Talin binding to the β₃ tail inhibits the αβ TMD-tail interaction. (A) α_IIb^TM-TAP and Tac-β₃^TM were cotransfected with THD or THD(W359A) mutant into CHO cells, and their interaction was analyzed, as described in Figure 1C. Ratio of the amount of Tac-β₃^TM bound to α_IIb^TM-TAP in presence of wild-type THD to that in the presence of THD W359A is shown as a bar graph. The data are the mean ± SE of 4 experiments. (B) α_IIb^TM-TAP and THD were cotransfected with Tac-β₃^TM or Tac-β₃^TM(Y747A) mutant into CHO cells and their interaction was analyzed, as described in panel A. The data are mean ± SE of 3 experiments.