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Functional Consequences of the SCN5A-p.Y1977N Mutation within the PY Ubiquitylation Motif: Discrepancy between HEK293 Cells and Transgenic Mice.

  • Casini S Department of Clinical and Experimental Cardiology, Heart Centre, Amsterdam UMC, Location Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 Amsterdam, The Netherlands. s.casini@amsterdamumc.nl.
  • Albesa M Ion Channels and Channelopathies Laboratory, Institute for Biochemistry and Molecular Medicine, University of Bern, Bühlstrasse 28, 3012 Bern, Switzerland. maxime.albesa@zeiss.com.
  • Wang Z Ion Channels and Channelopathies Laboratory, Institute for Biochemistry and Molecular Medicine, University of Bern, Bühlstrasse 28, 3012 Bern, Switzerland. zizun.wang@ibmm.unibe.ch.
  • Portero V Department of Clinical and Experimental Cardiology, Heart Centre, Amsterdam UMC, Location Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 Amsterdam, The Netherlands. v.m.portero@amsterdamumc.nl.
  • Ross-Kaschitza D Ion Channels and Channelopathies Laboratory, Institute for Biochemistry and Molecular Medicine, University of Bern, Bühlstrasse 28, 3012 Bern, Switzerland. daniela.ross@ibmm.unibe.ch.
  • Rougier JS Ion Channels and Channelopathies Laboratory, Institute for Biochemistry and Molecular Medicine, University of Bern, Bühlstrasse 28, 3012 Bern, Switzerland. jean-sebastien.rougier@ibmm.unibe.ch.
  • Marchal GA Department of Clinical and Experimental Cardiology, Heart Centre, Amsterdam UMC, Location Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 Amsterdam, The Netherlands. g.a.marchal@amsterdamumc.nl.
  • Chung WK Departments of Pediatrics & Medicine, Columbia University Medical Center, 1150 St Nicholas Avenue, New York, NY 10032, USA. wkc15@cumc.columbia.edu.
  • Bezzina CR Department of Clinical and Experimental Cardiology, Heart Centre, Amsterdam UMC, Location Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 Amsterdam, The Netherlands. c.r.bezzina@amsterdamumc.nl.
  • Abriel H Ion Channels and Channelopathies Laboratory, Institute for Biochemistry and Molecular Medicine, University of Bern, Bühlstrasse 28, 3012 Bern, Switzerland. Hugues.Abriel@ibmm.unibe.ch.
  • Remme CA Department of Clinical and Experimental Cardiology, Heart Centre, Amsterdam UMC, Location Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 Amsterdam, The Netherlands. c.a.remme@amsterdamumc.nl.
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  • 2019-10-17
Published in:
  • International journal of molecular sciences. - 2019
Nedd4-2
SCN5A
action potential
long QT syndrome
mouse model
patch-clamp
sodium current
ubiquitylation
Amino Acid Motifs
Amino Acid Substitution
Animals
Female
Gene Knock-In Techniques
HEK293 Cells
Humans
Long QT Syndrome
Mice
Mice, Transgenic
NAV1.5 Voltage-Gated Sodium Channel
Nedd4 Ubiquitin Protein Ligases
Protein Binding
Ubiquitination
Young Adult
English Dysfunction of the cardiac sodium channel Nav1.5 (encoded by the SCN5A gene) is associated with arrhythmias and sudden cardiac death. SCN5A mutations associated with long QT syndrome type 3 (LQT3) lead to enhanced late sodium current and consequent action potential (AP) prolongation. Internalization and degradation of Nav1.5 is regulated by ubiquitylation, a post-translational mechanism that involves binding of the ubiquitin ligase Nedd4-2 to a proline-proline-serine-tyrosine sequence of Nav1.5, designated the PY-motif. We investigated the biophysical properties of the LQT3-associated SCN5A-p.Y1977N mutation located in the Nav1.5 PY-motif, both in HEK293 cells as well as in newly generated mice harboring the mouse homolog mutation Scn5a-p.Y1981N. We found that in HEK293 cells, the SCN5A-p.Y1977N mutation abolished the interaction between Nav1.5 and Nedd4-2, suppressed PY-motif-dependent ubiquitylation of Nav1.5, and consequently abrogated Nedd4-2 induced sodium current (INa) decrease. Nevertheless, homozygous mice harboring the Scn5a-p.Y1981N mutation showed no electrophysiological alterations nor changes in AP or (late) INa properties, questioning the in vivo relevance of the PY-motif. Our findings suggest the presence of compensatory mechanisms, with additional, as yet unknown, factors likely required to reduce the "ubiquitylation reserve" of Nav1.5. Future identification of such modulatory factors may identify potential triggers for arrhythmias and sudden cardiac death in the setting of LQT3 mutations.
Language
  • English
Open access status
gold
Identifiers
Persistent URL
https://sonar.ch/global/documents/185151
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