G蛋白による神経型電位依存性Ca^<2+>チャネルの制御機構

概要

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G-protein-mediated inhibition of presynaptic voltage-dependent Ca^<2+> channels is comprised of voltage-dependent and -resistant components. The former is caused by a direct interaction of Ca^<2+> channel α_1 subunits with Gβγ, whereas the latter has not been well characterized. Here, we show that the N-terminus of Gα_0 is critical for the interaction with the C-terminus of the P/Q-type channel subunit, and that the binding induces voltage-resistant inhibition. A P/Q-type C-terminal peptide, an antiserum raised against the Gα_0 N-terminus, and a Gα_0 N-terminal peptide all attenuated the voltage-resistant inhibition of P/Q-type currents. Furthermore, the N-terminus of Gα_0 bound to the C-terminus of α_<1A> in vitro, which was prevented either by the P/Q-type channel C-terminal or Gα_0 N-terminal peptide. Although the C-terminal domain of the N-type channel showed similar ability to binding with Gα_0 N-terminus, the above-mentioned treatments were ineffective in the N-type channel current. These findings demonstrate that the voltage-resistant inhibition of the P/Q-type channel is caused by the interaction between the C-terminal domain of the Ca^<2+> channel α_<1A> subunit and the N-terminal region of Gα_0.
公益社団法人日本薬学会の論文
2002-08-01