Figure 3.

PP2A is coassembled with SK2 channels. a, Amino acid sequence comparison of PP2A binding sites on SV40 small T-antigen, CK2α, and SK2 (467–476). Mutated residues are underlined, and the position of the truncation, R471, is indicated. b, Top, Anti-His Western blot of proteins eluted from GST pull-down experiments with His-tagged PP2A PR65 as prey with the following baits: GST, SK2 396-end containing the mutation EQRK to AQAA, and SK2 396-end. Bottom, Coomassie blue-stained gel showing the input GST-fusion bait proteins. c, Average deactivation time constants derived from single exponential fits for control SK2, SK2 coexpressed with the dominant negative PP2A (PR65 K416E), the SK2 EQRK to AQAA triple mutant, SK2 coexpressed with CaM T80D, and the SK2 truncation at position 471.