Reelin is an extracellular matrix protein that is thought to regulate neuronal migration in the developing mammalian brain through interactions with various cell surface receptors. Quattrocchi et al. show that the primary structure of human Reelin is similar to that of serine proteases and demonstrate that purified Reelin is capable of degrading fibronectin, laminin, and collagen in vitro in a diisopropylfluorophosphate-sensitive fashion. Furthermore, this activity could be partially inhibited by a Reelin antibody that is known to block Reelin function in vivo, and overexpression of Reelin in human embryonic kidney cells caused a decrease in cell adhesion to fibronectin. The authors propose that Reelin may directly modulate cell attachment through proteolysis. — LDC
J. Biol. Chem.277, 303 (2002).