Deletion of the JM domain renders VEGFR-2 an unstable protein.
A, schematic of VEGFR-2 and JM domain-deleted VEGFR-2 (ΔJM/VEGFR-2). B, whole cell lysates (WCL) from PAE cells expressing VEGFR-2 alone, ΔJM/VEGFR-2 alone, or coexpressing with PDCL3 or cells treated with MG132 were blotted with anti-VEGFR-2 antibody, anti-c-myc antibody for PDCL3, and HSp70 for protein loading control. C, graph representative of three independent experiments. D, cell lysates from PAE cells expressing VEGFR-2, ΔJM/VEGFR-2 alone, or coexpressing PDCL3 were immunoprecipitated (IP) with anti-VEGFR-2 antibody and blotted with anti-c-myc antibody for PDCL3. D, whole cell lysates (WCL) from the same groups. E, the same membrane was reblotted with anti-VEGFR-2. PAE cells expressing VEGFR-2 or ΔJM/VEGFR-2 were subjected to cell surface biotinylation and blotted with streptavidin-horseradish peroxidase (SA-HRP) (top panel), anti-VEGFR-2 antibody, and anti-Hsp70. All the Western blot analyses shown are the representative of at least three independent experiments.