Ca2+ channel regulation by a conserved β subunit domain

M De Waard, M Pragnell, KP Campbell - Neuron, 1994 - cell.com
M De Waard, M Pragnell, KP Campbell
Neuron, 1994cell.com
The j3 subunit is a cytoplasmic component that normalizes the current amplitude, kinetics,
and voltage dependence of voltage-gated Caz+ channels. Here, we identify a 30 amino acid
domain of the jl subunit that is sufficient to induce a stimulation and shift in the voltage
dependence of activation of the Ca*+ channel currents. This domain is located at the amino
terminus of the second region of high conservation among all g subunit gene products.
Single point mutations within this region on the gIb subunit modified or abolished the …
Summary
The j3 subunit is a cytoplasmic component that normalizes the current amplitude, kinetics, and voltage dependence of voltage-gated Caz+ channels. Here, we identify a 30 amino acid domain of the jl subunit that is sufficient to induce a stimulation and shift in the voltage dependence of activation of the Ca*+ channel currents. This domain is located at the amino terminus of the second region of high conservation among all g subunit gene products. Single point mutations within this region on the gIb subunit modified or abolished the stimulation of Caz+ channel currents and the binding of the j? subunit to the ulA subunit. The binding of this domain is also required for theobserved changes in kinetics and voltage dependence of steady-state inactivation induced by g subunits.
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