Article abstract
Nature Cell Biology 3, 235 - 244 (2001)
Published online: 1 February 2001 | doi:10.1038/35060020
Role of actin polymerization and actin cables in actin-patch movement in Schizosaccharomyces pombe
Robert J. Pelham, Jr1 & Fred Chang1
Abstract
Factors that are involved in actin polymerization, such as the Arp2/3 complex, have been found to be packaged into discrete, motile, actin-rich foci. Here we investigate the mechanism of actin-patch motility in S. pombe using a fusion of green fluorescent protein (GFP) to a coronin homologue, Crn1p. Actin patches are associated with cables and move with rates of 0.32 
m s-1 primarily in an undirected manner at cell tips and also in a directed manner along actin cables, often away from cell tips. Patches move more slowly or stop when actin polymerization is attenuated by Latrunculin A or in arp3 and cdc3 (profilin) mutants. In a cdc8 (tropomyosin) mutant, actin cables are absent, and patches move with similar speed but in a non-directed manner. Patches are sites of Arp3-dependent F-actin polymerization in vitro. Rapid F-actin turnover rates in vivo indicate that patches and cables are maintained continuously by actin polymerization. Our studies give rise to a model in which actin patches are centres for actin polymerization that drive their own movement on actin cables using Arp2/3-based actin polymerization.
- Department of Microbiology, Columbia University College of Physicians and Surgeons, 701 West 168th Street, New York, New York 10032, USA
Correspondence to: Fred Chang1 e-mail: fc99@columbia.edu
