Slc7a5 promotes an interaction between Kv1.2 and Kvβ. Combinations (as indicated in Fig. 1 A) of Kv1.2, Slc7a5, Kvβ, and GFP were expressed in HEK293 cells. Co-IP showing that the interaction between Kv1.2 and Kvβ is enhanced in the presence of Slc7a5. GAPDH was used as a negative control. IgG is used as the loading control. WB, Western blotting; IB, immunoblotting. Consistent results were obtained from four independent co-IP experiments (Fig. S2).