Role of putative voltage-sensor countercharge D4 in regulating gating properties of Ca_V1.2 and Ca_V1.3 calcium channels

Voltage-dependent calcium channels (CaV) activate over a wide range of membrane potentials, and the voltage-dependence of activation of specific channel isoforms is exquisitely tuned to their diverse functions in excitable cells. Alternative splicing further adds to the stunning diversity of gating properties. For example, developmentally regulated insertion of an alternatively spliced exon 29 in the fourth voltage-sensing domain (VSD IV) of...