title: Generic sorting of raft lipids into secretory vesicles in yeast.
abstract: Previous work has showed that ergosterol and sphingolipids become sorted to secretory vesicles immunoisolated using a chimeric, artificial raft membrane protein as bait. In this study, we have extended this analysis to three populations of secretory vesicles isolated using natural yeast plasma membrane (PM) proteins: Pma1p, Mid2p and Gap1*p as baits. We compared the lipidomes of the immunoisolated vesicles with each other and with the lipidomes of the donor compartment, the trans-Golgi network, and the acceptor compartment, the PM, using a quantitative mass spectrometry approach that provided a complete lipid overview of the yeast late secretory pathway. We could show that vesicles captured with different baits carry the same cargo and have almost identical lipid compositions; being highly enriched in ergosterol and sphingolipids. This finding indicates that lipid raft sorting is a generic feature of vesicles carrying PM cargo and suggests a common lipid-based mechanism for their formation.
authors.affiliation: Max Planck Institute for Molecular Cell Biology and Genetics, Pfotenhauerstr 108, Dresden 01307, Germany.
authors.forename: Michal A
authors.initials: MA
authors.lastname: Surma
authors.forename: Christian
authors.initials: C
authors.lastname: Klose
authors.forename: Robin W
authors.initials: RW
authors.lastname: Klemm
authors.forename: Christer S
authors.initials: CS
authors.lastname: Ejsing
authors.forename: Kai
authors.initials: K
authors.lastname: Simons
mesh_terms: D026905:Amino Acid Transport Systems / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D004875:Ergosterol / Q000737:chemistry / Q000378:metabolism*; D047908:Intracellular Signaling Peptides and Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D050356:Lipid Metabolism; D013058:Mass Spectrometry; D008562:Membrane Glycoproteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D021962:Membrane Microdomains / Q000737:chemistry / Q000378:metabolism*; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006180:Proton-Translocating ATPases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D022142:Secretory Vesicles / Q000737:chemistry / Q000378:metabolism*; D013107:Sphingolipids / Q000737:chemistry / Q000378:metabolism*; D021601:trans-Golgi Network / Q000378:metabolism
chemical_list: D026905:Amino Acid Transport Systems; C491145:GAP1 protein, S cerevisiae; D047908:Intracellular Signaling Peptides and Proteins; C091625:MID2 protein, S cerevisiae; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D029701:Saccharomyces cerevisiae Proteins; D013107:Sphingolipids; C092477:PMA1 protein, S cerevisiae; D006180:Proton-Translocating ATPases; D004875:Ergosterol