TY - JOUR
T1 - Caveolin-3 suppresses late sodium current by inhibiting nNOS-dependent S-nitrosylation of SCN5A
AU - Cheng, Jianding
AU - Valdivia, Carmen R.
AU - Vaidyanathan, Ravi
AU - Balijepalli, Ravi C.
AU - Ackerman, Michael J.
AU - Makielski, Jonathan C.
N1 - Funding Information:
This work was supported by the University of Wisconsin Cellular and Molecular Arrhythmia Research Program (J.C.M.), grant HL71092 (J.C.M.) from the National Institutes of Health, USA, grant R01HL105713 (R.C.B) from the National Institute of Health and grants 30973367 & 81172901 (J.C.) from the National Natural Science Foundation of China.
PY - 2013/8
Y1 - 2013/8
N2 - Aims: Mutations in CAV3-encoding caveolin-3 (Cav3) have been implicated in type 9 long QT syndrome (LQT9) and sudden infant death syndrome (SIDS). When co-expressed with SCN5A-encoded cardiac sodium channels these mutations increased late sodium current (INa) but the mechanism was unclear. The present study was designed to address the mechanism by which the LQT9-causing mutant Cav3-F97C affects the function of caveolar SCN5A. Methods and results: HEK-293 cells expressing SCN5A and LQT9 mutation Cav3-F97C resulted in a 2-fold increase in late INa compared to Cav3-WT. This increase was reversed by the neural nitric oxide synthase (nNOS) inhibitor L-NMMA. Based on these findings, we hypothesized that an nNOS complex mediated the effect of Cav3 on SCN5A. A SCN5A macromolecular complex was established in HEK-293 cells by transiently expressing SCN5A, α1-syntrophin (SNTA1), nNOS, and Cav3. Compared with Cav3-WT, Cav3-F97C produced significantly larger peak INa amplitudes, and showed 3.3-fold increase in the late INa associated with increased S-nitrosylation of SCN5A. L-NMMA reversed both the Cav3-F97C induced increase in late and peak INa and decreased S-nitrosylation of SCN5A. Overexpression of Cav3-F97C in adult rat cardiomyocytes caused a significant increase in late INa compared to Cav3-WT, and prolonged the action potential duration (APD90) in a nNOS-dependent manner. Conclusions: Cav3 is identified as an important negative regulator for cardiac late INa via nNOS dependent direct S-nitrosylation of SCN5A. This provides a molecular mechanism for how Cav3 mutations increase late INa to cause LQT9. This article is part of a Special Issue entitled "Na+ Regulation in Cardiac Myocytes".
AB - Aims: Mutations in CAV3-encoding caveolin-3 (Cav3) have been implicated in type 9 long QT syndrome (LQT9) and sudden infant death syndrome (SIDS). When co-expressed with SCN5A-encoded cardiac sodium channels these mutations increased late sodium current (INa) but the mechanism was unclear. The present study was designed to address the mechanism by which the LQT9-causing mutant Cav3-F97C affects the function of caveolar SCN5A. Methods and results: HEK-293 cells expressing SCN5A and LQT9 mutation Cav3-F97C resulted in a 2-fold increase in late INa compared to Cav3-WT. This increase was reversed by the neural nitric oxide synthase (nNOS) inhibitor L-NMMA. Based on these findings, we hypothesized that an nNOS complex mediated the effect of Cav3 on SCN5A. A SCN5A macromolecular complex was established in HEK-293 cells by transiently expressing SCN5A, α1-syntrophin (SNTA1), nNOS, and Cav3. Compared with Cav3-WT, Cav3-F97C produced significantly larger peak INa amplitudes, and showed 3.3-fold increase in the late INa associated with increased S-nitrosylation of SCN5A. L-NMMA reversed both the Cav3-F97C induced increase in late and peak INa and decreased S-nitrosylation of SCN5A. Overexpression of Cav3-F97C in adult rat cardiomyocytes caused a significant increase in late INa compared to Cav3-WT, and prolonged the action potential duration (APD90) in a nNOS-dependent manner. Conclusions: Cav3 is identified as an important negative regulator for cardiac late INa via nNOS dependent direct S-nitrosylation of SCN5A. This provides a molecular mechanism for how Cav3 mutations increase late INa to cause LQT9. This article is part of a Special Issue entitled "Na+ Regulation in Cardiac Myocytes".
KW - Caveolin-3
KW - LQT9
KW - Long QT syndrome
KW - Nitric oxide synthase
KW - Sodium current
KW - Sudden infant death syndrome
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U2 - 10.1016/j.yjmcc.2013.03.013
DO - 10.1016/j.yjmcc.2013.03.013
M3 - Article
C2 - 23541953
AN - SCOPUS:84880332939
VL - 61
SP - 102
EP - 110
JO - Journal of Molecular and Cellular Cardiology
JF - Journal of Molecular and Cellular Cardiology
SN - 0022-2828
ER -