Elementary and global aspects of calcium signalling.
Calcium is a ubiquitous second messenger used to regulate a wide range of cellular processes. This role in signalling has to be conducted against the rigid homeostatic mechanisms that ensure that the resting level of Ca2+ is kept low (i.e. between 20 and 100 nmol l-1) in order to avoid the cytotoxic effects of a prolonged elevation of [Ca2+]. Cells have evolved a sophisticated signalling system based on the generation of brief pulses of Ca2+ which enables this ion to be used as a messenger, thus avoiding its toxic effects. Such Ca2+ spikes usually result from the coordinated release of Ca2+ from internal stores using either inositol 1,4,5-trisphosphate or ryanodine receptors. Using Ca2+ imaging techniques, the opening of individual channels has now been visualized and models have been proposed to explain how these elementary events are coordinated to generate the global Ca2+ signals that regulate cellular activity.
Berridge
M J
MJ
Babraham Institute Laboratory of Molecular Signalling, Cambridge, UK. mjb38@cus.cam.ac.uk
D000818:Animals; D002118:Calcium / Q000502:physiology*; D015220:Calcium Channels / Q000378:metabolism; D020746:Calcium Channels, L-Type; D002462:Cell Membrane / Q000378:metabolism; D006706:Homeostasis / Q000502:physiology; D015544:Inositol 1,4,5-Trisphosphate / Q000502:physiology; D007424:Intracellular Fluid / Q000378:metabolism; D008954:Models, Biological; D009124:Muscle Proteins / Q000378:metabolism; D009928:Organ Specificity; D010507:Periodicity; D019837:Ryanodine Receptor Calcium Release Channel; D015290:Second Messenger Systems / Q000502:physiology*
D015220:Calcium Channels; D020746:Calcium Channels, L-Type; D009124:Muscle Proteins; D019837:Ryanodine Receptor Calcium Release Channel; D015544:Inositol 1,4,5-Trisphosphate; D002118:Calcium