A Cellular Striptease Act

Proteins on the cell surface can be cleaved by proteolytic enzymes. In the Perspective, Werb and Yan outline the many purposes of these cleavage events-to provide ligand for binding to receptors (as shown in the report by Peschon et al. on p. 1281), to eliminate ligand on receptors and to increase or decrease cell-cell interactions. Such proteolysis can be regulated and is turning out to be widely used by the cell.