C-terminal Alternative Splicing Modulates Single-Channel Gating of Cav1.3 L-Type Calcium Channel

Abstract

We have recently discovered a novel mechanism of channel modulation in CaV1.3 channels enabling cells to tightly control gating by C-terminal alternative splicing. The absence of a C-terminal modulatory motif (CTM) within a short splice form facilitates CaV1.3 channel activation at lower voltages and induces pronounced Ca2+ dependent-inactivation (CDI) (Singh et al., JBC 2008). Intriguingly, whole-cell measurements revealed a significant difference in current density between long and short channels for both Ba2+ and Ca2+ currents (IBa and ICa) while membrane expression of the pore-forming subunit was unchanged suggesting additional differences of unitary current properties.