Single-molecule study of VEGFR-2 spatiotemporal organization and activation on the surface of live endothelial cells

The dynamic organization of cell surface receptors plays an important role in signaling. Here we investigated the spatiotemporal organization of VEGF receptor-2 (VEGFR-2), a critical pro-angiogenic receptor tyrosine kinase in live, microvascular endothelial cells. Our study strategy combined live-cell single-molecule imaging of endogenous VEGFR-2 with computational image analysis and multiscale data analysis. We found that VEGFR-2, even in its basal, unstimulated state, possesses diffusion heterogeneity, with a mobile subpopulation and a subpopulation of restricted mobility, and assembly state heterogeneity, where receptors can be organized as monomeric or non-monomeric.