POSTTRANSLATIONAL MODIFICATIONS OF BETA-SUBUNITS OF VOLTAGE-DEPENDENTCALCIUM CHANNELS

Different post-translational modifications of Ca channel beta subunits have been identified. Recent studies have characterized the palmitoyl ation of the Ca channel beta(2a) subunit, as well as one effect of thi s modification on channel function. The potential importance of palmit oylation on other channel properties is discussed. Other studies have addressed the role of phosphorylation of beta subunits in the regulati on of voltage-dependent Ca channels. Phosphorylation of beta subunits by second messenger-activated protein kinases, as well as by unidentif ied protein kinases, may affect interactions between channel subunits and other aspects of channel function. The differential modification o f Ca channel beta subunit isoforms by post-translational events likely results in diversely regulated channels with unique properties.