Detection of aromatase cytochrome P450, 17 alpha-hydroxylase cytochrome P450 and NADPH:P450 reductase on the surface of cells in which they are expressed.
Using the membrane impermeant probe NHS-LC-biotin, we show in this report that a fraction of aromatase P450 (P450arom), the enzyme that catalyzes estrogen biosynthesis, is present at the surface of cells in which it is expressed, either endogenously or as a consequence of transfection. The same findings were obtained for a truncated form of P450arom lacking the putative membrane-spanning region, thus suggesting the presence of other membrane-spanning region(s) within its structure. P450arom is not unique in this regard as we find that a fraction of 17 alpha-hydroxylase P450 as well as NADPH:P450 reductase also are present at the cell surface. It is therefore possible that a number of microsomal P450s are expressed at the cell surface in this fashion.
Amarneh
B A
BA
Cecil H. and Ida Green Center for Reproductive Biology Sciences, University of Texas Southwestern Medical Center, Dallas 75235-9051, USA.
Simpson
E R
ER
D000818:Animals; D001141:Aromatase / Q000378:metabolism*; D002460:Cell Line; D002461:Cell Line, Transformed; D002462:Cell Membrane / Q000378:metabolism; D002522:Chlorocebus aethiops; D006801:Humans; D008565:Membrane Proteins / Q000378:metabolism*; D009247:NADH, NADPH Oxidoreductases / Q000378:metabolism*; D009251:NADPH-Ferrihemoprotein Reductase; D013254:Steroid 17-alpha-Hydroxylase / Q000378:metabolism*; D014162:Transfection; D014407:Tumor Cells, Cultured
D008565:Membrane Proteins; D001141:Aromatase; D013254:Steroid 17-alpha-Hydroxylase; D009247:NADH, NADPH Oxidoreductases; D009251:NADPH-Ferrihemoprotein Reductase