Reports

Netrins, acting as both attractants and repellents, regulate neuronal mi-gration, axon guidance and synaptogenesis (1–4). In non-neural tissues, netrins have a variety of functions, including promoting cell adhesion and invasion, leukocyte migration, angiogenesis, and cell survival (5). Netrins contain an N-terminal laminin domain (LN, a.k.a. domain VI), followed by three cysteine-rich laminin-type epidermal growth factor (EGF) –like modules (LE1, LE2, and LE3, a.k.a. domain V), and a small positively charged C-terminal domain (LC). In mammals, the secreted Netrins-1,-3 and-4 are only distantly related to the GPI-anchored G netrins (6, 7). Netrin actions are mediated by distinct receptors (4). DCC mediates attractive responses to Netrin-1, whereas Unc5 proteins, alone or with DCC, are required for its repulsive effects (4, 8). The ectodomain of DCC is composed of four immunoglobulin-like (Ig) domains and six fibronectin type III (FNIII) domains. The DCC FNIII repeats mediat