Fig. 2.
Indole activates the wild-type TRPY1. In whole-vacuole recording mode (A, B) and in excised cytoplasmic-side-out patch mode (C); currents flowing into the cytoplasm are shown downward by convention. A. Ca2+ activation. Increasing [Ca2+] from 10-7 M to 10-5 M Ca2+ (arrow) activated an ensemble of the ~300-pS unitary conductances (in 150 mM KCl). B. Indole activation. Addition of indole in 1% DMSO to the final concentration of 2 mM indole activated the ensemble current as well. C. Unitary conductances were activated in an excised patch with 10-5 M Ca2+ (left segment). Activities subsided after perfusion of 10-7 M Ca2+. At this [Ca2+], the application of 120 mm Hg pressure failed to activate the channel (second segment). The same patch bathed with 1% DMSO control solution did not activate the channel (third segment), but the addition of 2 mM indole did (final segment).