Targeted deletion of kcne2 impairs ventricular repolarization via disruption of I K,slow1 and I to,f
| Autor: | David J. Christini, Fadi G. Akar, Peter A. Goldstein, Torsten K. Roepke, Kerry Purtell, Geoffrey W. Abbott, Nick Peters, Andrianos Kontogeorgis, Daniel J. Lerner, Xianghua Xu, Jeffrey B. Young, David E. Gutstein, Christopher Ovanez |
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| Rok vydání: | 2008 |
| Předmět: |
Methyl Ethers
medicine.medical_specialty Heart Ventricles Long QT syndrome Biochemistry Research Communications Ventricular action potential Kv1.5 Potassium Channel Mice Sevoflurane Heart Conduction System Internal medicine Genetics medicine Animals Humans Immunoprecipitation Repolarization Molecular Biology Sequence Deletion G alpha subunit Muscle Cells biology Wild type KCNE2 medicine.disease Mice Mutant Strains Potassium channel Long QT Syndrome Shal Potassium Channels Endocrinology Potassium Channels Voltage-Gated Anesthetics Inhalation cardiovascular system biology.protein Electrical conduction system of the heart Biotechnology |
| Zdroj: | The FASEB Journal. 22:3648-3660 |
| ISSN: | 1530-6860 0892-6638 |
| DOI: | 10.1096/fj.08-110171 |
| Popis: | Mutations in human KCNE2, which encodes the MiRP1 potassium channel ancillary subunit, associate with long QT syndrome (LQTS), a defect in ventricular repolarization. The precise cardiac role of MiRP1 remains controversial, in part, because it has marked functional promiscuity in vitro. Here, we disrupted the murine kcne2 gene to define the role of MiRP1 in murine ventricles. kcne2 disruption prolonged ventricular action potential duration (APD), suggestive of reduced repolarization capacity. Accordingly, kcne2 (−/−) ventricles exhibited a 50% reduction in IK,slow1, generated by Kv1.5—a previously unknown partner for MiRP1. Ito,f, generated by Kv4 α subunits, was also diminished, by ∼25%. Ventricular MiRP1 protein coimmunoprecipitated with native Kv1.5 and Kv4.2 but not Kv1.4 or Kv4.3. Unexpectedly, kcne2 (−/−) ventricular membrane fractions exhibited 50% less mature Kv1.5 protein than wild type, and disruption of Kv1.5 trafficking to the intercalated discs. Consistent with the reduction in ventricular K+ currents and prolonged ventricular APD, kcne2 deletion lengthened the QTc under sevoflurane anesthesia. Thus, targeted disruption of kcne2 has revealed a novel cardiac partner for MiRP1, a novel role for MiRPs in α subunit targeting in vivo, and a role for MiRP1 in murine ventricular repolarization with parallels to that proposed for the human heart.—Roepke, T. K., Kontogeorgis, A., Ovanez, C., Xu, X., Young, J. B., Purtell, K., Goldstein, P. A., Christini, D. J., Peters, N. S., Akar, F. G., Gutstein, D. E., Lerner, D. J., Abbott, G. W. Targeted deletion of kcne2 impairs ventricular repolarization via disruption of IK,slow1 and Ito,f. |
| Databáze: | OpenAIRE |
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