Title: Unified mechanisms of Ca2+ regulation across the Ca2+ channel family.

Authors: Haoya Liang, Carla D DeMaria, Michael G Erickson, Masayuki X Mori, Badr A Alseikhan, David T Yue

Journal, date & volume: Neuron, 2003 Sep 11 , 39, 951-60

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/12971895

Abstract
L-type (CaV1.2) and P/Q-type (CaV2.1) calcium channels possess lobe-specific CaM regulation, where Ca2+ binding to one or the other lobe of CaM triggers regulation, even with inverted polarity of modulation between channels. Other major members of the CaV1-2 channel family, R-type (CaV2.3) and N-type (CaV2.2), have appeared to lack such CaM regulation. We report here that R- and N-type channels undergo Ca(2+)-dependent inactivation, which is mediated by the CaM N-terminal lobe and present only with mild Ca2+ buffering (0.5 mM EGTA) characteristic of many neurons. These features, together with the CaM regulatory profiles of L- and P/Q-type channels, are consistent with a simplifying principle for CaM signal detection in CaV1-2 channels-independent of channel context, the N- and C-terminal lobes of CaM appear invariably specialized for decoding local versus global Ca2+ activity, respectively.