Mutational analysis of the yeast multidrug resistance ABC transporter Pdr5p with altered drug specificity.
Multidrug resistance ABC transporter Pdr5p of Saccharomyces cerevisiae is particularly important due to its ability to export a wide range of unrelated substrates. To clarify its function, we generated Pdr5p mutants by random mutagenesis and screened for mutants with altered drug specificity in vivo by using 5 drug compounds. Nine point mutations that caused significant changes in drug specificity distributed throughout the length of Pdr5p, namely, in the extracellular, transmembrane or cytoplasmic regions of the transporter. We then investigated their effects upon drug resistance, using 36 chemically related or distinct substrates. From this study, overall geometry of the Pdr5p was suggested to contribute in acquiring the enormous range of drug specificity. Based on their ability to inhibit the growth of the mutant strains, the 36 tested drugs were classified into: drugs to which the mutants responded differently (Group 1), drugs to which all the mutants showed sensitivity (Group 2), and drugs to which all the mutants exhibited resistance (Group 3). The ability of the compounds to be partitioned to the plasma membrane seemed an important factor for recognition by Pdr5p.
Tutulan-Cunita
Andreea Cristina
AC
Department of Molecular Biotechnology, Graduate School of Advanced Sciences of Matter, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8530, Japan.
Mikoshi
Makoto
M
Mizunuma
Masaki
M
Hirata
Dai
D
Miyakawa
Tokichi
T
D018528:ATP-Binding Cassette Transporters / Q000235:genetics* / Q000378:metabolism; D004252:DNA Mutational Analysis; D018432:Drug Resistance, Multiple / Q000235:genetics* / Q000502:physiology; D009154:Mutation; D010641:Phenotype; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics* / Q000378:metabolism
D018528:ATP-Binding Cassette Transporters; C092438:PDR5 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins