Two forms of omega-hydroxylase toward prostaglandin A and laurate. cDNA cloning and their expression.
We have isolated cDNA clones for two forms of P-450s, P-450ka-1 and P-450ka-2, from a rabbit kidney cDNA library, using the cDNA for rabbit pulmonary cytochrome P-450p-2, a prostaglandin omega-hydroxylase (Matsubara, S., Yamamoto, S., Sogawa, K., Yokotani, N., Fujii-Kuriyama, Y., Haniu, M., Shively, J.E., Gotoh, O., Kusunose, E., and Kusunose, M. (1987) J. Biol. Chem. 262, 13366-13371), as a hybridization probe. The cDNAs for P-450ka-1 and P-450ka-2 encode polypeptides of 510 and 511 amino acids, respectively, with sequence similarity of 85% and 87% to P-450p-2. The two deduced primary structures have 87% identity. RNA blot analysis demonstrated that the mRNAs for P-450ka-1 and P-450ka-2 formed single bands at approximately 3.0- and 2.6-kilobase positions, respectively. The mRNA for P-450ka-1 was expressed only in the liver and kidney and was increased remarkably in these tissues by the administration of clofibrate. In contrast, the mRNA for P-450ka-2 was expressed constitutively in the liver, kidney, and small intestine, but its transcription was enhanced only in the liver by clofibrate treatment. Thus, in spite of their high sequence similarity, these P-450 species have different modes of regulatory expression. Comparison of the nucleotide sequences among P-450ka-1, P-450ka-2, and P-450p-2 shows about 90% overall sequence similarity in any pair of the three sequences. Nucleotide replacements are not evenly distributed, but are rather biased. There is a region of approximately 500 base pairs of exceptionally high homology among the three sequences. These results indicate that the gene conversion event occurred during the evolutionary process of these genes.
Yokotani
N
N
Department of Chemistry, Faculty of Science, Tohoku University, Aoba Sendai, Japan.
Bernhardt
R
R
Sogawa
K
K
Kusunose
E
E
Gotoh
O
O
Kusunose
M
M
Fujii-Kuriyama
Y
Y
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D002994:Clofibrate / Q000494:pharmacology; D003001:Cloning, Molecular / Q000379:methods*; D042926:Cytochrome P-450 CYP4A; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics* / Q000378:metabolism; D004247:DNA / Q000235:genetics*; D015870:Gene Expression; D015723:Gene Library; D005796:Genes; D007527:Isoenzymes / Q000235:genetics* / Q000378:metabolism; D007668:Kidney / Q000187:drug effects / Q000201:enzymology*; D007850:Lauric Acids / Q000378:metabolism*; D008297:Male; D006899:Mixed Function Oxygenases / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D009928:Organ Specificity; D011454:Prostaglandins A / Q000378:metabolism*; D011817:Rabbits; D015183:Restriction Mapping; D012689:Sequence Homology, Nucleic Acid
D007527:Isoenzymes; D007850:Lauric Acids; D011454:Prostaglandins A; C030358:lauric acid; D004247:DNA; D003577:Cytochrome P-450 Enzyme System; D006899:Mixed Function Oxygenases; D042926:Cytochrome P-450 CYP4A; D002994:Clofibrate