ABSTRACT
PSTPIPl and PSTPIP2 are expressed predominantly in the hematopoietic system where their C-terminal tyrosine phosphorylation is regulated by PEST family phosphatases. Both proteins deform membranes via their conserved F-BAR domains and regulate actin organization, but their actin regulatory activities differ. PSTPIPl negatively regulates actin po lymerization by recruiting PTP-PEST to WASP and mediating dephosphorylation o f WASP at Y291. PSTPIP2 bundles actin and increases filopodia formation. Mutations in human PSTPIPl and mouse PSTPIP2 cause autoinflammatory diseases. Analysis o f the actions o f these proteins promises to reveal novel mechanisms for the regulation o f the inflammatory response involving macrophages and osteoclasts.
