Ca2+ microdomains near plasma membrane Ca2+ channels: impact on cell function.
In eukaryotic cells, a rise in cytoplasmic Ca(2+) can activate a plethora of responses that operate on time scales ranging from milliseconds to days. Inherent to the use of a promiscuous signal like Ca(2+) is the problem of specificity: how can Ca(2+) activate some responses but not others? We now know that the spatial profile of the Ca(2+) signal is important Ca(2+) does not simply rise uniformly throughout the cytoplasm upon stimulation but can reach very high levels locally, creating spatial gradients. The most fundamental local Ca(2+) signal is the Ca(2+) microdomain that develops rapidly near open plasmalemmal Ca(2+) channels like voltage-gated L-type (Cav1.2) and store-operated CRAC channels. Recent work has revealed that Ca(2+) microdomains arising from these channels are remarkably versatile in triggering a range of responses that differ enormously in both temporal and spatial profile. Here, I delineate basic features of Ca(2+) microdomains and then describe how these highly local signals are used by Ca(2+)-permeable channels to drive cellular responses.
Parekh
Anant B
AB
Department of Physiology, Anatomy and Genetics, Oxford University, Parks Road, Oxford OX1 3PT, UK. anant.parekh@dpag.ox.ac.uk
D000818:Animals; D001001:Anura; D015220:Calcium Channels / Q000378:metabolism*; D020013:Calcium Signaling; D002462:Cell Membrane / Q000378:metabolism*; D006801:Humans; D009474:Neurons / Q000502:physiology; D017434:Protein Structure, Tertiary
D015220:Calcium Channels