Physiological functions of multidrug transporters in yeast

Overexpression of drug extrusion pumps belonging to the ABC (ATP-binding cassette) super family of proteins is one of the most common mechanisms of multidrug resistance in various organisms. Both pathogenic and non-pathogenic yeast cells also become resistant to a variety of drugs by overexpressing genes encoding ABC drug efflux pumps. Recent evidences reveal that not only the well-characterized human drug extrusion pump (MDR1/P-gp), but its close homologues in yeast also mediate several cellular functions. Keeping in view the importance of ABC drug transporters in yeasts, this review particularly focuses on their physiological roles.