1
|
Bassetto CAZ, Costa F, Guardiani C, Bezanilla F, Giacomello A. Noncanonical electromechanical coupling paths in cardiac hERG potassium channel. Nat Commun 2023; 14:1110. [PMID: 36849440 PMCID: PMC9971164 DOI: 10.1038/s41467-023-36730-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Accepted: 02/15/2023] [Indexed: 03/01/2023] Open
Abstract
Voltage-gated potassium channels are involved in many physiological processes such as nerve impulse transmission, the heartbeat, and muscle contraction. However, for many of them the molecular determinants of the gating mechanism remain elusive. Here, using a combination of theoretical and experimental approaches, we address this problem focusing on the cardiac hERG potassium channel. Network analysis of molecular dynamics trajectories reveals the presence of a kinematic chain of residues that couples the voltage sensor domain to the pore domain and involves the S4/S1 and S1/S5 subunit interfaces. Mutagenesis experiments confirm the role of these residues and interfaces in the activation and inactivation mechanisms. Our findings demonstrate the presence of an electromechanical transduction path crucial for the non-domain-swapped hERG channel gating that resembles the noncanonical path identified in domain-swapped K+ channels.
Collapse
Affiliation(s)
- Carlos A Z Bassetto
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL, USA
| | - Flavio Costa
- Dipartimento di Ingegneria Meccanica e Aerospaziale, Sapienza Università di Roma, Rome, Italy
| | - Carlo Guardiani
- Dipartimento di Ingegneria Meccanica e Aerospaziale, Sapienza Università di Roma, Rome, Italy
| | - Francisco Bezanilla
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL, USA.
- Institute for Biophysical Dynamics, The University of Chicago, Chicago, IL, USA.
- Centro Interdisciplinario de Neurociencias, Facultad de Ciencias, Universidad de Valparaiso, Valparaiso, Chile.
| | - Alberto Giacomello
- Dipartimento di Ingegneria Meccanica e Aerospaziale, Sapienza Università di Roma, Rome, Italy.
| |
Collapse
|
2
|
Du F, Wang G, Wang D, Su G, Yao G, Zhang W, Su G. Targeted next generation sequencing revealed a novel deletion-frameshift mutation of KCNH2 gene in a Chinese Han family with long QT syndrome: A case report and review of Chinese cases. Medicine (Baltimore) 2020; 99:e19749. [PMID: 32311972 PMCID: PMC7220270 DOI: 10.1097/md.0000000000019749] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
INTRODUCTION Long QT syndrome (LQTS) is electrocardiographically characterized by a prolonged QT interval and manifests predisposition to life-threatening arrhythmia which often leads to sudden cardiac death. Type 2 LQTS (LQT2) is the second most common subtype of LQTS and caused by mutations in KCNH2 gene. Up to date, >900 mutations have been reported to be related to LQT2. However, mutational screening of the KCNH2 gene is still far from completeness. Identification of KCNH2 mutations is particularly important in diagnosis of LQT2 and will gain more insights into the molecular basis for the pathogenesis of LQT2. PATIENT CONCERNS A Chinese Han family with LQTS phenotypes was examined. DIAGNOSIS A novel deletion-frameshift mutation, c.381_408delCAATTTCGAGGTGGTGATGGAGAAGGAC, in exon 3 of KCNH2 gene was identified in a Chinese family with LQTS. On the basis of this finding and clinical manifestations, the final diagnosis of LQT2 was made. INTERVENTIONS Next-generation sequencing (NGS) of DNA samples was performed to detect the mutation in the LQTS-related genes on the proband and her mother, which was confirmed by Sanger sequencing. The proband was then implanted with an implantable cardioverter defibrillator and prescribed metoprolol 47.5 mg per day. OUTCOMES This novel heterozygous mutation results in a frameshift mutation after the 128 residue (Asparagine), which replaced the original 1031 amino acids with 27 novel amino acids (p.N128fsX156). CONCLUSION This novel mutation presumably resulted in a frameshift mutation, p.N128fsX156. Our data expanded the mutation spectrum of KCNH2 gene and facilitated clinic diagnosis and genetic counseling for this family with LQTS.
Collapse
Affiliation(s)
- Fengli Du
- Institute of Translational Medicine, Jinan Central Hospital Affiliated to Shandong University
- Department of Postgraduate, Shandong First Medical University, Jinan, Shandong
| | - Guangxin Wang
- Institute of Translational Medicine, Jinan Central Hospital Affiliated to Shandong University
- Department of Postgraduate, Shandong First Medical University, Jinan, Shandong
| | - Dawei Wang
- Department of Biomedical Sciences, City University of Hong Kong, Hong Kong SAR, China
| | - Guoying Su
- Institute of Translational Medicine, Jinan Central Hospital Affiliated to Shandong University
| | - Guixiang Yao
- Department of Cardiology, Jinan Central Hospital Affiliated to Shandong University, Jinan, Shandong, China
| | - Wei Zhang
- Department of Cardiology, Jinan Central Hospital Affiliated to Shandong University, Jinan, Shandong, China
| | - Guohai Su
- Institute of Translational Medicine, Jinan Central Hospital Affiliated to Shandong University
- Department of Postgraduate, Shandong First Medical University, Jinan, Shandong
| |
Collapse
|
3
|
Chakraborty P, Isser HS, Arava S, Bhatia M, Mandal K, Jahangir A. Unusual Cause of Bidirectional Ventricular Rhythm. JACC Case Rep 2019; 1:21-26. [PMID: 34316734 PMCID: PMC8288602 DOI: 10.1016/j.jaccas.2019.05.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Revised: 05/01/2019] [Accepted: 05/02/2019] [Indexed: 11/06/2022]
Abstract
Bidirectional ventricular tachycardia (BDVT), a rare ventricular arrhythmia, is commonly caused by digitalis toxicity or channelopathies and is rarely caused by aconite toxicity, myocarditis, infarction, or sarcoidosis. This paper describes a patient with BDVT, recurrent syncope, myocardial disarray, and interstitial fibrosis on histology but normal results on echocardiography with variants in the TTN, KCNH2, and GATA4 genes. (Level of Difficulty: Advanced.)
