Title: | The yeast STE6 gene encodes a homologue of the mammalian multidrug resistance P-glycoprotein |
Author(s): | McGrath JP; Varshavsky A; |
Address: | "Department of Biology, Massachusetts Institute of Technology, Cambridge 02139" |
ISSN/ISBN: | 0028-0836 (Print) 0028-0836 (Linking) |
Abstract: | "Mammalian tumours displaying multidrug resistance overexpress a plasma membrane protein (P-glycoprotein), which is encoded by the MDR1 gene and apparently functions as an energy-dependent drug efflux pump. Tissue-specific expression of MDR1 and other members of the MDR gene family has been observed in normal cells, suggesting a role for P-glycoproteins in secretion. We have isolated a gene from the yeast Saccharomyces cerevisiae that encodes a protein very similar to mammalian P-glycoproteins. Deletion of this gene resulted in sterility of MATa, but not of MAT alpha cells. Subsequent analysis revealed that the yeast P-glycoprotein is the product of the STE6 gene, a locus previously shown to be required in MATa cells for production of a-factor pheromone. Our findings suggest that the STE6 protein functions to export the hydrophobic a-factor lipopeptide in a manner analogous to the efflux of hydrophobic cytotoxic drugs catalysed by the related mammalian P-glycoprotein. Thus, the evolutionarily conserved family of MDR-like genes, including the hlyB gene of Escherichia coli and the STE6 gene of S. cerevisiae, encodes components of secretory pathways distinct from the classical, signal sequence-dependent protein translocation system" |
Keywords: | "ATP Binding Cassette Transporter, Subfamily B, Member 1 *ATP-Binding Cassette Transporters Amino Acid Sequence Base Sequence Drug Resistance/*genetics Escherichia coli/genetics Fungal Proteins/genetics/metabolism Genes, Bacterial *Genes, Fungal *Glycoprot;" |
Notes: | "MedlineMcGrath, J P Varshavsky, A eng Comparative Study Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, P.H.S. England 1989/08/03 Nature. 1989 Aug 3; 340(6232):400-4. doi: 10.1038/340400a0" |