FIG. 5.

“Gain-of-function” studies identify substrates for overexpressed ADAM9 with known roles in angiogenesis in cell-based assays. To identify potential substrates of ADAM9 that might be relevant for its function in pathological neovascularization, AP-tagged membrane proteins with known roles in angiogenesis were overexpressed in Cos-7 cells together with empty vector (−), wild-type mouse ADAM9 (9), or the catalytically inactive ADAM9E>A mutant (9EA). The graphs depict the relative AP activity in the supernatant of transfected cells, with the AP activity in cells transfected with a candidate substrate and empty vector set to 1. Each graph is representative of data from at least three separate experiments with two wells per experiment. These results show that overexpressed ADAM9 increases levels of shedding of Tie-2, Flk1 (VEGFR2), VE-cadherin, EphB4, CD40, and VCAM-1 but not of EphrinB2, ICAM, or E-selectin.