Figure 11.

Ectopically expressed TspanC8 tetraspanins compete with endogenous Tspan5 for the association with ADAM10. A, flow cytometry analysis of U2OS cells stably expressing GFP-tagged Tspan5, Tspan14, Tspan15, or Tspan33 and stained or not with mAbs to ADAM10, CD81, or four anti-Tspan5 mAb. Note the increase in TS5-1r binding proportionally to the GFP signal and the slight decrease of the binding of TS5-2 and TS5-3. B, U2OS cells stably expressing or not GFP-tagged Tspan14, Tspan15, or Tspan33 were lysed in digitonin before immunoprecipitations (IP) with the anti-ADAM10 mAb 11G2 or the anti-Tspan5 mAbs TS5-2 and TS5-1r. The presence of Tspan5 and ADAM10 in the immunoprecipitates was visualized by immunoblotting using biotin-labeled TS5-2 and 11G2 mAbs. The band corresponding to the proform (p.) of ADAM10 is indicated. All experiments in this figure have been done three times with similar outcomes.