RRC ID 29085
Author Langridge PD, Kay RR.
Title Mutants in the Dictyostelium Arp2/3 complex and chemoattractant-induced actin polymerization.
Journal Exp. Cell Res.
Abstract We have investigated the role of the Arp2/3 complex in Dictyostelium cell chemotaxis towards cyclic-AMP and in the actin polymerization that is triggered by this chemoattractant. We confirm that the Arp2/3 complex is recruited to the cell perimeter, or into a pseudopod, after cyclic-AMP stimulation and that this is coincident with actin polymerization. This recruitment is inhibited when actin polymerization is blocked using latrunculin suggesting that the complex binds to pre-existing actin filaments, rather than to a membrane associated signaling complex. We show genetically that an intact Arp2/3 complex is essential in Dictyostelium and have produced partially active mutants in two of its subunits. In these mutants both phases of actin polymerization in response to cyclic-AMP are greatly reduced. One mutant projects pseudopodia more slowly than wild type and has impaired chemotaxis, together with slower movement. The second mutant chemotaxes poorly due to an adhesion defect, suggesting that the Arp2/3 complex plays a crucial part in adhering cells to the substratum as they move. We conclude that the Arp2/3 complex largely mediates the actin polymerization response to chemotactic stimulation and contributes to cell motility, pseudopod extension and adhesion in Dictyostelium chemotaxis.
Volume 313(12)
Pages 2563-74
Published 2007-7-15
DOI 10.1016/j.yexcr.2007.04.029
PII S0014-4827(07)00202-9
PMID 17553489
MeSH Actin-Related Protein 2-3 Complex / genetics Actin-Related Protein 2-3 Complex / metabolism* Actins / chemistry* Actins / metabolism* Animals Cell Adhesion / drug effects Chemotactic Factors / pharmacology* Chemotaxis / drug effects Cyclic AMP / pharmacology Cytoskeleton / drug effects Dictyostelium / cytology Dictyostelium / drug effects* Dictyostelium / metabolism* Mutagenesis Mutation / genetics* Protein Structure, Quaternary / drug effects Protein Subunits / metabolism Pseudopodia / drug effects Recombinant Fusion Proteins / metabolism
IF 3.309
Times Cited 14
Cellular slime molds S00333