Sec1p directly stimulates SNARE-mediated membrane fusion in vitro
| Autor: | Brenton L. Scott, Kirilee A. Wilson, Song Liu, James A. McNew, Hassan Irshad, Jeffrey S. Van Komen |
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| Rok vydání: | 2004 |
| Předmět: |
Munc18 Proteins
Saccharomyces cerevisiae Proteins Time Factors Saccharomyces cerevisiae Oligonucleotides Vesicular Transport Proteins Golgi Apparatus Nerve Tissue Proteins Plasma protein binding Membrane Fusion Article Cell membrane 03 medical and health sciences symbols.namesake 0302 clinical medicine medicine Escherichia coli Secretion Fluorescent Antibody Technique Indirect Research Articles 030304 developmental biology Glutathione Transferase 0303 health sciences biology Dose-Response Relationship Drug Cell Membrane Temperature Lipid bilayer fusion Cell Biology Golgi apparatus biology.organism_classification Recombinant Proteins Cell biology medicine.anatomical_structure symbols SNARE complex SNARE Proteins 030217 neurology & neurosurgery Plasmids Protein Binding |
| Zdroj: | The Journal of Cell Biology |
| ISSN: | 0021-9525 |
| Popis: | Sec1 proteins are critical players in membrane trafficking, yet their precise role remains unknown. We have examined the role of Sec1p in the regulation of post-Golgi secretion in Saccharomyces cerevisiae. Indirect immunofluorescence shows that endogenous Sec1p is found primarily at the bud neck in newly budded cells and in patches broadly distributed within the plasma membrane in unbudded cells. Recombinant Sec1p binds strongly to the t-SNARE complex (Sso1p/Sec9c) as well as to the fully assembled ternary SNARE complex (Sso1p/Sec9c;Snc2p), but also binds weakly to free Sso1p. We used recombinant Sec1p to test Sec1p function using a well-characterized SNARE-mediated membrane fusion assay. The addition of Sec1p to a traditional in vitro fusion assay moderately stimulates fusion; however, when Sec1p is allowed to bind to SNAREs before reconstitution, significantly more Sec1p binding is detected and fusion is stimulated in a concentration-dependent manner. These data strongly argue that Sec1p directly stimulates SNARE-mediated membrane fusion. |
| Databáze: | OpenAIRE |
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