Figure 2.

Molecular structure of CCN2 and its interactions with canonical FGFs and their receptors. Tetra-modular structure of CCN2 with a signal peptide for secretion (black triangle) and a hinge domain (wavy line between V and T) is illustrated at the middle of the top. I, V, T, and C represent insulin-like growth factor binding protein-like (IGFBP), von Willebrand factor type C repeat (VWC), thrombospondin 1 type 1 repeat (TSP1), and C-terminal cystine knot (CT) modules, respectively. Bi-directional arrows denote direct binding between the two. Out of four FGF receptors, FGFR1, -2 and -3 are all known to bind to CCN2.