Differential association of cytoplasmic signalling molecules SHP-1, SHP-2, SHIP and phospholipase C-γl with PECAM-1/CD31

Recent studies have shown that, in addition to its role as an adhesion receptor, platelet endothelial cell adhesion molecule 1/CD31 becomes phosphorylated on tyrosine residues Y-663 and Y-686 and associates with protein tyrosine phosphatases SHP-1 and SHP-2, In this study, we screened for additional proteins which associate with phosphorylated platelet endothelial cell adhesion molecule 1, using surface plasmon resonance. We found that, besides SHP-1 and SHP-2, platelet endothelial cell adhesion molecule 1 binds the cytoplasmic signalling proteins SHIP and PLC-gamma 1 via their Src homology 2 domains. Using two phosphopeptides, NSDVQpY(663)TEVQV and DTETVpY(686)SEVRK, we demonstrate differential binding of SHP-1, SHP-2, SHIP and PLC-gamma 1. All four cytoplasmic signalling proteins directly associate with cellular platelet endothelial cell adhesion molecule 1, immunoprecipitated from pervanadate-stimulated THP-1 cells, These results suggest that overlapping immunoreceptor tyrosine-based inhibition motif/immunoreceptor tyrosine-based activation motif-like motifs within platelet endothelial cell adhesion molecule 1 mediate differential interactions between the Src homology 2 containing signalling proteins SHP-1, SHP-2, SHIP and PLC-gamma 1. (C) 1999 Federation of European Biochemical Societies.