Figure 2: Both PKD1L3 and TRPP3 line the pore.

(a) Amino-acid sequence alignment of the putative pore region of human (h) and mouse (m) TRPP3 and PKD1L3. Red: identical; green: conserved. Residues marked by arrows were critical for ion selectivity. (b–d) Representative I–V curves of acid-induced currents of WT PKD1L3/TRPP3 in a bath solution containing Na⁺, dimethylamine⁺, trimethylamine⁺ or Mg²⁺. The two curves in each panel were obtained from the same oocyte. (e–j) Bar graph showing the reversal potential of currents recorded from WT (grey bars) or mutant (red bars) PKD1L3/TRPP3 complexes (mutation indicated at the top of each panel) in a bath solution containing dimethylamine⁺, trimethylamine⁺ or Mg²⁺. All pairwise data were obtained from the same batch of oocytes and all pairwise comparisons are significantly different (P<0.05 as determined by unpaired two-tailed Student’s t-test), except the middle panel in j. Representative I–V curve for each condition is shown in Supplementary Fig. S2. Results are shown as mean and s.d. n=number of measurements.