Molecular Biology of the Cell Call for Nominations: MBC Editor-in-Chief

Home Help [Feedback] [For Subscribers] [Archive] [Search] --
QUICK SEARCH:   [advanced]


     

MBC in Press, published online ahead of print June 27, 2007
Mol. Biol. Cell 10.1091/mbc.E07-01-0024

A more recent version of this article appeared on September 1, 2007
This Article
Right arrow Full Text (PDF)
Right arrow All Versions of this Article:
E07-01-0024v1
18/9/3502    most recent
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Larina, O.
Right arrow Articles by Thorn, P.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Larina, O.
Right arrow Articles by Thorn, P.

Submitted on January 12, 2007
Revised on June 12, 2007
Accepted on June 20, 2007

Dynamic Regulation of the Large Exocytotic Fusion Pore in Pancreatic Acinar Cells

Olga Larina,*{dagger} Purnima Bhat,{dagger}{ddagger} James A. Pickett,* Bradley S. Launikonis,{ddagger} Amit Shah,* Wade A. Kruger,{ddagger} J. Michael Edwardson,* and Peter Thorn{ddagger}

*Department of Pharmacology, University of Cambridge, Cambridge, CB2 1PD, United Kingdom; {ddagger}School of Biomedical Sciences, University of Queensland, Brisbane, QLD 4072, Australia

Monitoring Editor: Tom U. Martin

Loss of granule content during exocytosis requires the opening of a fusion pore between the secretory granule and plasma membrane. In a variety of secretory cells this fusion pore has now been shown to subsequently close. However, it is still unclear how pore closure is physiologically regulated and contentious as to how closure relates to granule content loss. Here we examine the behavior of the fusion pore during zymogen granule exocytosis in pancreatic acinar cells. Using entry of high molecular weight dyes from the extracellular solution into the granule lumen, we show that the fusion pore has a diameter of 29-55 nm. We further show that by 5 min after granule fusion, many granules have a closed fusion pore with evidence indicating that pore closure is a prelude to endocytosis, and that in granules with a closed fusion pore the chymotrypsinogen content is low. Finally, we show that Latrunculin B treatment promotes pore closure, suggesting F-actin affects pore dynamics. Taken together our data do not support the classical view in acinar cells that exocytosis ends with granule collapse. Instead, for many granules the fusion pore closes, probably as a transition to endocytosis, and likely involving an F-actin dependent mechanism.

{dagger}These authors contributed equally to this work.

Address correspondence to: Peter Thorn (p.thorn{at}uq.edu.au)




This article has been cited by other articles:


Home page
 J. Cell Sci.Home page
A. Chen, E. Leikina, K. Melikov, B. Podbilewicz, M. M. Kozlov, and L. V. Chernomordik
Fusion-pore expansion during syncytium formation is restricted by an actin network
J. Cell Sci., November 1, 2008; 121(21): 3619 - 3628.
[Abstract] [Full Text] [PDF]

Home page
 J. Physiol.Home page
J. N. Edwards and B. S. Launikonis
The accessibility and interconnectivity of the tubular system network in toad skeletal muscle
J. Physiol., November 1, 2008; 586(21): 5077 - 5089.
[Abstract] [Full Text] [PDF]


Home Help [Feedback] [For Subscribers] [Archive] [Search] --
Copyright © 2007 by The American Society for Cell Biology. Terms of copyright protection, warranties, and disclaimers.