Platelet endothelial cell adhesion molecule‐1 is a major SH‐PTP2 binding protein in vascular endothelial cells

Platelet endothelial cell adhesion molecule-1 (PECAM-1, CD31) is rapidly tyrosine phosphorylated in mechanically stimulated vascular endothelial cells (ECs). A 65-kDa protein from ECs specifically bound to the c-Src phosphorylated PECAM-1 cytoplasmic domain and was identified as a protein tyrosine phosphatase SH-PTP2 (SHP2, Syp). PECAM-1 was coimmunoprecipitated by anti-SH-PTP2 from EC extracts as a major binding protein, and the level of association increased when PECAM-1 was tyrosine phosphorylated. This association was mediated by SH2 domains of SH-PTP2. A rapid translocation of SH-PTP2 into cell-cell adhesion sites, where PECAM-1 was localized, occurred in mechanically stimulated cells. Our results suggest that PECAM-1 is a component of a mechanosensing machinery acting upstream of SH-PTP2.