Decalmodulation of Cav1 channels by CaBPs.

Ca(2+)-dependent inactivation (CDI) is a negative feedback regulation of voltage-gated Cav1 and Cav2 channels that is mediated by the Ca(2+) sensing protein, calmodulin (CaM), binding to the pore-forming Cav α1 subunit. David Yue and his colleagues made seminal contributions to our understanding of this process, as well as factors that regulate CDI. Important in this regard are members of a family of Ca(2+) binding proteins (CaBPs) that are related to calmodulin. CaBPs are expressed mainly in neural tissues and can antagonize CaM-dependent CDI for Cav1 L-type channels. This review will focus on the roles of CaBPs as Cav1-interacting proteins, and the significance of these interactions for vision, hearing, and neuronal Ca(2+) signaling events.