title: PDZ domain-binding motif regulates cardiomyocyte compartment-specific NaV1.5 channel expression and function.
abstract: BACKGROUND
  Sodium channel NaV1.5 underlies cardiac excitability and conduction. The last 3 residues of NaV1.5 (Ser-Ile-Val) constitute a PDZ domain-binding motif that interacts with PDZ proteins such as syntrophins and SAP97 at different locations within the cardiomyocyte, thus defining distinct pools of NaV1.5 multiprotein complexes. Here, we explored the in vivo and clinical impact of this motif through characterization of mutant mice and genetic screening of patients.
  
  
  RESULTS
  To investigate in vivo the regulatory role of this motif, we generated knock-in mice lacking the SIV domain (ΔSIV). ΔSIV mice displayed reduced NaV1.5 expression and sodium current (INa), specifically at the lateral myocyte membrane, whereas NaV1.5 expression and INa at the intercalated disks were unaffected. Optical mapping of ΔSIV hearts revealed that ventricular conduction velocity was preferentially decreased in the transversal direction to myocardial fiber orientation, leading to increased anisotropy of ventricular conduction. Internalization of wild-type and ΔSIV channels was unchanged in HEK293 cells. However, the proteasome inhibitor MG132 rescued ΔSIV INa, suggesting that the SIV motif is important for regulation of NaV1.5 degradation. A missense mutation within the SIV motif (p.V2016M) was identified in a patient with Brugada syndrome. The mutation decreased NaV1.5 cell surface expression and INa when expressed in HEK293 cells.
  
  
  CONCLUSIONS
  Our results demonstrate the in vivo significance of the PDZ domain-binding motif in the correct expression of NaV1.5 at the lateral cardiomyocyte membrane and underline the functional role of lateral NaV1.5 in ventricular conduction. Furthermore, we reveal a clinical relevance of the SIV motif in cardiac disease.
authors.affiliation: From the Department of Clinical Research, University of Bern, Bern, Switzerland (D.S., L.G., J.O., M.A., J.-S.R., M.C.E., N.S., H.A.); Department of Anatomy, Embryology and Physiology (A.O.V.) and Department of Clinical and Experimental Cardiology (R.W., J.B., R.F.M., C.R.B., C.A.R.), Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands; ICIN-Netherlands Heart Institute, Utrecht, The Netherlands (J.B.); Center for Human and Clinical Genetics, Department of Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands (A.M.v.M.); Institute of Pathology, University of Lausanne, Lausanne, Switzerland (S.R.); Institut National de la Santé et de la Recherche Médicale (INSERM) Unité Mixte de Recherche 1087, L'Institut du Thorax, Nantes, France (R.R.); Centre National de la Recherche Scientifique Unité Mixte de Recherche 6291, Nantes, France (R.R.); Université de Nantes, Nantes, France (R.R.); and Centre Hospitalier Universitaire Nantes, L'Institut du Thorax, Service de Cardiologie, Nantes, France (R.R.).
authors.forename: Diana
authors.initials: D
authors.lastname: Shy
authors.affiliation: From the Department of Clinical Research, University of Bern, Bern, Switzerland (D.S., L.G., J.O., M.A., J.-S.R., M.C.E., N.S., H.A.); Department of Anatomy, Embryology and Physiology (A.O.V.) and Department of Clinical and Experimental Cardiology (R.W., J.B., R.F.M., C.R.B., C.A.R.), Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands; ICIN-Netherlands Heart Institute, Utrecht, The Netherlands (J.B.); Center for Human and Clinical Genetics, Department of Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands (A.M.v.M.); Institute of Pathology, University of Lausanne, Lausanne, Switzerland (S.R.); Institut National de la Santé et de la Recherche Médicale (INSERM) Unité Mixte de Recherche 1087, L'Institut du Thorax, Nantes, France (R.R.); Centre National de la Recherche Scientifique Unité Mixte de Recherche 6291, Nantes, France (R.R.); Université de Nantes, Nantes, France (R.R.); and Centre Hospitalier Universitaire Nantes, L'Institut du Thorax, Service de Cardiologie, Nantes, France (R.R.).
