Journal article
Kv1.5 channelopathy due to KCNA5 loss-of-function mutation causes human atrial fibrillation
Human molecular genetics, Vol.15(14), pp.2185-2191
2006
DOI: 10.1093/hmg/ddl143
PMID: 16772329
Abstract
Atrial fibrillation is a rhythm disorder characterized by chaotic electrical activity of cardiac atria. Predisposing to stroke and heart failure, this common condition is increasingly recognized as a heritable disorder. To identify genetic defects conferring disease susceptibility, patients with idiopathic atrial fibrillation, lacking traditional risk factors, were evaluated. Genomic DNA scanning revealed a nonsense mutation in KCNA5 that encodes Kv1.5, a voltage-gated potassium channel expressed in human atria. The heterozygous E375X mutation, present in a familial case of atrial fibrillation and absent in 540 unrelated control individuals, introduced a premature stop codon disrupting the Kv1.5 channel protein. The truncation eliminated the S4–S6 voltage sensor, pore region and C-terminus, preserving the N-terminus and S1–S3 transmembrane domains that secure tetrameric subunit assembly. Heterologously expressed recombinant E375X mutant failed to generate the ultrarapid delayed rectifier current IKur vital for atrial repolarization and exerted a dominant-negative effect on wild-type current. Loss of channel function translated into action potential prolongation and early after-depolarization in human atrial myocytes, increasing vulnerability to stress-provoked triggered activity. The pathogenic link between compromised Kv1.5 function and susceptibility to atrial fibrillation was verified, at the organism level, in a murine model. Rescue of the genetic defect was achieved by aminoglycoside-induced translational read-through of the E375X premature stop codon, restoring channel function. This first report of Kv1.5 loss-of-function channelopathy establishes KCNA5 mutation as a novel risk factor for repolarization deficiency and atrial fibrillation.
Details
- Title: Subtitle
- Kv1.5 channelopathy due to KCNA5 loss-of-function mutation causes human atrial fibrillation
- Creators
- Timothy M OLSON - Division of Cardiovascular Diseases, Department of Medicine, Mayo Clinic College of Medicine, Rochester, MN, United StatesAlexey E ALEKSEEV - Division of Cardiovascular Diseases, Department of Medicine, Mayo Clinic College of Medicine, Rochester, MN, United StatesXiaoke K LIU - Division of Cardiovascular Diseases, Department of Medicine, Mayo Clinic College of Medicine, Rochester, MN, United StatesSungjo PARK - Division of Cardiovascular Diseases, Department of Medicine, Mayo Clinic College of Medicine, Rochester, MN, United StatesLeonid V ZINGMAN - Division of Cardiovascular Diseases, Department of Medicine, Mayo Clinic College of Medicine, Rochester, MN, United StatesMartin BIENENGRAEBER - Division of Cardiovascular Diseases, Department of Medicine, Mayo Clinic College of Medicine, Rochester, MN, United StatesSrinivasan SATTIRAJU - Division of Cardiovascular Diseases, Department of Medicine, Mayo Clinic College of Medicine, Rochester, MN, United StatesJeffrey D BALLEW - Division of Cardiovascular Diseases, Department of Medicine, Mayo Clinic College of Medicine, Rochester, MN, United StatesArshad JAHANGIR - Division of Cardiovascular Diseases, Department of Medicine, Mayo Clinic College of Medicine, Rochester, MN, United StatesAndre TERZIC - Division of Cardiovascular Diseases, Department of Medicine, Mayo Clinic College of Medicine, Rochester, MN, United States
- Resource Type
- Journal article
- Publication Details
- Human molecular genetics, Vol.15(14), pp.2185-2191
- DOI
- 10.1093/hmg/ddl143
- PMID
- 16772329
- NLM abbreviation
- Hum Mol Genet
- ISSN
- 0964-6906
- eISSN
- 1460-2083
- Publisher
- Oxford University Press
- Language
- English
- Date published
- 2006
- Academic Unit
- Internal Medicine
- Record Identifier
- 9984094484402771
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