Fig. 4.

Depletion of clathrin heavy chain disrupts VEGF-A isoform-specific programing of Akt and ERK1/2, but not p38 MAPK activation. (A) Endothelial cells were subjected to scrambled (Scr) or clathrin heavy chain (CHC17)-specific siRNA duplexes, were stimulated with VEGF-A₁₆₅ (165), VEGF-A₁₂₁ (121) or VEGF-A₁₄₅ (145; 1.25 nM) for 0 or 15 min prior to cell lysis and processing for immunoblot analysis of signal transduction. (B-E) Quantification of VEGFR2-pY1175 (B) and VEGFR2-pY1214 (C), Akt-pS473 (D) and ERK1/2-pT202/pY204 (E) levels upon VEGF-A isoform stimulation. (F) Endothelial cells were subjected to scrambled (Scr) or clathrin heavy chain (CHC17)-specific siRNA duplexes, were stimulated with either VEGF-A₁₆₅, VEGF-A₁₂₁ or VEGF-A₁₄₅ (1.25 nM) for 15 min prior to cell lysis and processing for immunoblotting. (G) Quantification of p38 MAPK-pT180/pY182 levels upon VEGF-A isoform stimulation. Error bars indicate ±s.e.m. (n=3). *P<0.05, **P<0.01, ***P<0.001, ****P<0.0001.