Actin cytoskeleton reorganization by Syk regulates Fc? receptor responsiveness by increasing its lateral mobility and clustering.

ABSTRACT: Clustering of immunoreceptors upon association with multivalent ligands triggers important responses including phagocytosis, secretion of cytokines, and production of immunoglobulins. We applied single-molecule detection and tracking methods to study the factors that control the mobility and clustering of phagocytic Fc? receptors (Fc?R). While the receptors exist as monomers in resting macrophages, two distinct populations were discernible based on their mobility: some diffuse by apparent free motion, while others are confined within submicron boundaries that reduce the frequency of spontaneous collisions. Src-family and Syk kinases determine the structure of the actin cytoskeleton, which is fenestrated, accounting for the heterogeneous diffusion of the Fc?R. Stimulation of these kinases during phagocytosis induces reorganization of the cytoskeleton both locally and distally in a manner that alters receptor mobility and clustering, generating a feedback loop that facilitates engagement of Fc?R at the tip of pseudopods, directing the progression of phagocytosis.

SUBMITTER: Jaumouille V 

PROVIDER: S-EPMC4083245 | biostudies-literature | 2014 Jun

REPOSITORIES: biostudies-literature