Fig. 9. The ADAM22 variant 4 mutant lacking the ability to bind 14-3-3 proteins transports less efficiently to the cell surface. Cell surface biotinylation of D645 cells transfected with FLAG-tagged ADAM22 wild type, FLAG-tagged ADAM22 substitution mutant of the first and second 14-3-3 consensus binding motifs or FLAG-tagged ADAM22 C-terminal deletion mutant lacking both 14-3-3 binding sites and di-arginine retention motifs. Streptavidin-isolated ADAM22 proteins were detected with anti-FLAG antibody. Cell lysates were immunoblotted with anti-FLAG as control for protein expression.