(A, B) Effects of Zn2+ and Cd2+ on PKD2-L1 currents. Top, Exemplar PKD2-L1 currents activated by voltage ramps at the indicated [Zn2+]. Bottom, Corresponding time courses of the Zn2+ block of the Wt and D525N PKD2-L1 channels. The internal buffer was 15 mM BAPTA and 5 mM EGTA, which prevented Ca2+ accumulation and inactivation of the PKD2-L1 currents. (B) Divalent metal concentration-dependent block of the Wt, D523N and D525N channels (Error ± SEM, N = 4–6 cells). (C–E) Effects of trivalent metal block. Left, Exemplar PKD2-L1 currents activated by voltage ramps in the presence of La3+. Right, Corresponding time courses of the La3+ block of the indicated PKD2-L1 channels. (D) Concentration-dependent block of PKD2-L1 and D525N channels by trivalent ions, and (E) potentiation of the D523N filter mutant channel (Error ± SEM, N = 4–5 cells).