title: The yeast oxysterol binding protein Kes1 maintains sphingolipid levels.
abstract: The oxysterol binding protein family are amphitropic proteins that bind oxysterols, sterols, and possibly phosphoinositides, in a conserved binding pocket. The Saccharomyces cerevisiae oxysterol binding protein family member Kes1 (also known as Osh4) also binds phosphoinositides on a distinct surface of the protein from the conserved binding pocket. In this study, we determine that the oxysterol binding protein family member Kes1 is required to maintain the ratio of complex sphingolipids and levels of ceramide, sphingosine-phosphate and sphingosine. This inability to maintain normal sphingolipid homeostasis resulted in misdistribution of Pma1, a protein that requires normal sphingolipid synthesis to occur to partition into membrane rafts at the Golgi for its trafficking to the plasma membrane.
authors.affiliation: Department of Pathology, Dalhousie University, Halifax, Nova Scotia, Canada.
authors.forename: Marissa A
authors.initials: MA
authors.lastname: LeBlanc
authors.forename: Gregory D
authors.initials: GD
authors.lastname: Fairn
authors.forename: Sarah B
authors.initials: SB
authors.lastname: Russo
authors.forename: Ola
authors.initials: O
authors.lastname: Czyz
authors.forename: Vanina
authors.initials: V
authors.lastname: Zaremberg
authors.forename: L Ashley
authors.initials: LA
authors.lastname: Cowart
authors.forename: Christopher R
authors.initials: CR
authors.lastname: McMaster
mesh_terms: D002462:Cell Membrane / Q000378:metabolism; D002518:Ceramides / Q000378:metabolism; D006056:Golgi Apparatus / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism*; D021381:Protein Transport; D006180:Proton-Translocating ATPases / Q000378:metabolism; D011987:Receptors, Steroid / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism*; D013107:Sphingolipids / Q000378:metabolism*; D000098825:Oxysterol Binding Proteins
chemical_list: D002518:Ceramides; C087901:KES1 protein, S cerevisiae; D008565:Membrane Proteins; D011987:Receptors, Steroid; D029701:Saccharomyces cerevisiae Proteins; D013107:Sphingolipids; D000098825:Oxysterol Binding Proteins; C092477:PMA1 protein, S cerevisiae; D006180:Proton-Translocating ATPases