Publication Date:
2008-08-16
Description:
Diverse cell polarity networks require positive feedback for locally amplifying distributions of signalling molecules at the plasma membrane. Additional mechanisms, such as directed transport or coupled inhibitors, have been proposed to be required for reinforcing a unique axis of polarity. Here we analyse a simple model of positive feedback, with strong analogy to the 'stepping stone' model of population genetics, in which a single species of diffusible, membrane-bound signalling molecules can self-recruit from a cytoplasmic pool. We identify an intrinsic stochastic mechanism through which positive feedback alone is sufficient to account for the spontaneous establishment of a single site of polarity. We find that the polarization frequency has an inverse dependence on the number of signalling molecules: the frequency of polarization decreases as the number of molecules becomes large. Experimental observation of polarizing Cdc42 in budding yeast is consistent with this prediction. Our work suggests that positive feedback can work alone or with additional mechanisms to create robust cell polarity.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2562338/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉 〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2562338/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Altschuler, Steven J -- Angenent, Sigurd B -- Wang, Yanqin -- Wu, Lani F -- R01 GM071794/GM/NIGMS NIH HHS/ -- R01 GM071794-05/GM/NIGMS NIH HHS/ -- England -- Nature. 2008 Aug 14;454(7206):886-9. doi: 10.1038/nature07119.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Green Center for Systems Biology, Department of Pharmacology and Simmons Cancer Center, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA. steven.altschuler@utsouthwestern.edu〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18704086" target="_blank"〉PubMed〈/a〉
Keywords:
Cell Polarity/*physiology
;
Computer Simulation
;
Feedback, Physiological
;
Models, Biological
;
Models, Molecular
;
Saccharomyces cerevisiae/*cytology/*metabolism
;
Signal Transduction
;
cdc42 GTP-Binding Protein, Saccharomyces cerevisiae/*metabolism
Print ISSN:
0028-0836
Electronic ISSN:
1476-4687
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
,
Natural Sciences in General
,
Physics
