title: Efficient export of the glucose transporter Hxt1p from the endoplasmic reticulum requires Gsf2p.
abstract: Mutations in the GSF2 gene cause glucose starvation phenotypes in Saccharomyces cerevisiae. We have isolated the HXT1 gene, which encodes a low-affinity, high-capacity glucose transporter, as a multicopy suppressor of a gsf2 mutation. We show that gsf2 mutants accumulate Hxt1p in the endoplasmic reticulum (ER) and that Gsf2p is a 46-kDa integral membrane protein localized to the ER. gsf2 mutants also display a galactose growth defect and abnormal localization of the galactose transporter Gal2p but are not defective in function or localization of the high-affinity glucose transporter Hxt2p. These findings suggest that Gsf2p functions in the ER to promote the secretion of certain hexose transporters.
authors.affiliation: Department of Genetics and Development, Columbia University, New York, NY 10032, USA.
authors.forename: P W
authors.initials: PW
authors.lastname: Sherwood
authors.forename: M
authors.initials: M
authors.lastname: Carlson
mesh_terms: D001692:Biological Transport / Q000235:genetics; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D015966:Gene Expression Regulation, Fungal; D005800:Genes, Fungal; D005947:Glucose / Q000378:metabolism*; D051246:Glucose Transport Proteins, Facilitative; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D009004:Monosaccharide Transport Proteins / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins
chemical_list: D005656:Fungal Proteins; D051246:Glucose Transport Proteins, Facilitative; C120037:Gsf2 protein, S cerevisiae; C090594:HXT1 protein, S cerevisiae; D008565:Membrane Proteins; D009004:Monosaccharide Transport Proteins; D029701:Saccharomyces cerevisiae Proteins; D005947:Glucose