Netrins were first identified as neural guidance molecules, acting through receptors that are members of the DCC and UNC-5 family. All netrins share structural homology to the laminin N-terminal domains and the laminin epidermal growth factor-like domains of laminin short arms. Laminins use these domains to self-assemble into complex networks. Here we demonstrate that netrin-4 is a component of basement membranes and is integrated into the laminin polymer via interactions with the laminin gamma1 andgamma3 short arms. The binding is mediated through the laminin N-terminal domain of netrin-4. In contrast to netrin-4, other members of the netrin family do not bind to these laminin short arms. Moreover, a truncated form of netrin-4 completely inhibits laminin-111 self-assembly in vitro, and full-length netrin-4 can partially disrupt laminin self-interactions. When added to explant cultures, netrin-4 retards salivary gland branching morphogenesis.
Schneiders, F., Maertens, B., Böse, K., Li, Y., Brunken, W. J., Paulsson, M., Smyth, N., & Koch, M. (2007). Binding of netrin-4 to laminin short arms regulates basement membrane assembly. Journal of Biological Chemistry, 282(33), 23750-23758. https://doi.org/10.1074/jbc.M703137200