CLONING AND EXPRESSION ANALYSIS OF A CDNA CODING FOR A DEXAMETHASONE-INDUCIBLE CYTOCHROME-P450 IN XENOPUS-LAEVIS LIVER

We previously purified a cytochrome P450 (P450) from liver microsomes of adult female Xenopus laevis. In this study, we screened a cDNA libr ary of Xenopus liver to isolate the cDNA clone coding for this P450. T he 5'-end of the resultant cDNA was truncated at the N-terminal region and extended by method of rapid amplification of cDNA end to give the complete coding sequence. Amino acid sequence showed this clone to be 36% to 55% identical to members of the CYP2 family and less than 31% identical to members of other gene families, and to belong to the CYP2 Q subfamily. This gene is expressed constitutively in the livers of ad ult male and female frogs, and is significantly induced by dexamethaso ne administration.