Extracellular Kir2.1(C122Y) Mutant Upsets Kir2.1-PIP(2) Bonds and Is Arrhythmogenic in Andersen-Tawil Syndrome.

Fecha de publicación: 12/04/2024 Fecha Ahead of Print: 18/03/2024

Autores de IIS La Fe

Participantes ajenos a IIS La Fe

Cruz FM
Macías Á
Moreno-Manuel AI
Gutiérrez LK
Vera-Pedrosa ML
Martínez-Carrascoso I
Ruiz Robles JM
Bermúdez-Jiménez FJ
Díaz-Agustín A
Martínez de Benito F
Arias-Santiago S
Martín-Martínez M
Gutierrez-Rodríguez M
Bernal JA
Jiménez-Jaimez J
Jalife J

Grupos

Cardiopatías familiares, muerte súbita y mecanismos de enfermedad (CAFAMUSME)

Investigador Principal

Aitana Braza Boils

Abstract

BACKGROUND: Andersen-Tawil syndrome type 1 is a rare heritable disease caused by mutations in the gene coding the strong inwardly rectifying K(+) channel Kir2.1. The extracellular Cys (cysteine)(122)-to-Cys(154) disulfide bond in the channel structure is crucial for proper folding but has not been associated with correct channel function at the membrane. We evaluated whether a human mutation at the Cys(122)-to-Cys(154) disulfide bridge leads to Kir2.1 channel dysfunction and arrhythmias by reorganizing the overall Kir2.1 channel structure and destabilizing its open state. METHODS: We identified a Kir2.1 loss-of-function mutation (c.366 A>T; p.Cys122Tyr) in an ATS1 family. To investigate its pathophysiological implications, we generated an AAV9-mediated cardiac-specific mouse model expressing the Kir2.1(C122Y) variant. We employed a multidisciplinary approach, integrating patch clamping and intracardiac stimulation, molecular biology techniques, molecular dynamics, and bioluminescence resonance energy transfer experiments. RESULTS: Kir2.1(C122Y) mice recapitulated the ECG features of ATS1 independently of sex, including corrected QT prolongation, conduction defects, and increased arrhythmia susceptibility. Isolated Kir2.1(C122Y) cardiomyocytes showed significantly reduced inwardly rectifier K+ (I(K1)) and inward Na+ (I(Na)) current densities independently of normal trafficking. Molecular dynamics predicted that the C122Y mutation provoked a conformational change over the 2000-ns simulation, characterized by a greater loss of hydrogen bonds between Kir2.1 and phosphatidylinositol 4,5-bisphosphate than wild type (WT). Therefore, the phosphatidylinositol 4,5-bisphosphate-binding pocket was destabilized, resulting in a lower conductance state compared with WT. Accordingly, on inside-out patch clamping, the C122Y mutation significantly blunted Kir2.1 sensitivity to increasing phosphatidylinositol 4,5-bisphosphate concentrations. In addition, the Kir2.1(C122Y) mutation resulted in channelosome degradation, demonstrating temporal instability of both Kir2.1 and Na(V)1.5 proteins. CONCLUSIONS: The extracellular Cys(122)-to-Cys(154) disulfide bond in the tridimensional Kir2.1 channel structure is essential for the channel function. We demonstrate that breaking disulfide bonds in the extracellular domain disrupts phosphatidylinositol 4,5-bisphosphate-dependent regulation, leading to channel dysfunction and defects in Kir2.1 energetic stability. The mutation also alters functional expression of the Na(V)1.5 channel and ultimately leads to conduction disturbances and life-threatening arrhythmia characteristic of Andersen-Tawil syndrome type 1.

Datos de la publicación

ISSN/ISSNe:: 0009-7330, 1524-4571
Tipo:: Article
Páginas:: 52-71
DOI:: 10.1161/CIRCRESAHA.123.323895
Factor de Impacto:: 4,709 SCImago ℠
Cuartil:: Q1 SCImago ℠

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Filiaciones

Bermúdez-Jiménez FJ:: Servicio de Cardiología (F.J.B.-J., J.J.-J.), Hospital Universitario Virgen de las Nieves, Granada, Spain
Arias-Santiago S:: Servicio de Dermatología (S.A.-S.), Hospital Universitario Virgen de las Nieves, Granada, Spain
Braza-Boils A:: Instituto de Investigación. Unit of Inherited Cardiomyopathies and Sudden Death (CAFAMUSME [Unidad de Cardiopatías Familiares, Muerte Súbita y Mecanismos de Enfermedad]), Health Research Institute La Fe, La Fe Hospital, Valencia, Spain (A.B.-B., E.Z.)
Zorio E:: Instituto de Investigación. Unit of Inherited Cardiomyopathies and Sudden Death (CAFAMUSME [Unidad de Cardiopatías Familiares, Muerte Súbita y Mecanismos de Enfermedad]), Health Research Institute La Fe, La Fe Hospital, Valencia, Spain (A.B.-B., E.Z.)
Jiménez-Jaimez J:: Servicio de Cardiología (F.J.B.-J., J.J.-J.), Hospital Universitario Virgen de las Nieves, Granada, Spain

Keywords

andersen syndrome; arrhythmias, cardiac; death, sudden, cardiac; membrane potentials; organisms, genetically modified; tachycardia, ventricular; ventricular fibrillation

Proyectos asociados

RED INVESTIGACION (RECAVA)

RD06/0014/0004 . INSTITUTO DE SALUD CARLOS III; FUNDACION PARA LA INV BIOMEDICA- HOSPITAL GREGORIO MARAÑON; FUNDACIÓN PARA LA INVESTIGACIÓN DEL HOSPITAL UNIVERSITARIO LA FE DE LA COMUNIDAD VALENCIANA . 2006