FIGURE 5.

αArg²¹ and σ2Arg¹⁵ are not involved in Kir2.3 binding. The positively charged residues that interact with Asp or Glu in a canonical di-Leu motif are contributed by αArg²¹ and σ2Arg¹⁵ in AP-2. A, to determine whether these amino acids contribute to binding of the TDH motif in Kir2.3, hemicomplexes containing the mutations αR21S and σ2R15S were used in pulldown assays with GST-Kir2.3. Mutant hemicomplexes were competent for Kir2.3 binding but were unable to interact with Nef. IB, immunoblot. B, densitometric quantification and summary of the data from three separate experiments (mean ± S.E., p < 0.05).