Calmodulin Methylation: Another Layer of Regulation in Calcium Signaling

摘要

Similar to tuning your radio to play one station out of all of the others on the airwaves, calcium binding proteins transduce calcium signatures into specific downstream responses. The expression and subcellular localization of calcium (Ca2+) binding proteins are developmentally and spatially regulated, creating the tuner that allows each subcellular compartment to receive locally generated Ca2+ signals. In radios, tuning to a station allows you hear its broadcast; in plants, transducing Ca2+ signals influences biotic and abiotic stress responses, as well as normal growth and development. Calmodulin (CaM) serves as the main transducer of Ca2+ signals in eukaryotes, although plants have evolved additional Ca2+ binding proteins (reviewed in Perochon et al., 2011). Upon binding Ca2+, CaM interacts with a range of proteins that regulate specific Ca2+-responsive processes. It has long been known that posttranslational trimethylation of CaM can affect its function (Roberts et al., 1986), but this aspect of Ca2+-CaM signaling has generally been overlooked. New work from Banerjee et al. (pages 4493?511) demonstrates that trimethylation plays a role in several CaM-dependent processes.