Structural basis for C-type inactivation in a Shaker family voltage-gated K<sup>+</sup> channel.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 35452285.
- Also identified by DOI 10.1126/sciadv.abm8804 and PMC identifier 9032944.
- Licence recorded as CC BY-NC.
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Abstract
C-type inactivation is a process by which ion flux through a voltage-gated K<sup>+</sup> (K<sub>v</sub>) channel is regulated at the selectivity filter. While prior studies have indicated that C-type inactivation involves structural changes at the selectivity filter, the nature of the changes has not been resolved. Here, we report the crystal structure of the K<sub>v</sub>1.2 channel in a C-type inactivated state. The structure shows that C-type inactivation involves changes in the selectivity filter that disrupt the outer two ion binding sites in the filter. The changes at the selectivity filter propagate to the extracellular mouth and the turret regions of the channel pore. The structural changes observed are consistent with the functional hallmarks of C-type inactivation. This study highlights the intricate interplay between K<sup>+</sup> occupancy at the ion binding sites and the interactions of the selectivity filter in determining the balance between the conductive and the inactivated conformations of the filter.