Figure 3.

Overexpression of AKAP or CaM does not augment KCNQ2/3 current modulation. (A) Simultaneous recording of calcium responses (Fura-4F; top) and KCNQ2/3 tail currents (bottom) in a cell expressing M₁R, KCNQ2/3, and AKAP79. Responses were elicited by 10 µM Oxo-M, by 100 µM UTP (acting on endogenous P2Y₂Rs), and by 10 µM of the DAG analogue OAG. (B) Summary of experiments as in A from cells without and with AKAP79 transfection. Responses to 100 µM UTP were recorded in the perforated-patch configuration (without and with AKAP79, n = 11 and 6). Responses to Oxo-M (n = 9 and 5 for 10 nM; n = 23 and 15 for 10 µM) and 10 µM OAG (n = 6 and 27) were not significantly different for whole-cell and perforated-patch configuration and therefore were pooled. Two-way ANOVA showed no significant effect of AKAP79 expression. (C) Simultaneous recording of calcium responses (Fura-4F; top) and KCNQ2/3 tail currents (bottom) from a cell expressing M₁R, KCNQ2/3, and CaM-YFP. Responses were elicited by 10 µM Oxo-M and 100 µM UTP, or by 5 µM ionomycin (extracellular calcium, 2 mM). (D) Summary of experiments as in C from cells without and with CaM-YFP expression. Responses to UTP were recorded in the perforated-patch configuration (n = 11 and 5). Responses to Oxo-M (n = 23 and 13) and ionomycin (n = 7 and 10) were not significantly different for whole-cell and perforated-patch configuration and therefore were pooled. Two-way ANOVA showed no significant effect of CaM expression.