Extracellular cysteine disulfide bond break at Cys122 disrupts PIP 2 -dependent Kir2.1 channel function and leads to arrhythmias in Andersen-Tawil Syndrome.

Autor: Cruz FM; Centro Nacional de Investigaciones Cardiovasculares (CNIC), 28029 Madrid, Spain., Macías Á; Centro Nacional de Investigaciones Cardiovasculares (CNIC), 28029 Madrid, Spain., Moreno-Manuel AI; Centro Nacional de Investigaciones Cardiovasculares (CNIC), 28029 Madrid, Spain., Gutiérrez LK; Centro Nacional de Investigaciones Cardiovasculares (CNIC), 28029 Madrid, Spain., Vera-Pedrosa ML; Centro Nacional de Investigaciones Cardiovasculares (CNIC), 28029 Madrid, Spain., Martínez-Carrascoso I; Centro Nacional de Investigaciones Cardiovasculares (CNIC), 28029 Madrid, Spain., Pérez PS; Centro Nacional de Investigaciones Cardiovasculares (CNIC), 28029 Madrid, Spain., Robles JMR; Centro Nacional de Investigaciones Cardiovasculares (CNIC), 28029 Madrid, Spain., Bermúdez-Jiménez FJ; Centro Nacional de Investigaciones Cardiovasculares (CNIC), 28029 Madrid, Spain.; Servicio de Cardiología, Hospital Universitario Virgen de las Nieves, Granada, Spain.; Instituto de Investigación Biosanitaria de Granada IBS, Granada, Spain., Díaz-Agustín A; Instituto de Química Médica (IQM), Consejo Superior de Investigaciones Científicas (CSIC), 28006 Madrid, Spain., de Benito FM; Centro Nacional de Investigaciones Cardiovasculares (CNIC), 28029 Madrid, Spain.; CIBER de Enfermedades Cardiovasculares (CIBERCV), Madrid, Spain., Santiago SA; Servicio de Dermatología Hospital Universitario Virgen de las Nieves.; Instituto de Investigación Biosanitaria de Granada IBS, Granada, Spain., Braza-Boils A; Unit of Inherited Cardiomyopathies and Sudden Death (CAFAMUSME), Health Research Institute La Fe, La Fe Hospital, Valencia, Spain.; Cardiology Department, Hospital Universitario y Politécnico La Fe, Valencia, Spain., Martín-Martínez M; Instituto de Química Médica (IQM), Consejo Superior de Investigaciones Científicas (CSIC), 28006 Madrid, Spain., Gutierrez-Rodríguez M; Instituto de Química Médica (IQM), Consejo Superior de Investigaciones Científicas (CSIC), 28006 Madrid, Spain., Bernal JA; Centro Nacional de Investigaciones Cardiovasculares (CNIC), 28029 Madrid, Spain.; CIBER de Enfermedades Cardiovasculares (CIBERCV), Madrid, Spain., Zorio E; CIBER de Enfermedades Cardiovasculares (CIBERCV), Madrid, Spain.; Unit of Inherited Cardiomyopathies and Sudden Death (CAFAMUSME), Health Research Institute La Fe, La Fe Hospital, Valencia, Spain.; Cardiology Department, Hospital Universitario y Politécnico La Fe, Valencia, Spain., Jiménez-Jaimez J; Servicio de Cardiología, Hospital Universitario Virgen de las Nieves, Granada, Spain.; Instituto de Investigación Biosanitaria de Granada IBS, Granada, Spain., Jalife J; Centro Nacional de Investigaciones Cardiovasculares (CNIC), 28029 Madrid, Spain.; CIBER de Enfermedades Cardiovasculares (CIBERCV), Madrid, Spain.; Departments of Medicine and Molecular & Integrative Physiology, University of Michigan, Ann Arbor, MI, USA.
Jazyk: angličtina
Zdroj: BioRxiv : the preprint server for biology [bioRxiv] 2023 Jun 08. Date of Electronic Publication: 2023 Jun 08.
DOI: 10.1101/2023.06.07.544151
Abstrakt: Background: Andersen-Tawil Syndrome Type 1 (ATS1) is a rare heritable disease caused by mutations in the strong inwardly rectifying K + channel Kir2.1. The extracellular Cys122-to-Cys154 disulfide bond in the Kir2.1 channel structure is crucial for proper folding, but has not been associated with correct channel function at the membrane. We tested whether a human mutation at the Cys122-to-Cys154 disulfide bridge leads to Kir2.1 channel dysfunction and arrhythmias by reorganizing the overall Kir2.1 channel structure and destabilizing the open state of the channel.
Methods and Results: We identified a Kir2.1 loss-of-function mutation in Cys122 (c.366 A>T; p.Cys122Tyr) in a family with ATS1. To study the consequences of this mutation on Kir2.1 function we generated a cardiac specific mouse model expressing the Kir2.1 C122Y mutation. Kir2.1 C122Y animals recapitulated the abnormal ECG features of ATS1, like QT prolongation, conduction defects, and increased arrhythmia susceptibility. Kir2.1 C122Y mouse cardiomyocytes showed significantly reduced inward rectifier K + (I K1 ) and inward Na + (I Na ) current densities independently of normal trafficking ability and localization at the sarcolemma and the sarcoplasmic reticulum. Kir2.1 C122Y formed heterotetramers with wildtype (WT) subunits. However, molecular dynamic modeling predicted that the Cys122-to-Cys154 disulfide-bond break induced by the C122Y mutation provoked a conformational change over the 2000 ns simulation, characterized by larger loss of the hydrogen bonds between Kir2.1 and phosphatidylinositol-4,5-bisphosphate (PIP 2 ) than WT. Therefore, consistent with the inability of Kir2.1 C122Y channels to bind directly to PIP 2 in bioluminescence resonance energy transfer experiments, the PIP 2 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 PIP 2 concentrations.
Conclusion: The extracellular Cys122-to-Cys154 disulfide bond in the tridimensional Kir2.1 channel structure is essential to channel function. We demonstrated that ATS1 mutations that break disulfide bonds in the extracellular domain disrupt PIP 2 -dependent regulation, leading to channel dysfunction and life-threatening arrhythmias.
Databáze: MEDLINE
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