Functions of selectins.

The selectins are cell surface lectins that have evolved to mediate the adhesion of white blood cells to endothelial cells and platelets under flow. They recognize fucosylated, sialylated and in some cases sulfated ligands expressed on scaffold glycoproteins serving as functional counter-receptors. Selectins are regulated at the transcriptional level, through proteolytic processing, through cellular sorting, and through regulated expression of glycosyl-transferases responsible for the formation of functional ligands. The selectins are physiologically important in inflammation, lymphocyte homing, immunological responses, and homing of bone marrow stem cells. They play a role in atherosclerosis, ischemia-reperfusion injury, inflammatory diseases, and metastatic spreading of some cancers.