Chemoattractant receptor–stimulated F-actin polymerization in the human neutrophil is signaled by 2 distinct pathways

Abstract

AbstractWe characterized the overall rate of F-actin polymerization in the pseudopod region by measuring the rate of extension of single pseudopods stimulated by f-Met-Leu-Phe. The rate of pseudopod extension was measured in the presence of inhibitors for signaling molecules that are known to be involved in motility. Our data show the existence of 2 distinct signaling pathways of actin polymerization in the pseudopod region: a phosphoinositide 3-kinase γ (PI3Kγ)–dependent and –independent pathway. The PI3Kγ dependent signaling of F-actin polymerization also depends on protein kinase C ζ and protein kinase B (Akt/PKB). The PI3Kγ-independent pathway depends on GTPase RhoA, the RhoA ROCK kinase, Src family tyrosine kinases, and NADPH, and is modulated by cAMP.