authors.forename: Ludovic
authors.initials: L
authors.lastname: Gillet
authors.affiliation: From the Department of Clinical Research, University of Bern, Bern, Switzerland (D.S., L.G., J.O., M.A., J.-S.R., M.C.E., N.S., H.A.); Department of Anatomy, Embryology and Physiology (A.O.V.) and Department of Clinical and Experimental Cardiology (R.W., J.B., R.F.M., C.R.B., C.A.R.), Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands; ICIN-Netherlands Heart Institute, Utrecht, The Netherlands (J.B.); Center for Human and Clinical Genetics, Department of Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands (A.M.v.M.); Institute of Pathology, University of Lausanne, Lausanne, Switzerland (S.R.); Institut National de la Santé et de la Recherche Médicale (INSERM) Unité Mixte de Recherche 1087, L'Institut du Thorax, Nantes, France (R.R.); Centre National de la Recherche Scientifique Unité Mixte de Recherche 6291, Nantes, France (R.R.); Université de Nantes, Nantes, France (R.R.); and Centre Hospitalier Universitaire Nantes, L'Institut du Thorax, Service de Cardiologie, Nantes, France (R.R.).
authors.forename: Jakob
authors.initials: J
authors.lastname: Ogrodnik
authors.affiliation: From the Department of Clinical Research, University of Bern, Bern, Switzerland (D.S., L.G., J.O., M.A., J.-S.R., M.C.E., N.S., H.A.); Department of Anatomy, Embryology and Physiology (A.O.V.) and Department of Clinical and Experimental Cardiology (R.W., J.B., R.F.M., C.R.B., C.A.R.), Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands; ICIN-Netherlands Heart Institute, Utrecht, The Netherlands (J.B.); Center for Human and Clinical Genetics, Department of Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands (A.M.v.M.); Institute of Pathology, University of Lausanne, Lausanne, Switzerland (S.R.); Institut National de la Santé et de la Recherche Médicale (INSERM) Unité Mixte de Recherche 1087, L'Institut du Thorax, Nantes, France (R.R.); Centre National de la Recherche Scientifique Unité Mixte de Recherche 6291, Nantes, France (R.R.); Université de Nantes, Nantes, France (R.R.); and Centre Hospitalier Universitaire Nantes, L'Institut du Thorax, Service de Cardiologie, Nantes, France (R.R.).
authors.forename: Maxime
authors.initials: M
authors.lastname: Albesa
authors.affiliation: From the Department of Clinical Research, University of Bern, Bern, Switzerland (D.S., L.G., J.O., M.A., J.-S.R., M.C.E., N.S., H.A.); Department of Anatomy, Embryology and Physiology (A.O.V.) and Department of Clinical and Experimental Cardiology (R.W., J.B., R.F.M., C.R.B., C.A.R.), Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands; ICIN-Netherlands Heart Institute, Utrecht, The Netherlands (J.B.); Center for Human and Clinical Genetics, Department of Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands (A.M.v.M.); Institute of Pathology, University of Lausanne, Lausanne, Switzerland (S.R.); Institut National de la Santé et de la Recherche Médicale (INSERM) Unité Mixte de Recherche 1087, L'Institut du Thorax, Nantes, France (R.R.); Centre National de la Recherche Scientifique Unité Mixte de Recherche 6291, Nantes, France (R.R.); Université de Nantes, Nantes, France (R.R.); and Centre Hospitalier Universitaire Nantes, L'Institut du Thorax, Service de Cardiologie, Nantes, France (R.R.).
authors.forename: Arie O
authors.initials: AO
authors.lastname: Verkerk
authors.affiliation: From the Department of Clinical Research, University of Bern, Bern, Switzerland (D.S., L.G., J.O., M.A., J.-S.R., M.C.E., N.S., H.A.); Department of Anatomy, Embryology and Physiology (A.O.V.) and Department of Clinical and Experimental Cardiology (R.W., J.B., R.F.M., C.R.B., C.A.R.), Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands; ICIN-Netherlands Heart Institute, Utrecht, The Netherlands (J.B.); Center for Human and Clinical Genetics, Department of Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands (A.M.v.M.); Institute of Pathology, University of Lausanne, Lausanne, Switzerland (S.R.); Institut National de la Santé et de la Recherche Médicale (INSERM) Unité Mixte de Recherche 1087, L'Institut du Thorax, Nantes, France (R.R.); Centre National de la Recherche Scientifique Unité Mixte de Recherche 6291, Nantes, France (R.R.); Université de Nantes, Nantes, France (R.R.); and Centre Hospitalier Universitaire Nantes, L'Institut du Thorax, Service de Cardiologie, Nantes, France (R.R.).
