Article abstract
Nature Cell Biology 1, 75 - 81 (1999)
Published online: 15 May 1999 | doi:10.1038/10042
Spatial control of actin polymerization during neutrophil chemotaxis
Orion D. Weiner1,2, Guy Servant2, Matthew D. Welch2,3, Timothy J. Mitchison2,4, John W. Sedat1 & Henry R. Bourne2
Abstract
Neutrophils respond to chemotactic stimuli by increasing the nucleation and polymerization of actin filaments, but the location and regulation of these processes are not well understood. Here, using a permeabilized-cell assay, we show that chemotactic stimuli cause neutrophils to organize many discrete sites of actin polymerization, the distribution of which is biased by external chemotactic gradients. Furthermore, the Arp2/3 complex, which can nucleate actin polymerization, dynamically redistributes to the region of living neutrophils that receives maximal chemotactic stimulation, and the least-extractable pool of the Arp2/3 complex co-localizes with sites of actin polymerization. Our observations indicate that chemoattractant-stimulated neutrophils may establish discrete foci of actin polymerization that are similar to those generated at the posterior surface of the intracellular bacterium Listeria monocytogenes. We propose that asymmetrical establishment and/or maintenance of sites of actin polymerization produces directional migration of neutrophils in response to chemotactic gradients.
- Department of Biochemistry and Biophysics, University of California, San Francisco, California 94143-0554 , USA
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, California 94143-0450, USA
- Present address: Department of Molecular and Cell Biology, University of California, Berkeley, California 94720 , USA
- Present address: Department of Cell Biology, Harvard Medical School, 240 Longwood Avenue, Boston, Massachusetts 02115, USA
Correspondence to: Henry R. Bourne2 e-mail: h_bourne@quickmail.ucsf.edu
