Figure 8.

hERG channels are sensitive to M₁R activation but not to activation of Dr-VSP or pseudojanin. (A) Currents in hERG channels coexpressed with Dr-VSP. Black indicates before activation of Dr-VSP, and red indicates directly after activation of Dr-VSP. Arrows indicate points at which peak and tail current amplitudes were measured. (B) Same as in A but with additional coexpression of KCNE2 and modified pulse protocol. (C) Currents in hERG channels coexpressed with KCNE2 and M₁R. Black indicates before application of 10 µM Oxo-M, and red indicates after application of Oxo-M. Pulse protocol as in B. (D) Time course of current amplitudes at 10 mV and Fura-4F ratio of cell in C. (E) Currents in a cell expressing hERG, KCNE2, pseudojanin-YFP, and LDR-CFP. Currents are shown at the beginning of the recordings (black), directly before application of rapamycin (50 s after start of experiment; red), and at the end of rapamycin application (150 s after start of experiment; blue). Pulse protocol as in B. (F) Time course of current amplitudes of tail currents at −40 mV of the experiment in E (black) and FRET ratio between pseudojanin (PJ)-YFP and the anchor LDR-CFP (red).