Caβ retains its ability to shift GV curves, but maximal conductances are reduced in channels bearing mutations of AID-exposed residues

Abstract

(A) Macroscopic currents from oocytes coexpressing Caβ with either Ca1.2 E462R or Ca1.2 K465N during the same stimulation protocol used in (shown at the top), with calibration bars corresponding to 20 ms and 200 nA. (B) GV curves in the presence (filled symbol) or absence (open symbol) of Caβ. (C) Plots of tail current amplitudes normalized by Q (I/Q) for Ca1.2 WT (▪), Ca1.2 E462R (•), and Ca1.2 K465N (▴). I/Q (mean ± SEM) versus voltage plots were fitted to the sum of two Boltzmann distributions. The maximal I/Q was 17.8 ± 2.5 nA/pC ( = 24) for Ca1.2 WT + Caβ, 7.4 ± 1.74 nA/pC ( = 11) for Ca1.2 K465N + Caβ, and 3.5 ± 0.8 nA/pC pC ( = 10) for Ca1.2 E462R + Caβ.<p><b>Copyright information:</b></p><p>Taken from "Mutations of Nonconserved Residues within the Calcium Channel α-interaction Domain Inhibit β-Subunit Potentiation"</p><p></p><p>The Journal of General Physiology 2008;132(3):383-395.</p><p>Published online Jan 2008</p><p>PMCID:PMC2518731.</p><p></p