QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

Vol. 20, Issue 3, 973-982, February 1, 2009

This Article Full Text Full Text (PDF) All Versions of this Article: E08-09-0968v1 20/3/973    most recent Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Songer, J. A. Articles by Munson, M. Search for Related Content PubMed PubMed Citation Articles by Songer, J. A. Articles by Munson, M.

Sec6p Anchors the Assembled Exocyst Complex at Sites of Secretion

Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01605

Submitted September 23, 2008; Revised November 25, 2008; Accepted December 1, 2008
Monitoring Editor: Patrick J. Brennwald

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.

* Deceased.

Address correspondence to: Mary Munson (mary.munson{at}umassmed.edu)

Abbreviations used: SC, synthetic complete; ts, temperature sensitive.

This article has been cited by other articles:

				N. J. Andersen and C. Yeaman Sec3-containing Exocyst Complex Is Required for Desmosome Assembly in Mammalian Epithelial Cells Mol. Biol. Cell, January 1, 2010; 21(1): 152 - 164. [Abstract] [Full Text] [PDF]