Activity-dependent regulation of T-type calcium channels by submembrane calcium ions.

ABSTRACT: Voltage-gated Ca2+ channels are involved in numerous physiological functions and various mechanisms finely tune their activity, including the Ca2+ ion itself. This is well exemplified by the Ca2+-dependent inactivation of L-type Ca2+ channels, whose alteration contributes to the dramatic disease Timothy Syndrome. For T-type Ca2+ channels, a long-held view is that they are not regulated by intracellular Ca2+. Here we challenge this notion by using dedicated electrophysiological protocols on both native and expressed T-type Ca2+ channels. We demonstrate that a rise in submembrane Ca2+ induces a large decrease in T-type current amplitude due to a hyperpolarizing shift in the steady-state inactivation. Activation of most representative Ca2+-permeable ionotropic receptors similarly regulate T-t

SUBMITTER: Cazade M 

PROVIDER: S-EPMC5308894 | biostudies-literature | 2017 Jan

REPOSITORIES: biostudies-literature