No Evidence for a Functional Role of Bi-Directional Notch Signaling during Angiogenesis
Figure 2
JAG1 is processed by gamma-secretase.
HUVEC were transduced with adenoviruses expressing GFP, full length JAG1. The intracellular JAG1 domain fused to Citrine, or DLL1 tagged with V5 at the carboxyterminus. (A) JAG1 was processed and the cleavage products have the predicted size of the transmembrane-intracellular domain fragment (TM-ICD) and the free intracellular domain (ICD). The membrane was blotted with JAG1 antibodies recognizing the carboxyterminal intracellular domain. (B) Treatment with VEGF or FGF2 did not significantly increase ligand cleavage compared to solvent as control. Inhibition of gamma-secretase activity with 25 µM DAPT prevented the formation of the intracellular domain and led to accumulation of the uncleaved TM-ICD fragment. (C) The predicted size of the DLL1 intracellular domain, tagged with V5, was detected in HUVEC lysates by Western blotting.