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| EMBO J. Nov (2006); 25(22):5260-9 | |
| Reversible, cooperative reactions of yeast vacuole docking- | |
| Jun Y, Thorngren N, Starai VJ, Fratti RA, Collins K, Wickner W | |
| Department of Biochemistry, Dartmouth Medical School, Hanover, NH 03755, USA- | |
| Abstract: Homotypic yeast vacuole fusion occurs in three stages- -i- priming reactions, which are independent of vacuole clustering, -ii- docking, in which vacuoles cluster and accumulate fusion proteins and fusion regulatory lipids at a ring-shaped microdomain surrounding the apposed membranes of each docked vacuole, where fusion will occur, and -iii- bilayer fusion-compartment mixing- These stages require vacuolar SNAREs, SNARE-chaperones, GTPases, effector complexes, and chemically minor but functionally important lipids- For each, we have developed specific ligands that block fusion and conditions that reverse each block- Using them, we test whether docking entails a linearly ordered series of catalytic events, marked by sequential acquisition of resistance to inhibitors, or whether docking subreactions are cooperative and-or reversible- We find that each fusion protein and regulatory lipid is needed throughout docking, indicative of a reversible or highly cooperative assembly of the fusion-competent vertex ring- In accord with this cooperativity, vertices enriched in one fusion catalyst are enriched in others- Docked vacuoles finally assemble SNARE complexes, yet still require physiological temperature and lipid rearrangements to complete fusion- | |
| [PUBMED: 17082764] |   |
| Copyright © 2009, Tyers Lab, The Samuel Lunenfeld Research Institute, Mount Sinai Hospital, All Rights Reserved. |
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| BioGRID: A General Repository for Interaction Datasets. Chris Stark, Bobby-Joe Breitkreutz, Teresa Reguly, Lorrie Boucher, Ashton Breitkreutz, Mike Tyers. Nucleic Acids Res. Jan 1;34:D535-9. |