title: A member of the sugar transporter family, Stl1p is the glycerol/H+ symporter in Saccharomyces cerevisiae.
abstract: Glycerol and other polyols are used as osmoprotectants by many organisms. Several yeasts and other fungi can take up glycerol by proton symport. To identify genes involved in active glycerol uptake in Saccharomyces cerevisiae we screened a deletion mutant collection comprising 321 genes encoding proteins with 6 or more predicted transmembrane domains for impaired growth on glycerol medium. Deletion of STL1, which encodes a member of the sugar transporter family, eliminates active glycerol transport. Stl1p is present in the plasma membrane in S. cerevisiae during conditions where glycerol symport is functional. Both the Stl1 protein and the active glycerol transport are subject to glucose-induced inactivation, following identical patterns. Furthermore, the Stl1 protein and the glycerol symporter activity are strongly but transiently induced when cells are subjected to osmotic shock. STL1 was heterologously expressed in Schizosaccharomyces pombe, a yeast that does not contain its own active glycerol transport system. In S. pombe, STL1 conferred the ability to take up glycerol against a concentration gradient in a proton motive force-dependent manner. We conclude that the glycerol proton symporter in S. cerevisiae is encoded by STL1.
authors.affiliation: Carlsberg Laboratory, Copenhagen Valby, Denmark.
authors.forename: Célia
authors.initials: C
authors.lastname: Ferreira
authors.forename: Frank
authors.initials: F
authors.lastname: van Voorst
authors.forename: António
authors.initials: A
authors.lastname: Martins
authors.forename: Luisa
authors.initials: L
authors.lastname: Neves
authors.forename: Rui
authors.initials: R
authors.lastname: Oliveira
authors.forename: Morten C
authors.initials: MC
authors.lastname: Kielland-Brandt
authors.forename: Cândida
authors.initials: C
authors.lastname: Lucas
authors.forename: Anders
authors.initials: A
authors.lastname: Brandt
mesh_terms: D001692:Biological Transport / Q000187:drug effects; D050260:Carbohydrate Metabolism; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D005947:Glucose / Q000494:pharmacology; D005990:Glycerol / Q000378:metabolism*; D006859:Hydrogen / Q000378:metabolism*; D026901:Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism*; D009154:Mutation / Q000235:genetics; D009997:Osmotic Pressure; D011522:Protons; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D012568:Schizosaccharomyces / Q000235:genetics / Q000378:metabolism
chemical_list: D026901:Membrane Transport Proteins; D011522:Protons; C470555:STL1 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D006859:Hydrogen; D005947:Glucose; D005990:Glycerol