Calcium channel diversity: multiple roles of calcium channel subunits.
Until recently we held the simple view that voltage-gated calcium channels consisted of an alpha1 subunit, usually associated with auxiliary beta subunits and alpha(2)delta subunits and that skeletal muscle calcium channels were also associated with a gamma subunit. However, as discussed here, there is now evidence that the auxiliary subunits may also perform other roles unrelated to voltage-gated calcium entry. In the past students were taught the simplistic view that second messenger signaling to voltage-gated calcium channels involved mainly phosphorylation of L-type calcium channels, Ca(2+)-dependent inactivation via calmodulin, and direct G-protein-mediated inhibition of the neuronal N and P/Q channels. However, it is now clear that there are many other means of modulating calcium channel activity, including receptor-mediated internalization, proteolytic cleavage, phosphorylation of beta subunits, and interaction of calcium channels with other proteins, including enzymes masquerading as scaffold proteins.
Dolphin
Annette C
AC
Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK. a.dolphin@ucl.ac.uk
D000818:Animals; D001921:Brain / Q000378:metabolism; D015220:Calcium Channels / Q000235:genetics / Q000378:metabolism*; D020746:Calcium Channels, L-Type / Q000235:genetics / Q000378:metabolism; D008959:Models, Neurological; D009474:Neurons / Q000378:metabolism
D015220:Calcium Channels; D020746:Calcium Channels, L-Type; C419385:L-type calcium channel alpha(1C)