Figure 6.

K121 regulates CK2 coassembled with SK2 channels. a, Amino acid sequence (109–134) of the positively charged cluster in the SK2 N-terminal domain that includes the identified CK2 α binding site (RRALF; underlined). Asterisk indicates K121; the mutated lysine residues are in bold type. b, SK2 current deactivation for control SK2 (black traces) and after application of 5 mm MgATP (gray traces) for wild-type, SK2 K121A, and SK2 5KtoA channels. Calibration, 50 ms. c, Average deactivation time constants derived from single exponential fits for SK2, SK2 K121A, and SK2 5KtoA before and after 5 mm ATP application.