Proline Serine Threonine Phosphatase Interacting Protein 1 (PSTPIP1)

PSTPIP1, an effector of T cell activation and adhesion, negatively affecting CD2-triggered T cell activation. The encoded protein appears to be a scaffold protein and a regulator of the actin cytoskeleton. It has also been shown to bind ABL1, PTPN18, WAS, CD2AP, and PTPN12. Mutations in this gene are a cause of PAPA syndrome.The full-length 417-amino acid protein, which is 88% identical to mouse Pstpip1, contains a coiled-coil region, which is 30% identical to yeast Cdc15, a PEST region, and a C-terminal SH3 domain. Compared with full-length CD2BP1, the shorter variant has a 19-amino acid deletion. Fluorescence microscopy demonstrated localization of CD2BP1 at the interface of the cytosol and the plasma membrane and colocalization with CD2 after ligand-induced clustering of surface CD2.