Electromechanical coupling of the Kv1.1 voltage-gated K+ channel is fine-tuned by the simplest amino acid residue in the S4-S5 linker


Investigating the Shaker-related K+ channel Kv1.1, the dysfunction of which is responsible for episodic ataxia 1 (EA1), at the functional and molecular level provides valuable understandings on normal channel dynamics, structural correlates underlying voltage-gating, and disease-causing mechanisms. Most studies focused on apparently functional amino acid residues composing voltage-gated K+ channels, neglecting the simplest ones. Glycine at position 311 of Kv1.1 is highly conserved both evolutionarily and within the Kv channel superfamily, is located in a region functionally relevant (the S4-S5 linker), and results in overt disease when mutated (p.G311D). By mutating the G311 residue to aspartate, we show here that the channel voltage-gating, activation, deactivation, inactivation, and window currents are markedly affected. In silico, modeling shows this glycine residue is strategically placed at one end of the linker helix which must be free to both bend and move past other portions of the protein during the channel’s opening and closing. This is befitting of a glycine residue as its small neutral side chain allows for movement unhindered by interaction with any other amino acid. Results presented reveal the crucial importance of a distinct glycine residue, within the S4-S5 linker, in the voltage-dependent electromechanical coupling that control channel gating.

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Availability of data and material

Derived data supporting the findings of this study are available from the corresponding author CMD on request.



Episodic ataxia type 1




Potassium voltage-gated channel

Kv1.1WT :

Wildtype potassium 1.1 voltage-gated channel

Kv1.1G311D :

Mutant potassium voltage-gated channel

Kv1.1WT/G311D :

Heteromeric wildtype and mutant potassium voltage-gated channel


Pore domain


Prediction of proteins in membrane




Two-electrode voltage-clamp




Voltage-sensing domain




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Lorena Coretti is an Alfredo Leonardi’s foundation fellow.


This study is financially supported by the University of Malta Research, Innovation & Development Trust (RIDT) (Grant No. I20LU08, BooKind E20LG42) and of the United Arab Emirates University (Grants Nos. 31M452 and 31M468).

Author information




SH conducted statistics, analyzed the data, prepared the figures, and wrote the article. AM, MC, LC, FMB, and PI conducted molecular biology and electrophysiology experiments. TH and GH did channel modeling and channel structure analysis and contributed in the writing of the paper. HWMS and MP provided advice, consultation, and contributed in writing the paper. MCD planned experimental protocols, coordinated with all authors, supervised the work, and contributed in writing the paper.

Corresponding author

Correspondence to Maria Cristina D’Adamo.

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Procedures involving Xenopus laevis were in accordance with international standards of animal care, the Maltese Animal Welfare Act, and the NIH Guide for the Care and Use of Laboratory Animals. The procedure was approved by the local Veterinary Service Authority.

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This article is part of the special issue on Channelopathies: from mutation to diseases in Pflügers Archiv—European Journal of Physiology

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Hasan, S., Megaro, A., Cenciarini, M. et al. Electromechanical coupling of the Kv1.1 voltage-gated K+ channel is fine-tuned by the simplest amino acid residue in the S4-S5 linker. Pflugers Arch - Eur J Physiol (2020). https://doi.org/10.1007/s00424-020-02414-0

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  • Episodic ataxia type 1
  • Kv1.1
  • Kv
  • S4-S5 linker
  • KCNA1
  • Xenopus laevis