authors.forename: Rianne
authors.initials: R
authors.lastname: Wolswinkel
authors.affiliation: From the Department of Clinical Research, University of Bern, Bern, Switzerland (D.S., L.G., J.O., M.A., J.-S.R., M.C.E., N.S., H.A.); Department of Anatomy, Embryology and Physiology (A.O.V.) and Department of Clinical and Experimental Cardiology (R.W., J.B., R.F.M., C.R.B., C.A.R.), Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands; ICIN-Netherlands Heart Institute, Utrecht, The Netherlands (J.B.); Center for Human and Clinical Genetics, Department of Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands (A.M.v.M.); Institute of Pathology, University of Lausanne, Lausanne, Switzerland (S.R.); Institut National de la Santé et de la Recherche Médicale (INSERM) Unité Mixte de Recherche 1087, L'Institut du Thorax, Nantes, France (R.R.); Centre National de la Recherche Scientifique Unité Mixte de Recherche 6291, Nantes, France (R.R.); Université de Nantes, Nantes, France (R.R.); and Centre Hospitalier Universitaire Nantes, L'Institut du Thorax, Service de Cardiologie, Nantes, France (R.R.).
authors.forename: Jean-Sébastien
authors.initials: JS
authors.lastname: Rougier
authors.affiliation: From the Department of Clinical Research, University of Bern, Bern, Switzerland (D.S., L.G., J.O., M.A., J.-S.R., M.C.E., N.S., H.A.); Department of Anatomy, Embryology and Physiology (A.O.V.) and Department of Clinical and Experimental Cardiology (R.W., J.B., R.F.M., C.R.B., C.A.R.), Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands; ICIN-Netherlands Heart Institute, Utrecht, The Netherlands (J.B.); Center for Human and Clinical Genetics, Department of Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands (A.M.v.M.); Institute of Pathology, University of Lausanne, Lausanne, Switzerland (S.R.); Institut National de la Santé et de la Recherche Médicale (INSERM) Unité Mixte de Recherche 1087, L'Institut du Thorax, Nantes, France (R.R.); Centre National de la Recherche Scientifique Unité Mixte de Recherche 6291, Nantes, France (R.R.); Université de Nantes, Nantes, France (R.R.); and Centre Hospitalier Universitaire Nantes, L'Institut du Thorax, Service de Cardiologie, Nantes, France (R.R.).
authors.forename: Julien
authors.initials: J
authors.lastname: Barc
authors.affiliation: From the Department of Clinical Research, University of Bern, Bern, Switzerland (D.S., L.G., J.O., M.A., J.-S.R., M.C.E., N.S., H.A.); Department of Anatomy, Embryology and Physiology (A.O.V.) and Department of Clinical and Experimental Cardiology (R.W., J.B., R.F.M., C.R.B., C.A.R.), Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands; ICIN-Netherlands Heart Institute, Utrecht, The Netherlands (J.B.); Center for Human and Clinical Genetics, Department of Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands (A.M.v.M.); Institute of Pathology, University of Lausanne, Lausanne, Switzerland (S.R.); Institut National de la Santé et de la Recherche Médicale (INSERM) Unité Mixte de Recherche 1087, L'Institut du Thorax, Nantes, France (R.R.); Centre National de la Recherche Scientifique Unité Mixte de Recherche 6291, Nantes, France (R.R.); Université de Nantes, Nantes, France (R.R.); and Centre Hospitalier Universitaire Nantes, L'Institut du Thorax, Service de Cardiologie, Nantes, France (R.R.).
authors.forename: Maria C
authors.initials: MC
authors.lastname: Essers
authors.affiliation: From the Department of Clinical Research, University of Bern, Bern, Switzerland (D.S., L.G., J.O., M.A., J.-S.R., M.C.E., N.S., H.A.); Department of Anatomy, Embryology and Physiology (A.O.V.) and Department of Clinical and Experimental Cardiology (R.W., J.B., R.F.M., C.R.B., C.A.R.), Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands; ICIN-Netherlands Heart Institute, Utrecht, The Netherlands (J.B.); Center for Human and Clinical Genetics, Department of Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands (A.M.v.M.); Institute of Pathology, University of Lausanne, Lausanne, Switzerland (S.R.); Institut National de la Santé et de la Recherche Médicale (INSERM) Unité Mixte de Recherche 1087, L'Institut du Thorax, Nantes, France (R.R.); Centre National de la Recherche Scientifique Unité Mixte de Recherche 6291, Nantes, France (R.R.); Université de Nantes, Nantes, France (R.R.); and Centre Hospitalier Universitaire Nantes, L'Institut du Thorax, Service de Cardiologie, Nantes, France (R.R.).
