Actin-binding protein that enhances membrane ruffling and RAC activation. Enhances the actin-bundling activity of LCP1. Binds calcium. Plays a role in RAC signaling and in phagocytosis. May play a role in macrophage activation and function. Promotes the proliferation of vascular smooth muscle cells and of T-lymphocytes. Enhances lymphocyte migration. Plays a role in vascular inflammation. Homodimer (Potential). Monomer. Interacts with LCP1. Associated with the actin cytoskeleton at membrane ruffles and at sites of phagocytosis. Detected in T-lymphocytes and peripheral blood mononuclear cells. Phosphorylated on serine residues.