Cell surface proteolysis has emerged as an important mechanism for the generation of
biologically active proteins that mediate a diverse range of cellular functions. The proteolytic
activities of membrane-anchored proteins, such as ADAMs1 (1) and MT-MMPs (2), are
thought to play central roles in cell surface-activating events. In contrast, most of the
members of the serine protease family, one of the oldest characterized and largest
multigene proteolytic families, are either secreted enzymes or sequestered in cytoplasmic …