title: Membranes linked by trans-SNARE complexes require lipids prone to non-bilayer structure for progression to fusion.
abstract: Like other intracellular fusion events, the homotypic fusion of yeast vacuoles requires a Rab GTPase, a large Rab effector complex, SNARE proteins which can form a 4-helical bundle, and the SNARE disassembly chaperones Sec17p and Sec18p. In addition to these proteins, specific vacuole lipids are required for efficient fusion in vivo and with the purified organelle. Reconstitution of vacuole fusion with all purified components reveals that high SNARE levels can mask the requirement for a complex mixture of vacuole lipids. At lower, more physiological SNARE levels, neutral lipids with small headgroups that tend to form non-bilayer structures (phosphatidylethanolamine, diacylglycerol, and ergosterol) are essential. Membranes without these three lipids can dock and complete trans-SNARE pairing but cannot rearrange their lipids for fusion. DOI: http://dx.doi.org/10.7554/eLife.01879.001.
authors.affiliation: Department of Biochemistry, Geisel School of Medicine at Dartmouth, Hanover, United States.
authors.forename: Michael
authors.initials: M
authors.lastname: Zick
authors.forename: Christopher
authors.initials: C
authors.lastname: Stroupe
authors.forename: Amy
authors.initials: A
authors.lastname: Orr
authors.forename: Deborah
authors.initials: D
authors.lastname: Douville
authors.forename: William T
authors.initials: WT
authors.lastname: Wickner
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism; D001665:Binding Sites; D008561:Membrane Fusion; D008563:Membrane Lipids / Q000737:chemistry / Q000378:metabolism*; D008567:Membranes, Artificial; D015394:Molecular Structure; D011485:Protein Binding; D011487:Protein Conformation; D011510:Proteolipids / Q000378:metabolism; D050682:Q-SNARE Proteins / Q000737:chemistry / Q000378:metabolism*; D050683:R-SNARE Proteins / Q000737:chemistry / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism; D052067:Soluble N-Ethylmaleimide-Sensitive Factor Attachment Proteins / Q000378:metabolism; D013997:Time Factors; D014617:Vacuoles / Q000737:chemistry / Q000378:metabolism*; D033921:Vesicular Transport Proteins / Q000378:metabolism
chemical_list: D008563:Membrane Lipids; D008567:Membranes, Artificial; D011510:Proteolipids; D050682:Q-SNARE Proteins; D050683:R-SNARE Proteins; C075137:SEC17 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D052067:Soluble N-Ethylmaleimide-Sensitive Factor Attachment Proteins; D033921:Vesicular Transport Proteins; C020485:proteoliposomes; D000251:Adenosine Triphosphatases; C064404:SEC18 protein, S cerevisiae
keywords: SNAREs; diacylglycerol; ergosterol; membrane fusion; phosphatidylethanolamine