Figure 3.

VEGFR1 carries Vav1 to lysosomes for degradation. (A) HUVECs were immunostained for Cathepsin D, Vav1 and VEGFR1, and analyzed by confocal microscopy. (B) HeLa cells were co-transfected with expression vectors for Vav1 and wild type VEGFR1 or the Vav1 binding domain deleted construct, ΔYKEP. Cells were stained with Lamp2 (red) and Vav1 (green). (C) HUVECs were stimulated with either PlGF or VEGF-E at 50 ng/mL for 5 h, followed by staining with antibodies for Vav1 (green) and imaged under confocal microscopy. (D) HUVECs were stimulated with either PlGF or VEGF-E at 50 ng/mL for 5 h, followed by Western blot to detect VEGFR1 levels. (E) HUVECs were infected with lentiviral vectors carrying scrambled or VEGFR1 shRNAs and cultured in either 20% O₂ or 1% O₂ incubators. Cell lysates were analyzed by Western blot for Vav1 and VEGFR1. (F) HUVECs were transfected with expression vectors for Vav1 with either VEGFR1 or ΔYKEP VEGFR1. The levels of Vav1 and VEGFR1 were assessed by Western blot. Mean ± SD, ** p < 0.01. The whole western blot images please find in Figure S2.