The Language of Calcium Signaling

Abstract

Ca(2+) signals are a core regulator of plant cell physiology and cellular responses to the environment. The channels, pumps, and carriers that underlie Ca(2+) homeostasis provide the mechanistic basis for generation of Ca(2+) signals by regulating movement of Ca(2+) ions between subcellular compartments and between the cell and its extracellular environment. The information encoded within the Ca(2+) transients is decoded and transmitted by a toolkit of Ca(2+)-binding proteins that regulate transcription via Ca(2+)-responsive promoter elements and that regulate protein phosphorylation. Ca(2+)-signaling networks have architectural structures comparable to scale-free networks and bow tie networks in computing, and these similarities help explain such properties of Ca(2+)-signaling networks as robustness, evolvability, and the ability to process multiple signals simultaneously.

Intracellular localization and physiological function of a rice Ca2+-permeable channel OsTPC1

“…1,2 Though electrophysiological studies have revealed several types of Ca 2+ -permeable channels localized at the plasma membrane (PM) and vacuolar membrane (VM) in many plant species, 3 their molecular identity are still largely unknown. Homologs of the major voltage-dependent Ca 2+ channels (VDCCs) are not found in plants.…”

Tonoplast calcium sensors CBL2 and CBL3 control plant growth and ion homeostasis through regulating V-ATPase activity in Arabidopsis

“…The Ca 2+ -dependent signaling pathways participate in many aspects of plant development and environmental responses [1][2][3]. It is generally believed that stimulus-specific calcium signals are encoded by temporally and spatially defined patterns of Ca 2+ fluctuations that result from concerted action of Ca 2+ transporters [4][5].…”

“…In response to low-K + status, CIPK23 is activated and recruited to the plasma membrane by Ca 2+ sensors CBL1 and CBL9, and the CBL-CIPK23 complexes activate the shaker-like K + channel AKT1 for optimal K + uptake under limiting K + supply conditions [21][22][23]. Apart from controlling K + transport in roots, the CBL1-CIPK23 and CBL9-CIPK23 complexes also regulate the dual-affinity nitrate (NO 3 − ) transporter CHL1 by phosphorylation that serves as a molecular switch between low-and high-affinity NO 3 − transport modes [24]. In addition to their central regulation of ion fluxes in plant cells, CBLs play other roles in various abiotic stress adaptations.…”

Plant Stress Surveillance Monitored by ABA and Disease Signaling Interactions

“…By changing amplitude, duration, and frequency of Ca 2+ transients accordingly to environmental and developmental stimuli, plant cells interpret the source of input signals and then produce proper responses (Dodd et al, 2010;Sanders et al, 2002). Considering various responses controlled by Ca 2+ signals, plant genome is expected to encode diverse Ca 2+ sensors and mechanisms to transmit the general secondary signals to specific target components.…”