The hybrid rat cytochrome P450 containing the first 5 exons of the CYP11B1 and last 4 exons from the CYP11B2 enzyme retains 11 beta-hydroxylase activity, but the alternative hybrid is inactive.
Human, mouse and rats have 2 different cytochrome P-450 11 beta-hydroxylases in the adrenal cortex. The classical rat 11 beta-hydroxylase or CYP11B1 enzyme hydroxylates deoxycorticosterone to corticosterone and 18-hydroxydeoxycorticosterone and is located throughout the adrenal. The second aldosterone synthase or CYP11B2 enzyme is located in the zona glomerulosa and converts deoxycorticosterone to corticosterone, 18-hydroxycorticosterone and aldosterone. In rat the coding nucleotide sequence and the deduced amino acid sequences of the CYP11B1 and CYP11B2 genes are homologous by 88% and 83%, respectively. We have constructed two different hybrid cDNAs by exchanging two fragments of the rat CYP11B1 and CYP11B2 at the junction of the 5/6 exon and expressed them in COS 7 cells. The hybrid CYPH11B1 construct containing the first 5 exons of the CYP11B1 when expressed, retains 11 beta-hydroxylase activity, but cannot process corticosterone to 18-hydroxycorticosterone or aldosterone. The hybrid CYPH11B2 construct containing the first 5 exons of the CYP11B2 enzyme when expressed is inactive.
Zhou
M Y
MY
Department of Internal Medicine, University of Missouri-Columbia School of Medicine.
Gomez-Sanchez
C E
CE
Xue
D
D
Foecking
M F
MF
D000818:Animals; D001483:Base Sequence; D019405:Cytochrome P-450 CYP11B2; D003577:Cytochrome P-450 Enzyme System / Q000737:chemistry*; D008969:Molecular Sequence Data; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D013252:Steroid 11-beta-Hydroxylase / Q000737:chemistry*; D013329:Structure-Activity Relationship; D013379:Substrate Specificity
D011993:Recombinant Fusion Proteins; D003577:Cytochrome P-450 Enzyme System; D019405:Cytochrome P-450 CYP11B2; D013252:Steroid 11-beta-Hydroxylase