Cytochrome P450 2E polymorphism in feline liver.
Only one isoform of cytochrome P450 (CYP) 2E subfamily was known in human and various animals. Three cDNAs corresponding to CYP 2E subfamily members (CYP2E-a, CYP2E-b and CYP2E-c) were obtained from feline liver. These cDNAs each had a 1488-bp nucleotide coding region encoding a predicted amino acid sequence of 495 residues. Eleven amino acid substitutions were observed between CYP2E-a and CYP2E-b, but only one substitution between CYP2E-b and CYP2E-c. The CO difference spectrums about 450 nm wave length and similar values of Vmax and Km of 6-hydoxygenase activity toward chlorzoxazone were observed in all three isoforms expressed in AH22 yeast cells. By PCR-RFLP, mRNA of the CYP2E-a was found to be expressed in liver, mononuclear cells, kidney, lung, stomach, intestine and pancreas, whereas CYP2E-b and CYP2E-c were expressed mainly in the liver and mononuclear cells. Expression of CYP2E-a was observed in the livers of all felines tested, but CYP2E-b and CYP2E-c were not expressed in all cats. The sequences of two different introns between exons I and II and between exons VII and VIII were obtained in genomic DNA from the feline liver. Based on these results, we conclude that cats have two highly similar CYP2E genes.
Tanaka
Nagako
N
Laboratory of Veterinary Biochemistry, Graduate School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Hokkaido 069-8501, Japan.
Shinkyo
Raku
R
Sakaki
Toshiyuki
T
Kasamastu
Masahiko
M
Imaoka
Susumu
S
Funae
Yoshihiko
Y
Yokota
Hiroshi
H
D000595:Amino Acid Sequence; D000818:Animals; D002415:Cats; D002753:Chlorzoxazone / Q000737:chemistry; D003001:Cloning, Molecular / Q000379:methods; D003577:Cytochrome P-450 Enzyme System / Q000737:chemistry / Q000235:genetics*; D018076:DNA, Complementary / Q000235:genetics; D005091:Exons / Q000235:genetics; D007527:Isoenzymes / Q000737:chemistry / Q000235:genetics; D007668:Kidney / Q000201:enzymology; D007963:Leukocytes, Mononuclear / Q000201:enzymology; D008099:Liver / Q000201:enzymology*; D008969:Molecular Sequence Data; D009928:Organ Specificity / Q000502:physiology; D010802:Phylogeny; D012150:Polymorphism, Restriction Fragment Length; D013379:Substrate Specificity / Q000502:physiology
D018076:DNA, Complementary; D007527:Isoenzymes; D003577:Cytochrome P-450 Enzyme System; D002753:Chlorzoxazone