Modulation of gating currents of the Ca(v)3.1 calcium channel by alpha 2 delta 2 and gamma 5 subunits.

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Citation

Lacinova L, Klugbauer N

Modulation of gating currents of the Ca(v)3.1 calcium channel by alpha 2 delta 2 and gamma 5 subunits.

Arch Biochem Biophys. 2004 May 15;425(2):207-13.

PubMed ID
15111129 [ View in PubMed
]
Abstract

Modulatory effects of auxiliary alpha(2)delta(2) and gamma(5) subunits on intramembrane charge movement originating from the expressed Ca(v)3.1 calcium channel were investigated. Inward current was blocked by 1mM La(3+). Voltage dependences of Q(on) and Q(off), kinetics of ON- and OFF-charge movement, and I(max)/Q(max) ratio were measured in the absence and the presence of an auxiliary subunit. The alpha(2)delta(2) subunit accelerated significantly both ON- and OFF-charge movement. I(max)/Q(max) ratio and Q(on)-V, Q(off)-V relations were not affected. Coexpression of the alpha(2)delta(2) subunit may accelerate channel transitions between individual closed states, but not the transition from the last closed channel state into an open state. Coexpression of the gamma(5) subunit accelerated the decay of the ON-charge transient and enhanced I(max)/Q(max) ratio. These effects suggest improvement of the coupling between the charge movement and the channel opening due to facilitation of transitions between individual closed states and the transition between the last closed state and an open state.

DrugBank Data that Cites this Article

Polypeptides
NameUniProt ID
Voltage-dependent calcium channel subunit alpha-2/delta-2Q9NY47Details