authors.forename: Ninda
authors.initials: N
authors.lastname: Syam
authors.affiliation: From the Department of Clinical Research, University of Bern, Bern, Switzerland (D.S., L.G., J.O., M.A., J.-S.R., M.C.E., N.S., H.A.); Department of Anatomy, Embryology and Physiology (A.O.V.) and Department of Clinical and Experimental Cardiology (R.W., J.B., R.F.M., C.R.B., C.A.R.), Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands; ICIN-Netherlands Heart Institute, Utrecht, The Netherlands (J.B.); Center for Human and Clinical Genetics, Department of Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands (A.M.v.M.); Institute of Pathology, University of Lausanne, Lausanne, Switzerland (S.R.); Institut National de la Santé et de la Recherche Médicale (INSERM) Unité Mixte de Recherche 1087, L'Institut du Thorax, Nantes, France (R.R.); Centre National de la Recherche Scientifique Unité Mixte de Recherche 6291, Nantes, France (R.R.); Université de Nantes, Nantes, France (R.R.); and Centre Hospitalier Universitaire Nantes, L'Institut du Thorax, Service de Cardiologie, Nantes, France (R.R.).
authors.forename: Roos F
authors.initials: RF
authors.lastname: Marsman
authors.affiliation: From the Department of Clinical Research, University of Bern, Bern, Switzerland (D.S., L.G., J.O., M.A., J.-S.R., M.C.E., N.S., H.A.); Department of Anatomy, Embryology and Physiology (A.O.V.) and Department of Clinical and Experimental Cardiology (R.W., J.B., R.F.M., C.R.B., C.A.R.), Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands; ICIN-Netherlands Heart Institute, Utrecht, The Netherlands (J.B.); Center for Human and Clinical Genetics, Department of Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands (A.M.v.M.); Institute of Pathology, University of Lausanne, Lausanne, Switzerland (S.R.); Institut National de la Santé et de la Recherche Médicale (INSERM) Unité Mixte de Recherche 1087, L'Institut du Thorax, Nantes, France (R.R.); Centre National de la Recherche Scientifique Unité Mixte de Recherche 6291, Nantes, France (R.R.); Université de Nantes, Nantes, France (R.R.); and Centre Hospitalier Universitaire Nantes, L'Institut du Thorax, Service de Cardiologie, Nantes, France (R.R.).
authors.forename: Anneke M
authors.initials: AM
authors.lastname: van Mil
authors.affiliation: From the Department of Clinical Research, University of Bern, Bern, Switzerland (D.S., L.G., J.O., M.A., J.-S.R., M.C.E., N.S., H.A.); Department of Anatomy, Embryology and Physiology (A.O.V.) and Department of Clinical and Experimental Cardiology (R.W., J.B., R.F.M., C.R.B., C.A.R.), Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands; ICIN-Netherlands Heart Institute, Utrecht, The Netherlands (J.B.); Center for Human and Clinical Genetics, Department of Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands (A.M.v.M.); Institute of Pathology, University of Lausanne, Lausanne, Switzerland (S.R.); Institut National de la Santé et de la Recherche Médicale (INSERM) Unité Mixte de Recherche 1087, L'Institut du Thorax, Nantes, France (R.R.); Centre National de la Recherche Scientifique Unité Mixte de Recherche 6291, Nantes, France (R.R.); Université de Nantes, Nantes, France (R.R.); and Centre Hospitalier Universitaire Nantes, L'Institut du Thorax, Service de Cardiologie, Nantes, France (R.R.).
authors.forename: Samuel
authors.initials: S
authors.lastname: Rotman
authors.affiliation: From the Department of Clinical Research, University of Bern, Bern, Switzerland (D.S., L.G., J.O., M.A., J.-S.R., M.C.E., N.S., H.A.); Department of Anatomy, Embryology and Physiology (A.O.V.) and Department of Clinical and Experimental Cardiology (R.W., J.B., R.F.M., C.R.B., C.A.R.), Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands; ICIN-Netherlands Heart Institute, Utrecht, The Netherlands (J.B.); Center for Human and Clinical Genetics, Department of Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands (A.M.v.M.); Institute of Pathology, University of Lausanne, Lausanne, Switzerland (S.R.); Institut National de la Santé et de la Recherche Médicale (INSERM) Unité Mixte de Recherche 1087, L'Institut du Thorax, Nantes, France (R.R.); Centre National de la Recherche Scientifique Unité Mixte de Recherche 6291, Nantes, France (R.R.); Université de Nantes, Nantes, France (R.R.); and Centre Hospitalier Universitaire Nantes, L'Institut du Thorax, Service de Cardiologie, Nantes, France (R.R.).
