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Sec6p anchors the assembled exocyst complex at sites of secretion
UMass Chan Affiliations
Department of Biochemistry and Molecular PharmacologyDocument Type
Journal ArticlePublication Date
2008-12-17Keywords
AllelesAmino Acid Sequence
Amino Acids
Carrier Proteins
Conserved Sequence
Exosomes
Models, Molecular
Molecular Sequence Data
Mutant Proteins
Mutation
Protein Binding
Protein Subunits
Protein Transport
Saccharomyces cerevisiae
Saccharomyces cerevisiae Proteins
Vesicular Transport Proteins
Life Sciences
Medicine and Health Sciences
Metadata
Show full item recordAbstract
The exocyst is an essential protein complex required for targeting and fusion of secretory vesicles to sites of exocytosis at the plasma membrane. To study the function of the exocyst complex, we performed a structure-based mutational analysis of the Saccharomyces cerevisiae exocyst subunit Sec6p. Two "patches" of highly conserved residues are present on the surface of Sec6p; mutation of either patch does not compromise protein stability. Nevertheless, replacement of SEC6 with the patch mutants results in severe temperature-sensitive growth and secretion defects. At nonpermissive conditions, although trafficking of secretory vesicles to the plasma membrane is unimpaired, none of the exocyst subunits are polarized. This is consistent with data from other exocyst temperature-sensitive mutants, which disrupt the integrity of the complex. Surprisingly, however, these patch mutations result in mislocalized exocyst complexes that remain intact. Our results indicate that assembly and polarization of the exocyst are functionally separable events, and that Sec6p is required to anchor exocyst complexes at sites of secretion.Source
Mol Biol Cell. 2009 Feb;20(3):973-82. Epub 2008 Dec 10. Link to article on publisher's site
DOI
10.1091/mbc.E08-09-0968Permanent Link to this Item
http://hdl.handle.net/20.500.14038/39380PubMed ID
19073882Related Resources
ae974a485f413a2113503eed53cd6c53
10.1091/mbc.E08-09-0968
Scopus Count
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