Connective tissue growth factor differentially binds to members of the cystine knot superfamily and potentiates platelet-derived growth factor-B signaling in rabbit corneal fibroblast cells

Figure 1 Determination of connective tissue growth factor binding to cystine knot motifs of vascular endothelial growth factor-A, platelet-derived growth factor-B, transforming growth factor-β1, and bone morphogenetic protein-4 in yeast two-hybrid LexA system. A: CTGF binding to cystine knot motifs of tested growth factors was assessed using growth assay on selective SD medium lacking leucine (lower panel); B: The liquid β-galactosidase assay was also carried out determining the binding strength of CTGF to cystine knot motifs of tested growth factors. The relative β-galactosidase activity was quantified in graph on the right. ^aP < 0.05; ^bP < 0.01. Values are the average -folds of activation over pB42-AD vector alone (arbitrarily set to 1) from three independent experiments performed in triplicate ± SD. CTGF: Connective tissue growth factor; VEGF: Vascular endothelial growth factor; BMP: Bone morphogenetic protein-4; TGF-β1: Transforming growth factor-β1; PDGF-B: Platelet-derived growth factor-B.