authors.forename: Richard
authors.initials: R
authors.lastname: Redon
authors.affiliation: From the Department of Clinical Research, University of Bern, Bern, Switzerland (D.S., L.G., J.O., M.A., J.-S.R., M.C.E., N.S., H.A.); Department of Anatomy, Embryology and Physiology (A.O.V.) and Department of Clinical and Experimental Cardiology (R.W., J.B., R.F.M., C.R.B., C.A.R.), Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands; ICIN-Netherlands Heart Institute, Utrecht, The Netherlands (J.B.); Center for Human and Clinical Genetics, Department of Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands (A.M.v.M.); Institute of Pathology, University of Lausanne, Lausanne, Switzerland (S.R.); Institut National de la Santé et de la Recherche Médicale (INSERM) Unité Mixte de Recherche 1087, L'Institut du Thorax, Nantes, France (R.R.); Centre National de la Recherche Scientifique Unité Mixte de Recherche 6291, Nantes, France (R.R.); Université de Nantes, Nantes, France (R.R.); and Centre Hospitalier Universitaire Nantes, L'Institut du Thorax, Service de Cardiologie, Nantes, France (R.R.).
authors.forename: Connie R
authors.initials: CR
authors.lastname: Bezzina
authors.affiliation: From the Department of Clinical Research, University of Bern, Bern, Switzerland (D.S., L.G., J.O., M.A., J.-S.R., M.C.E., N.S., H.A.); Department of Anatomy, Embryology and Physiology (A.O.V.) and Department of Clinical and Experimental Cardiology (R.W., J.B., R.F.M., C.R.B., C.A.R.), Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands; ICIN-Netherlands Heart Institute, Utrecht, The Netherlands (J.B.); Center for Human and Clinical Genetics, Department of Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands (A.M.v.M.); Institute of Pathology, University of Lausanne, Lausanne, Switzerland (S.R.); Institut National de la Santé et de la Recherche Médicale (INSERM) Unité Mixte de Recherche 1087, L'Institut du Thorax, Nantes, France (R.R.); Centre National de la Recherche Scientifique Unité Mixte de Recherche 6291, Nantes, France (R.R.); Université de Nantes, Nantes, France (R.R.); and Centre Hospitalier Universitaire Nantes, L'Institut du Thorax, Service de Cardiologie, Nantes, France (R.R.).
authors.forename: Carol Ann
authors.initials: CA
authors.lastname: Remme
authors.affiliation: From the Department of Clinical Research, University of Bern, Bern, Switzerland (D.S., L.G., J.O., M.A., J.-S.R., M.C.E., N.S., H.A.); Department of Anatomy, Embryology and Physiology (A.O.V.) and Department of Clinical and Experimental Cardiology (R.W., J.B., R.F.M., C.R.B., C.A.R.), Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands; ICIN-Netherlands Heart Institute, Utrecht, The Netherlands (J.B.); Center for Human and Clinical Genetics, Department of Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands (A.M.v.M.); Institute of Pathology, University of Lausanne, Lausanne, Switzerland (S.R.); Institut National de la Santé et de la Recherche Médicale (INSERM) Unité Mixte de Recherche 1087, L'Institut du Thorax, Nantes, France (R.R.); Centre National de la Recherche Scientifique Unité Mixte de Recherche 6291, Nantes, France (R.R.); Université de Nantes, Nantes, France (R.R.); and Centre Hospitalier Universitaire Nantes, L'Institut du Thorax, Service de Cardiologie, Nantes, France (R.R.). Hugues.Abriel@dkf.unibe.ch.
authors.forename: Hugues
authors.initials: H
authors.lastname: Abriel
mesh_terms: D000818:Animals; D005786:Gene Expression Regulation; D055879:Gene Knock-In Techniques; D057809:HEK293 Cells; D006801:Humans; D051379:Mice; D032383:Myocytes, Cardiac / Q000378:metabolism*; D062554:NAV1.5 Voltage-Gated Sodium Channel / Q000096:biosynthesis* / Q000502:physiology; D054731:PDZ Domains / Q000502:physiology*; D054730:Protein Interaction Domains and Motifs / Q000502:physiology*
chemical_list: D062554:NAV1.5 Voltage-Gated Sodium Channel; C568321:Scn5a protein, mouse
keywords: dystrophin; sodium channels; syntrophin