Calcium signaling

Calcium signaling is the use of calcium ions (Ca) to communicate and drive intracellular processes, often as a step in signal transduction. Ca is important for a wide variety of cellular signaling pathways. Once Ca enters the cytosol of the cytoplasm it exerts allosteric regulatory effects on many enzymes and proteins. Ca signaling can activate certain ion channels for short term changes (like changes to electrochemical gradients) in the cell. For longer-term changes (like changes in gene transcription), Ca can act as a second messenger through indirect signal transduction pathways, such as in G protein-coupled receptor pathways. Calcium signaling plays a role in muscle contraction, fertilization, cell growth, synaptic plasticity and apoptosis.