The Language of Calcium Signaling

Ca²⁺ signals are a core regulator of plant cell physiology and cellular responses to the environment. The channels, pumps, and carriers that underlie Ca²⁺ homeostasis provide the mechanistic basis for generation of Ca²⁺ signals by regulating movement of Ca²⁺ ions between subcellular compartments and between the cell and its extracellular environment. The information encoded within the Ca²⁺ transients is decoded and transmitted by a toolkit of Ca²⁺-binding proteins that regulate transcription via Ca²⁺-responsive promoter elements and that regulate protein phosphorylation. Ca²⁺-signaling networks have architectural structures comparable to scale-free networks and bow tie networks in computing, and these similarities help explain such properties of Ca²⁺-signaling networks as robustness, evolvability, and the ability to process multiple signals simultaneously.