Exocytosis in the budding yeast Saccharomyces cerevisiae occurs at discrete domains of the plasma membrane. The protein complex that tethers incoming vesicles to sites of secretion is known as the exocyst. We have used photobleaching recovery experiments to characterize the dynamic behavior of the eight subunits that make up the exocyst. One subset (Sec5p, Sec6p, Sec8p, Sec10p, Sec15p, and Exo84p) exhibits mobility similar to that of the vesicle-bound Rab family protein Sec4p, whereas Sec3p and Exo70p exhibit substantially more stability. Disruption of actin assembly abolishes the ability of the first subset of subunits to recover after photobleaching, whereas Sec3p and Exo70p are resistant. Immunogold electron microscopy and epifluorescence video microscopy indicate that all exocyst subunits, except for Sec3p, are associated with secretory vesicles as they arrive at exocytic sites. Assembly of the exocyst occurs when the first subset of subunits, delivered on vesicles, joins Sec3p and Exo70p on the plasma membrane. Exocyst assembly serves to both target and tether vesicles to sites of exocytosis.
Skip Nav Destination
Article navigation
6 December 2004
Article|
December 06 2004
Vesicles carry most exocyst subunits to exocytic sites marked by the remaining two subunits, Sec3p and Exo70p
Charles Boyd,
Charles Boyd
1Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06520
Search for other works by this author on:
Thom Hughes,
Thom Hughes
2Department of Cell Biology and Neuroscience, Montana State University, Bozeman, MT 59717
Search for other works by this author on:
Marc Pypaert,
Marc Pypaert
1Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06520
Search for other works by this author on:
Peter Novick
Peter Novick
1Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06520
Search for other works by this author on:
Charles Boyd
1Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06520
Thom Hughes
2Department of Cell Biology and Neuroscience, Montana State University, Bozeman, MT 59717
Marc Pypaert
1Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06520
Peter Novick
1Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06520
Correspondence to Peter Novick: [email protected]
Received:
August 20 2004
Accepted:
October 19 2004
Online ISSN: 1540-8140
Print ISSN: 0021-9525
The Rockefeller University Press
2004
J Cell Biol (2004) 167 (5): 889–901.
Article history
Received:
August 20 2004
Accepted:
October 19 2004
Citation
Charles Boyd, Thom Hughes, Marc Pypaert, Peter Novick; Vesicles carry most exocyst subunits to exocytic sites marked by the remaining two subunits, Sec3p and Exo70p . J Cell Biol 6 December 2004; 167 (5): 889–901. doi: https://doi.org/10.1083/jcb.200408124
Download citation file:
Sign in
Don't already have an account? Register
Client Account
You could not be signed in. Please check your email address / username and password and try again.
Could not validate captcha. Please try again.
Sign in via your Institution
Sign in via your InstitutionSuggested Content
Email alerts
Advertisement
Advertisement