:CYP2F1 protein, human; D065702:Cytochrome P-450 CYP2B6; D000072467:Cytochrome P450 Family 2; D010089:Oxidoreductases, N-Demethylating