Fig. 2

Schematic diagram of the domain structures of CCN-1 and LDL receptor showing their canonical interactions. Left) CCN-1 consist of insulin-like growth factor-binding protein (IGFBP), von Willebrand factor type C repeat (vWF-C), thrombospondin type I repeat (TSP), and a carboxyl-terminal cystine knot motif (CTCK) domain. The locations of identified interaction with cell receptors and soluble factors are shown in the diagram (modified from [228]). Right) The ligand-binding region of the LDL receptor is formed by several LDLrA domains in tandem, followed by 2 EGF-like domains. This region, also present in SCO-spondin, binds several molecules shown in the image and is characteristic and conserved in all members of the LDLr family (Modified from [103]). BMP Bone morphogenetic protein, CTCK Carboxyl-terminal cystine knot, EGF Epidermal growth factor, EMI Elastin microfibril interface domain, HBD Heparin-binding domain, HSPG Heparan sulfate proteoglycan, IGF insulin-like growth factor, IGFBP insulin-like growth factor-binding protein, LDLr Low density lipoprotein receptor, LRP LDLr-related protein, TGFβ Transforming growth factor β, TSR Thrombospondin repeat, TrkA Tyrosine kinase A, TSP Thrombospondin, VEGF Vascular endothelial growth factor, vWF von Willebrand factor, vWF-A,C and D von Willebrand factor domain type A,C and D