Identification of distinct P-glycoprotein gene sequences in rat.

In higher vertebrates, P-glycoprotein is usually encoded by a small family of genes. We have determined that the rat contains three P-glycoprotein genes and have cloned distinct genomic fragments containing the putative 3' untranslated regions of these P-glycoprotein genes. Sequence analysis indicates that the rat P-glycoprotein genes belong to the three P-glycoprotein classes identified in mammals. These cloned sequences will be useful for delineating the expression of P-glycoprotein genes in the rat. We have also isolated a fourth clone which contains only a short, but highly conserved P-glycoprotein domain. This clone appears not be a member of the P-glycoprotein gene family, and its relationship to P-glycoprotein is unknown.