Mazzolini, 2018

2018 - Sci Rep. 2018 Jan 8;8(1):45. doi: 10.1038/s41598-017-18499-0

The gating mechanism in cyclic nucleotide-gated ion channels

Mazzolini M, Arcangeletti M, Marchesi A, Napolitano LMR, Grosa D, Maity S, Anselmi C, Torre V.

Abstract:

Cyclic nucleotide-gated (CNG) channels mediate transduction in several sensory neurons. These channels use the free energy of CNs' binding to open the pore, a process referred to as gating. CNG channels belong to the superfamily of voltage-gated channels, where the motion of the α-helix S6 controls gating in most of its members. To date, only the open, cGMP-bound, structure of a CNG channel has been determined at atomic resolution, which is inadequate to determine the molecular events underlying gating. By using electrophysiology, site-directed mutagenesis, chemical modification, and Single Molecule Force Spectroscopy, we demonstrate that opening of CNGA1 channels is initiated by the formation of salt bridges between residues in the C-linker and S5 helix. These events trigger conformational changes of the α-helix S5, transmitted to the P-helix and leading to channel opening. Therefore, the superfamily of voltage-gated channels shares a similar molecular architecture but has evolved divergent gating mechanisms

 

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