Ankyrin-B Mutation Causes Type 4 long-QT Cardiac Arrhythmia and Sudden Cardiac Death

Nature. 2003 Feb 6;421(6923):634-9. doi: 10.1038/nature01335.

Abstract

Mutations in ion channels involved in the generation and termination of action potentials constitute a family of molecular defects that underlie fatal cardiac arrhythmias in inherited long-QT syndrome. We report here that a loss-of-function (E1425G) mutation in ankyrin-B (also known as ankyrin 2), a member of a family of versatile membrane adapters, causes dominantly inherited type 4 long-QT cardiac arrhythmia in humans. Mice heterozygous for a null mutation in ankyrin-B are haploinsufficient and display arrhythmia similar to humans. Mutation of ankyrin-B results in disruption in the cellular organization of the sodium pump, the sodium/calcium exchanger, and inositol-1,4,5-trisphosphate receptors (all ankyrin-B-binding proteins), which reduces the targeting of these proteins to the transverse tubules as well as reducing overall protein level. Ankyrin-B mutation also leads to altered Ca2+ signalling in adult cardiomyocytes that results in extrasystoles, and provides a rationale for the arrhythmia. Thus, we identify a new mechanism for cardiac arrhythmia due to abnormal coordination of multiple functionally related ion channels and transporters.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Action Potentials
  • Animals
  • Ankyrins / genetics*
  • Ankyrins / physiology
  • Bradycardia / complications
  • Bradycardia / genetics
  • Bradycardia / metabolism
  • Bradycardia / physiopathology
  • Calcium Channels / metabolism
  • Calcium Signaling
  • Death, Sudden, Cardiac / etiology*
  • Electrocardiography
  • Female
  • Heart / physiopathology
  • Heart Rate
  • Heterozygote
  • Humans
  • Inositol 1,4,5-Trisphosphate Receptors
  • Long QT Syndrome / classification
  • Long QT Syndrome / genetics*
  • Long QT Syndrome / metabolism
  • Long QT Syndrome / physiopathology
  • Male
  • Mice
  • Mutation / genetics*
  • Myocardium / metabolism
  • Myocardium / pathology
  • Patch-Clamp Techniques
  • Pedigree
  • Phenotype
  • Protein Binding
  • Receptors, Cytoplasmic and Nuclear / metabolism
  • Sodium-Calcium Exchanger / metabolism
  • Sodium-Potassium-Exchanging ATPase / metabolism

Substances

  • ANK2 protein, human
  • Ank2 protein, mouse
  • Ankyrins
  • Calcium Channels
  • ITPR1 protein, human
  • Inositol 1,4,5-Trisphosphate Receptors
  • Receptors, Cytoplasmic and Nuclear
  • Sodium-Calcium Exchanger
  • Sodium-Potassium-Exchanging ATPase