spacer gif spacer gif spacer gif spacer gif spacer gif
QUICK SEARCH:   [advanced]


spacer gif
     Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents    

First published online 11 December 2007
doi: 10.1242/jcs.013383

Journal of Cell Science 121, 55-64 (2008)
Published by The Company of Biologists 2008
This Article
Right arrow Figures Only
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Supplementary Material
Right arrow All Versions of this Article:
jcs.013383v1
121/1/55    most recent
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Related articles in JCS
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 Google Scholar
Google Scholar
Right arrow Articles by Heinzer, S.
Right arrow Articles by Weiss, M.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Heinzer, S.
Right arrow Articles by Weiss, M.

Research Article

A model for the self-organization of exit sites in the endoplasmic reticulum

Stephan Heinzer1, Stefan Wörz2,3, Claudia Kalla1, Karl Rohr2,3 and Matthias Weiss1,*

1 Cellular Biophysics Group (BIOMS), German Cancer Research Center, Bioquant Center, Im Neuenheimer Feld 267, D-69120 Heidelberg, Germany
2 Biomedical Computer Vision Group, Department of Bioinformatics and Functional Genomics, IPMB, University of Heidelberg, Im Neuenheimer Feld 267, D-69120 Heidelberg, Germany
3 German Cancer Research Center, D-69120 Heidelberg, Germany

* Author for correspondence (e-mail: m.weiss{at}dkfz.de)

Accepted 17 October 2007

Exit sites (ES) are specialized domains of the endoplasmic reticulum (ER) at which cargo proteins of the secretory pathway are packaged into COPII-coated vesicles. Although the essential COPII proteins (Sar1p, Sec23p-Sec24p, Sec13p-Sec31p) have been characterized in detail and their sequential binding kinetics at ER membranes have been quantified, the basic processes that govern the self-assembly and spatial organization of ERES have remained elusive. Here, we have formulated a generic computational model that describes the process of formation of ERES on a mesoscopic scale. The model predicts that ERES are arranged in a quasi-crystalline pattern, while their size strongly depends on the cargo-modulated kinetics of COPII turnover – that is, a lack of cargo leads to smaller and more mobile ERES. These predictions are in favorable agreement with experimental data obtained by fluorescence microscopy. The model further suggests that cooperative binding of COPII components, for example mediated by regulatory proteins, is a key factor for the experimentally observed organism-specific ERES pattern. Moreover, the anterograde secretory flux is predicted to grow when the average size of ERES is increased, whereas an increase in the number of (small) ERES only slightly alters the flux.

Key words: Biophysical modelling, Domain formation, Membrane traffic, Systems biology


Related articles in JCS:

ERES keep their distance

JCS 2008 121: 103. [Full Text]  





© The Company of Biologists Ltd 2008