Figure 5.
Response of native ITRPM7 to 2-APB. A and B, I–V relations in C363S- and WT CiVSP–expressing HEK cells immediately before (black) and in the presence of 100 μm 2-APB (red). The w/o trace in B refers to washout. C and D, corresponding time courses of ITRPM7 amplitude from the same cells as in A and B and 0.05% DMSO control. E, extent of current inhibition by 2-APB and 0.05% DMSO alone in C363S- and WT CiVSP–expressing cells. F, extent of current reduction in 100 μm 2-APB, 0.05% DMSO, and vehicle control in WT DrVSP–expressing cells. The fraction of unblocked current was obtained by dividing ITRPM7 amplitudes immediately before adding 2-APB or DMSO and after 72 (E) and 60 (F) voltage ramps in their presence. Y = 1 corresponds to no inhibition. *, p < 0.05; Student's two-sample t test. Internal free [Mg2+] was 400 nm, and the holding potential was 0 mV. n.s., not significant.