calcium channel subunit alpha-1I

Voltage-sensitive calcium channels (VSCC) mediate the entry of calcium ions into excitable cells and are also involved in a variety of calcium-dependent processes, including muscle contraction, hormone or neurotransmitter release, gene expression, cell motility, cell division and cell death. T-type channels serve pacemaking functions in both central neurons and cardiac nodal cells and support calcium signaling in secretory cells and vascular smooth muscle. They may also be involved in the modulation of firing patterns of neurons which is important for information processing as well as in cell growth processes. Using co-transfection techniques we investigated the functional effects of each of the gamma subunits on the biophysics of the T-type VSCC encoded by the alpha(1I) subunit. This revealed a substantially slowed rate of deactivation in the presence of gamma(2). In contrast, there was no significant corresponding effect of either gamma(3) or gamma(4) on alpha(1I) subunit-mediated currents.(2)