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.
Publication types
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Research Support, Non-U.S. Gov't
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Biological Transport / genetics
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Fungal Proteins / genetics
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Fungal Proteins / metabolism*
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Gene Expression Regulation, Fungal*
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Genes, Fungal
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Glucose / metabolism*
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Glucose Transport Proteins, Facilitative
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Membrane Proteins / genetics
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Membrane Proteins / metabolism*
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Monosaccharide Transport Proteins / genetics
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Monosaccharide Transport Proteins / metabolism*
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Mutation
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Saccharomyces cerevisiae / genetics
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Saccharomyces cerevisiae / metabolism*
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Saccharomyces cerevisiae Proteins*
Substances
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Fungal Proteins
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Glucose Transport Proteins, Facilitative
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Gsf2 protein, S cerevisiae
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HXT1 protein, S cerevisiae
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Membrane Proteins
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Monosaccharide Transport Proteins
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Saccharomyces cerevisiae Proteins
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Glucose