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Mutational analysis of state-dependent contacts in the pore module of eukaryotic sodium channels.

Publication ,  Journal Article
Du, Y; Tikhonov, DB; Nomura, Y; Dong, K; Zhorov, BS
Published in: Archives of biochemistry and biophysics
August 2018

Voltage-gated sodium channels have residues that change or may change contacts upon gating. Contributions of individual contacts in stability of different states are incompletely understood. Pore-lining inner helices contain exceptionally conserved asparagines in positions i20. Here we explored how mutations in positions i20 and i29 affect electrophysiological properties of insect sodium channels. In repeat interfaces I/IV, III/II and IV/III, alanine substitutions caused positive activation shifts in positions i20 and i29, negative shifts of slow inactivation in positions i20 and positive shifts of slow inactivation in positions i29. The results support the hypothesis on open state inter-repeat H-bonding of residues i20 and i29. The shift magnitudes vary between interfaces, reflecting structural asymmetry of the channels. Mutations in positions i20 of repeats III and IV caused much longer recovery delay from the slow and fast inactivation than other mutations. In repeat IV, alanine substitution of tyrosine i30 rescued positive activation shift of mutation in position i29. Our data suggest that polar residues in positions i29 are involved in stabilization of both the open and slow-inactivated states. Transition between the states may involve switching of H-bonding partners of residues i29 from the conserved asparagines to currently unknown residues.

Duke Scholars

Published In

Archives of biochemistry and biophysics

DOI

EISSN

1096-0384

ISSN

0003-9861

Publication Date

August 2018

Volume

652

Start / End Page

59 / 70

Related Subject Headings

  • Sodium Channels
  • Sequence Homology, Amino Acid
  • Mutation
  • Mutagenesis, Site-Directed
  • Ion Channel Gating
  • Insecta
  • Biochemistry & Molecular Biology
  • Animals
  • Amino Acid Sequence
  • 0601 Biochemistry and Cell Biology
 

Citation

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Du, Y., Tikhonov, D. B., Nomura, Y., Dong, K., & Zhorov, B. S. (2018). Mutational analysis of state-dependent contacts in the pore module of eukaryotic sodium channels. Archives of Biochemistry and Biophysics, 652, 59–70. https://doi.org/10.1016/j.abb.2018.06.008
Du, Yuzhe, Denis B. Tikhonov, Yoshiko Nomura, Ke Dong, and Boris S. Zhorov. “Mutational analysis of state-dependent contacts in the pore module of eukaryotic sodium channels.Archives of Biochemistry and Biophysics 652 (August 2018): 59–70. https://doi.org/10.1016/j.abb.2018.06.008.
Du Y, Tikhonov DB, Nomura Y, Dong K, Zhorov BS. Mutational analysis of state-dependent contacts in the pore module of eukaryotic sodium channels. Archives of biochemistry and biophysics. 2018 Aug;652:59–70.
Du, Yuzhe, et al. “Mutational analysis of state-dependent contacts in the pore module of eukaryotic sodium channels.Archives of Biochemistry and Biophysics, vol. 652, Aug. 2018, pp. 59–70. Epmc, doi:10.1016/j.abb.2018.06.008.
Du Y, Tikhonov DB, Nomura Y, Dong K, Zhorov BS. Mutational analysis of state-dependent contacts in the pore module of eukaryotic sodium channels. Archives of biochemistry and biophysics. 2018 Aug;652:59–70.
Journal cover image

Published In

Archives of biochemistry and biophysics

DOI

EISSN

1096-0384

ISSN

0003-9861

Publication Date

August 2018

Volume

652

Start / End Page

59 / 70

Related Subject Headings

  • Sodium Channels
  • Sequence Homology, Amino Acid
  • Mutation
  • Mutagenesis, Site-Directed
  • Ion Channel Gating
  • Insecta
  • Biochemistry & Molecular Biology
  • Animals
  • Amino Acid Sequence
  • 0601 Biochemistry and Cell Biology