Combinatorial SNARE complexes with VAMP7 or VAMP8 define different late endocytic fusion events
| Autor: | J. Paul Luzio, Barbara M. Mullock, Simon C. W. Richardson, Nicholas A. Bright, David E. James, Abigail Stewart, Sally R. Gray, Robert C. Piper, Margaret R. Lindsay, Paul R. Pryor |
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| Rok vydání: | 2004 |
| Předmět: |
Immunoprecipitation
Endosome Scientific Report Endocytic cycle Vesicular Transport Proteins Endosomes Biology Endocytosis Membrane Fusion PC12 Cells Biochemistry R-SNARE Proteins Lysosome Genetics medicine Animals Syntaxin Molecular Biology Cell-Free System Qa-SNARE Proteins Membrane Proteins Lipid bilayer fusion Rats Transport protein Cell biology Protein Transport medicine.anatomical_structure biological phenomena cell phenomena and immunity Lysosomes SNARE Proteins |
| Zdroj: | EMBO reports. 5:590-595 |
| ISSN: | 1469-3178 1469-221X |
| DOI: | 10.1038/sj.embor.7400150 |
| Popis: | Both heterotypic and homotypic fusion events are required to deliver endocytosed macromolecules to lysosomes and remodel late endocytic organelles. A trans-SNARE complex consisting of Q-SNAREs syntaxin 7, Vti1b and syntaxin 8 and the R-SNARE VAMP8 has been shown by others to be responsible for homotypic fusion of late endosomes. Using antibody inhibition experiments in rat liver cell-free systems, we confirmed this result, but found that the same Q-SNAREs can combine with an alternative R-SNARE, namely VAMP7, for heterotypic fusion between late endosomes and lysosomes. Co-immunoprecipitation demonstrated separate syntaxin 7 complexes with either VAMP7 or VAMP8 in solubilized rat liver membranes. Additionally, overexpression of the N-terminal domain of VAMP7, in cultured fibroblastic cells, inhibited the mixing of a preloaded lysosomal content marker with a marker delivered to late endosomes. These data show that combinatorial interactions of SNAREs determine whether late endosomes undergo homotypic or heterotypic fusion events. |
| Databáze: | OpenAIRE |
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