Collapse
Affiliation(s)
- Praloy Chakraborty
- Department of Cardiac Electrophysiology, Toronto General Hospital, Toronto, Ontario, Canada
| | - Hermohander Singh Isser
- Department of Cardiology, Vardhman Mahavir Medical College and Safdarjung Hospital, Delhi, India
| | - Sudheer Arava
- Department of Pathology, All India Institute of Medical Science, New Delhi, India
| | - Mona Bhatia
- Department of Radiology and Imaging, Fortis Escorts Heart Institute, New Delhi, India
| | - Kausik Mandal
- Department of Medical Genetics, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India
| | - Arshad Jahangir
- Aurora Center for Advanced Atrial Fibrillation Therapies, Aurora Cardiovascular Services, Aurora Health Care, Milwaukee, Wisconsin
| |
Collapse
|
4
|
Altomare C, Bartolucci C, Sala L, Bernardi J, Mostacciuolo G, Rocchetti M, Severi S, Zaza A. I
Kr
Impact on Repolarization and Its Variability Assessed by Dynamic Clamp. Circ Arrhythm Electrophysiol 2015; 8:1265-75. [DOI: 10.1161/circep.114.002572] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Accepted: 06/16/2015] [Indexed: 01/23/2023]
Abstract
Background—
Repolarization and its stability are exquisitely sensitive to
I
Kr
features. Information on the relative importance of specific
I
Kr
abnormalities is missing and would assist in the evaluation of arrhythmogenic risk.
Methods and Results—
In single guinea-pig myocytes, endogenous
I
Kr
was replaced by modeled
I
Kr
(m
I
Kr
) by dynamic clamp (DC) at a cycle length of 1 s. m
I
Kr
parameters were systematically modified, and the resulting changes in action potential duration (APD) and its short term variability (SD1) were measured. We observed that (1)
I
Kr
blockade increased SD1 more than expected by its dependency on APD; (2) m
I
Kr
completely reversed APD and SD1 changes caused by
I
Kr
blockade; (3) repolarization was most sensitive to inactivation shifts, which affected APD and SD1 concordantly; (4) activation shifts of the same magnitude had marginal impact on APD, but only when reducing m
I
Kr
, they significantly increased SD1; (5) changes in maximal conductance resulted in a pattern similar to that of activation shifts.
Conclusions—
The largest effect on repolarization and its stability are expected from changes in
I
Kr
inactivation. APD is less sensitive to changes in other
I
Kr
gating parameters, which are better revealed by SD1 changes. SD1 may be more sensitive than APD in detecting
I
Kr
-dependent repolarization abnormalities.
Collapse
Affiliation(s)
- Claudia Altomare
- From the Department of Biotechnologies & Biosciences, University of Milano-Bicocca, Milano (C.A., L.S., J.B., G.M., M.R., A.Z.); and Department of Electrical, Electronic and Information Engineering “Guglielmo Marconi”, University of Bologna, Cesena, Italy (C.B., S.S.)
| | - Chiara Bartolucci
- From the Department of Biotechnologies & Biosciences, University of Milano-Bicocca, Milano (C.A., L.S., J.B., G.M., M.R., A.Z.); and Department of Electrical, Electronic and Information Engineering “Guglielmo Marconi”, University of Bologna, Cesena, Italy (C.B., S.S.)
| | - Luca Sala
- From the Department of Biotechnologies & Biosciences, University of Milano-Bicocca, Milano (C.A., L.S., J.B., G.M., M.R., A.Z.); and Department of Electrical, Electronic and Information Engineering “Guglielmo Marconi”, University of Bologna, Cesena, Italy (C.B., S.S.)
| | - Joyce Bernardi
- From the Department of Biotechnologies & Biosciences, University of Milano-Bicocca, Milano (C.A., L.S., J.B., G.M., M.R., A.Z.); and Department of Electrical, Electronic and Information Engineering “Guglielmo Marconi”, University of Bologna, Cesena, Italy (C.B., S.S.)
| | - Gaspare Mostacciuolo
- From the Department of Biotechnologies & Biosciences, University of Milano-Bicocca, Milano (C.A., L.S., J.B., G.M., M.R., A.Z.); and Department of Electrical, Electronic and Information Engineering “Guglielmo Marconi”, University of Bologna, Cesena, Italy (C.B., S.S.)
| | - Marcella Rocchetti
- From the Department of Biotechnologies & Biosciences, University of Milano-Bicocca, Milano (C.A., L.S., J.B., G.M., M.R., A.Z.); and Department of Electrical, Electronic and Information Engineering “Guglielmo Marconi”, University of Bologna, Cesena, Italy (C.B., S.S.)
| | - Stefano Severi
- From the Department of Biotechnologies & Biosciences, University of Milano-Bicocca, Milano (C.A., L.S., J.B., G.M., M.R., A.Z.); and Department of Electrical, Electronic and Information Engineering “Guglielmo Marconi”, University of Bologna, Cesena, Italy (C.B., S.S.)
| | - Antonio Zaza
- From the Department of Biotechnologies & Biosciences, University of Milano-Bicocca, Milano (C.A., L.S., J.B., G.M., M.R., A.Z.); and Department of Electrical, Electronic and Information Engineering “Guglielmo Marconi”, University of Bologna, Cesena, Italy (C.B., S.S.)
| |
Collapse
|