A PECAM-1 a mechanoresponsive molecule?

Endothelial cells are capable of responding to fluid shear stress, but the molecular mechanism for this biological response remains largely unknown. Our studies indicate that the cell-cell adhesion site is a possible site of flow sensing, PECAM-1, a cell adhesion molecule localized to the interendothelial cell adhesion site, is tyrosine-phosphorylated when endothelial cells are exposed to physiological levels of fluid shear stress. This PECAM-1 phosphorylation initiates a signaling cascade leading to ERK activation. Here we review what is known about PECAM-1 tyrosine phosphorylation and suggest a possible role of PECAM-1 in mechanosensing by endothelial cells.