Identification and characterization of SNQ2, a new multidrug ATP binding cassette transporter of the yeast plasma membrane.
The SNQ2 gene of Saccharomyces cerevisiae, which encodes an ATP binding cassette protein responsible for resistance to the mutagen 4-nitroquinoline oxide, is regulated by the DNA-binding proteins PDR1 and PDR3. In a plasma membrane-enriched fraction from a pdr1 mutant, the SNQ2 protein is found in the 160-kDa over-expressed band, together with PDR5. The SNQ2 protein was solubilized with n-dodecyl beta-D-maltoside from the plasma membranes of a PDR5-deleted strain and separated from the PMA1 H(+/-)ATPase by sucrose gradient centrifugation. The enzyme shows a nucleoside triphosphatase activity that differs biochemically from that of PDR5 (Decottignies, A., Kolaczkowski, M., Balzi, E., and Goffeau, A. (1994) J. Biol. Chem. 269, 12797-12803) and is sensitive to vanadate, erythrosine B, and Triton X-100 but not to oligomycin, which inhibits the PDR5 activity only. Disruption of both PDR5 and SNQ2 in a pdr1 mutant decreases the cell growth rate and reveals the presence of at least two other ATP binding cassette proteins in the 160-kDa overexpressed band that have been identified by amino-terminal microsequencing.
Decottignies
A
A
Unité de Biochimie Physiologique, Université Catholique de Louvain, Belgium.
Lambert
L
L
Catty
P
P
Degand
H
H
Epping
E A
EA
Moye-Rowley
W S
WS
Balzi
E
E
Goffeau
A
A
D018528:ATP-Binding Cassette Transporters / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D002352:Carrier Proteins / Q000037:antagonists & inhibitors / Q000302:isolation & purification / Q000378:metabolism; D002455:Cell Division / Q000235:genetics; D002462:Cell Membrane / Q000378:metabolism; D017931:DNA Primers; D004268:DNA-Binding Proteins / Q000378:metabolism; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D006868:Hydrolysis; D008565:Membrane Proteins / Q000037:antagonists & inhibitors / Q000302:isolation & purification / Q000378:metabolism; D008969:Molecular Sequence Data; D011755:Pyrophosphatases / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins; D014158:Transcription, Genetic
D018528:ATP-Binding Cassette Transporters; D002352:Carrier Proteins; D017931:DNA Primers; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; D008565:Membrane Proteins; C092438:PDR5 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D011755:Pyrophosphatases; C023278:uridine triphosphatase