Chemotaxis in shallow gradients is mediated independently of PtdIns 3-kinase by biased choices between random protrusions

Andrew, N. and Insall, R. H. (2007) Chemotaxis in shallow gradients is mediated independently of PtdIns 3-kinase by biased choices between random protrusions. Nature Cell Biology, 9(2), pp. 193-200. (doi:10.1038/ncb1536) (PMID:17220879)

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Abstract

Current models of eukaryotic chemotaxis propose that directional sensing causes localized generation of new pseudopods1. However, quantitative analysis of pseudopod generation suggests a fundamentally different mechanism for chemotaxis in shallow gradients: first, pseudopods in multiple cell types are usually generated when existing ones bifurcate and are rarely made de novo; second, in Dictyostelium cells in shallow chemoattractant gradients, pseudopods are made at the same rate whether cells are moving up or down gradients. The location and direction of new pseudopods are random within the range allowed by bifurcation and are not oriented by chemoattractants. Thus, pseudopod generation is controlled independently of chemotactic signalling. Third, directional sensing is mediated by maintaining the most accurate existing pseudopod, rather than through the generation of new ones. Finally, the phosphatidylinositol 3-kinase (PI(3)K) inhibitor LY294002 affects the frequency of pseudopod generation, but not the accuracy of selection, suggesting that PI(3)K regulates the underlying mechanism of cell movement, rather than control of direction.

Item Type:Articles (Letter)
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Insall, Professor Robert
Authors: Andrew, N., and Insall, R. H.
College/School:College of Medical Veterinary and Life Sciences > Institute of Cancer Sciences
Journal Name:Nature Cell Biology
Publisher:Nature Publishing Group
ISSN:1465-7392
ISSN (Online):1476-4679
Published Online:14 January 2007

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