Issues

Cover picture: Point mutations that cause the CNGA1 channel to become voltage-gated are clustered around the ion selectivity filter. (Top and Middle) Alanine substitutions at red- and yellow-colored positions produce channels with strongly and modestly voltage-gated currents, respectively, whereas those at blue-colored positions yield unmeasurable currents. The remaining mutations produce non-voltage–gated currents. (Bottom) Degree of voltage gating of mutant channels, expressed as the ratio of current at two holding potentials (I₂₀₀ /I₋₂₀₀ or I₂₀₀ /I₁₀) (see article by Martínez-François et al., 151–164).