Structure and Function of Multidrug Resistance Protein 1.

This review considers one of the most clinically relevant representatives of the ABC transporters - multidrug resistance protein 1 (P-glycoprotein 1 or Pgp). Data on the primary, secondary, and tertiary structure of the protein, its synthesis and degradation, and roles of its fragments in transporter activity are presented. Particular attention is given to the mechanism of functioning of Pgp. In view of the absence of a generally recognized mechanism of action of Pgp, several existing models of the protein transport cycle are discussed. Epigenetic regulation of the ABCB1 gene and modulation of Pgp expression by microRNAs are discussed.