Document Type
Article
Publication Date
12-20-2004
Publication Title
The Journal of Cell Biology
Department
Geisel School of Medicine
Abstract
Membrane microdomains are assembled by lipid partitioning (e.g., rafts) or by protein-protein interactions (e.g., coated vesicles). During docking, yeast vacuoles assemble "vertex" ring-shaped microdomains around the periphery of their apposed membranes. Vertices are selectively enriched in the Rab GTPase Ypt7p, the homotypic fusion and vacuole protein sorting complex (HOPS)-VpsC Rab effector complex, SNAREs, and actin. Membrane fusion initiates at vertex microdomains. We now find that the "regulatory lipids" ergosterol, diacylglycerol and 3- and 4-phosphoinositides accumulate at vertices in a mutually interdependent manner. Regulatory lipids are also required for the vertex enrichment of SNAREs, Ypt7p, and HOPS. Conversely, SNAREs and actin regulate phosphatidylinositol 3-phosphate vertex enrichment. Though the PX domain of the SNARE Vam7p has direct affinity for only 3-phosphoinositides, all the regulatory lipids which are needed for vertex assembly affect Vam7p association with vacuoles. Thus, the assembly of the vacuole vertex ring microdomain arises from interdependent lipid and protein partitioning and binding rather than either lipid partitioning or protein interactions alone.
DOI
10.1083/jcb.200409068
Original Citation
Fratti RA, Jun Y, Merz AJ, Margolis N, Wickner W. Interdependent assembly of specific regulatory lipids and membrane fusion proteins into the vertex ring domain of docked vacuoles. J Cell Biol. 2004 Dec 20;167(6):1087-98. doi: 10.1083/jcb.200409068. PMID: 15611334; PMCID: PMC2172599.
Dartmouth Digital Commons Citation
Fratti, Rutilio A.; Jun, Youngsoo; Merz, Alexey J.; Margolis, Nathan; and Wickner, William, "Interdependent Assembly of Specific Regulatory Lipids and Membrane Fusion Proteins into the Vertex Ring Domain of Docked Vacuoles" (2004). Dartmouth Scholarship. 1452.
https://digitalcommons.dartmouth.edu/facoa/1452
