Characterization of the humanMDR1 gene

Abstract
P-glycoprotein (Pgp), an ATP-dependent efflux transporter that protects the body from environmental toxins and xenobiotics, is encoded by the humanMDR1 gene. HumanMDR1 is located on chromosomal region 7q21. Although several different single nucleotide polymorphisms were shown to influence Pgp expression and activity, the reported length of theMDR1 gene in Genbank and other databases continues to evolve and varies between 6.3 kilobases (kb) and 210 kb. With DNA derived from human cell lines and tissues, we have characterized theMDR1 genomic sequence to be 209 kb.