Functional Expression of the HumanMDR1Gene inEscherichia coli

In this preliminary study, we report the cloning of the humanMDR1cDNA into a prokaryotic expression vector and the consequent functional expression of heterologous P-glycoprotein inEscherichia coli.We demonstrate increased resistance to the P-glycoprotein substrates TPA+, TPP+, and puromycin; reduced accumulation of TPP+and tetracycline by resistant cells; and the expression of a full-length immunoreactive P-glycoprotein molecule in the membrane fraction of resistant cells. The obvious structural and functional similarities of P-gp to prokaryotic ABC transporters and other efflux transporters argues for a more complete study of the consequences pertaining to the expression of human P-glycoprotein inE. coli.