Background/aims: The cardiac current IKs is carried by the KCNQ1/KCNE1-channel complex. Genetic aberrations that affect the activity of KCNQ1/KCNE1 can lead to the Long QT Syndrome 1 and 5 and, thereby, to a predisposition to sudden cardiac death. This might be prevented by pharmacological modulation of KCNQ1/KCNE1. The prototypic KCNQ1/KCNE1 activator 4,4'-Diisothiocyanatostilbene-2,2'-disulfonic acid (DIDS) represents a candidate drug. Here, we study the mechanism of DIDS action on KCNQ1/KCNE1.
Methods: Channels were expressed in Xenopus oocytes and iPSC cardiomyocytes. The role of the central S6 region was investigated by alanin-screening of KCNQ1 residues 333-338. DIDS effects were measured by TEVC and MEA.
Results: DIDS-action is influenced by the presence of KCNE1 but not by KCNQ1/KCNE1 stochiometry. V334A produces a significant higher increase in current amplitude, whereas deactivation (slowdown) DIDS-sensitivity is affected by residues 334-338.
Conclusion: We show that the central S6 region serves as a hub for allosteric channel activation by the drug and that DIDS shortens the pseudo QT interval in iPSC cardiomyocytes. The elucidation of the structural and mechanistic underpinnings of the DIDS action on KCNQ1/KCNE1 might allow for a targeted design of DIDS derivatives with improved potency and selectivity.
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http://dx.doi.org/10.33594/000000222 | DOI Listing |
Int J Biol Sci
January 2025
Faculty of Health Sciences, University of Macau, Taipa, Macau.
Ion channels play a crucial role in cardiac functions, and their activities exhibit dynamic changes during heart development. However, the precise function of ion channels in human heart development remains elusive. In this study, we utilized human embryonic stem cells (hESCs) as a model to mimic the process of human embryonic heart development.
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Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, 200241, China.
Virus Res
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Department of Veterinary Medicine, College of Veterinary Medicine, National Chung Hsing University, 145 Xingda Road, Taichung 402, Taiwan.; The iEGG and Animal Biotechnology Center, National Chung Hsing University, 250 Kuo Kuang Road, Taichung 40227, Taiwan. Electronic address:
Coronaviruses (CoVs) are significant animal and human pathogens, characterized by being enveloped RNA viruses with positive-sense single-stranded RNA. The Coronaviridae family encompasses four genera, among which gammacoronaviruses pose a major threat to the poultry industry, which infectious bronchitis virus (IBV) being the most prominent of these threats. Particularly, IBV adversely affects broiler growth and egg production, causing substantial losses.
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Key Laboratory of Bioactive Materials, Ministry of Education, College of Life Sciences, Nankai University, Tianjin 300071, China. Electronic address:
Nat Commun
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Department of Orthopaedics, Shanghai Key Laboratory of Orthopaedic Implant, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
Anion exchanger 3 (AE3) is pivotal in regulating intracellular pH across excitable tissues, yet its structural intricacies and functional dynamics remain underexplored compared to other anion exchangers. This study unveils the structural insights into human AE3, including the cryo-electron microscopy structures for AE3 transmembrane domains (TMD) and a chimera combining AE3 N-terminal domain (NTD) with AE2 TMD (hAE32). Our analyzes reveal a substrate binding site, an NTD-TMD interlock mechanism, and a preference for an outward-facing conformation.
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