Figure 7.

Q511H in Ca_v2.1 and Q767H in Ca_V3.1 decrease the number of functional channels. A, top, representative current traces from WT (left) or Q511H mutant (right) Ca_v2.1 channels showing I_gating evoked by a 20-ms step depolarization from −80 mV to +70 mV and I_tail upon repolarization to −80 mV. Insets show I_gating on expanded time scale. Bottom left, average maximal gating charge (Q_max) for WT (n = 10 cells) and Q511H mutant Ca_v2.1 channels (n = 8 cells); p value was determined by t test. Bottom right, I_tail for each cell is plotted against Q_max. The fit by linear regression and coefficient of determination (r²) are shown for WT and mutant channels. Results are from four independent experiments. Error bars represent S.E. B, same as in A except for WT (n = 11 cells) and Q767H mutant Ca_V3.1 channels (n = 11 cells). Results are from four independent experiments.