VAP-1/SSAO–dependent induction of selectin proteins in primary human endothelial cells. (A) HDMECs transfected with wild-type (VAP-1) or an enzymatically inactive mutant of VAP-1 (VAP-1 Y471F) were stained for cell-surface E-selectin and analyzed using FACS. neg co indicates negative control. (B) E-selectin was immunoprecipitated (IP) from the cell-culture supernatant of the transfected cells after a 45-minute pulse and chase of the indicated length. (C) P-selectin was immunoprecipitated from the cell lysate and from the cell-culture supernatant after a 45-minute pulse and chase of the indicated time. Arrows on the right point to the specific immunoprecipitates, and molecular weight markers in kDa are shown on the left.