Letter abstract
Nature Cell Biology 9, 193 - 200 (2007)
Published online: 14 January 2007 | doi:10.1038/ncb1536
Chemotaxis in shallow gradients is mediated independently of PtdIns 3-kinase by biased choices between random protrusions
Natalie Andrew1 & Robert H Insall1
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.
- School of Biosciences, The University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK.
Correspondence to: Robert H Insall1 e-mail: r.h.insall@bham.ac.uk
MORE ARTICLES LIKE THIS
These links to content published by NPG are automatically generated.
NEWS AND VIEWS
Rho Rocks PTENNature Cell Biology News and Views (01 Apr 2005)
Leading the wayNature Cell Biology News and Views (01 Jul 2002)
See all 11 matches for News And ViewsRESEARCH
Ca 2+ signalling is not required for chemotaxis in DictyosteliumThe EMBO Journal Article (01 Sep 2000)
See all 46 matches for Research