Fig. 5

KAI1 binds VEGF-A and PDGF-BB directly, resulting in inhibition of VEGFR2 and PDGFRβ signaling. a–c Protein–protein interactions between rhKAI1, rhVEGF-A, rhPDGF-BB and rhFGF2 observed using surface plasmon resonance. A shift in nm indicates the binding of two proteins. d Top, VEGFR2 phosphorylation levels in HUVECs, in response to rhVEGF-A and rhKAI1 treatment. Bottom, PDGFRβ phosphorylation level in human brain vascular PCs (HBVPs), in response to rhPDGF-BB and rhKAI1 treatment. e Quantification of the obtained results (ns not significant, *p < 0.01, **p < 0.05, ***p < 0.001, Means ± SEM, 3 technical replicates). f Left, Bimolecular fluorescent complementation assays using Duolink visualizes the interaction of Kai1-Vegfa and Kai1-Pdgfbb in living cells. Right, quantification of the obtained results (*p < 0.01, **p < 0.05, Means ± SEM, 3 technical replicates). Scale bar, 50 μm. g After palmitoylation inhibition in 293 T cells, protein–protein interactions between KAI1-rhVEGF-A (top) and KAI1-rhPDGF-BB (bottom) observed using the immunoprecipitation (IP) assay