Cell adhesion molecule which is required for leukocyte transendothelial migration (TEM) under most inflammatory conditions (, ). Tyr-690 plays a critical role in TEM and is required for efficient trafficking of PECAM1 to and from the lateral border recycling compartment (LBRC) and is also essential for the LBRC membrane to be targeted around migrating leukocytes . Trans-homophilic interaction may play a role in endothelial cell-cell adhesion via cell junctions . Heterophilic interaction with CD177 plays a role in transendothelial migration of neutrophils . Homophilic ligation of PECAM1 prevents macrophage-mediated phagocytosis of neighboring viable leukocytes by transmitting a detachment signal . Promotes macrophage-mediated phagocytosis of apoptotic leukocytes by tethering them to the phagocytic cells; PECAM1-mediated detachment signal appears to be disabled in apoptotic leukocytes . Modulates bradykinin receptor BDKRB2 activation . Regulates bradykinin- and hyperosmotic shock-induced ERK1/2 activation in endothelial cells . Induces susceptibility to atherosclerosis (By similarity).
Does not protect against apoptosis.
Subcellular locations: Cell membrane
Cell surface expression on neutrophils is down-regulated upon fMLP or CXCL8/IL8-mediated stimulation.
Subcellular locations: Cell membrane, Membrane raft, Cell junction
Localizes to the lateral border recycling compartment (LBRC) and recycles from the LBRC to the junction in resting endothelial cells.
Subcellular locations: Cell junction
Localizes to the lateral border recycling compartment (LBRC) and recycles from the LBRC to the junction in resting endothelial cells.
Expressed on platelets and leukocytes and is primarily concentrated at the borders between endothelial cells (, ). Expressed in human umbilical vein endothelial cells (HUVECs) (at protein level) (, ). Expressed on neutrophils (at protein level) . Isoform Long predominates in all tissues examined . Isoform Delta12 is detected only in trachea . Isoform Delta14-15 is only detected in lung . Isoform Delta14 is detected in all tissues examined with the strongest expression in heart . Isoform Delta15 is expressed in brain, testis, ovary, cell surface of platelets, human umbilical vein endothelial cells (HUVECs), Jurkat T-cell leukemia, human erythroleukemia (HEL) and U-937 histiocytic lymphoma cell lines (at protein level) (, ).