Figure 8.

Model showing how S100A4 impacts CSF-1 signaling in macrophages. Pyk2 activation is mediated by calcium signaling (1) and cytoskeletal integrity (2). Activated Pyk2 promotes paxillin phosphorylation on pY118, and the recruitment of intermediary signaling molecules that recruit and activate Rac, which modulates the formation of adhesions as well as protrusive activity. The loss of S100A4 results in actomyosin overassembly and may alter local calcium dynamics near the plasma membrane, resulting in hyperactivation of Pyk2 and associated dysregulation of downstream signaling events.