Academic Journal
Dantrolene rescues aberrant N-terminus intersubunit interactions in mutant pro-arrhythmic cardiac ryanodine receptors
| العنوان: | Dantrolene rescues aberrant N-terminus intersubunit interactions in mutant pro-arrhythmic cardiac ryanodine receptors |
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| المؤلفون: | Seidel, Monika, Lowri Thomas, N., Williams, Alan J., Anthony Lai, F., Zissimopoulos, Spyros |
| بيانات النشر: | Oxford University Press |
| سنة النشر: | 2015 |
| المجموعة: | HighWire Press (Stanford University) |
| مصطلحات موضوعية: | Ion channels and arrhythmias |
| الوصف: | Aims The ryanodine receptor (RyR2) is an intracellular Ca2+ release channel essential for cardiac excitation–contraction coupling. Abnormal RyR2 channel function results in the generation of arrhythmias and sudden cardiac death. The present study was undertaken to investigate the mechanistic basis of RyR2 dysfunction in inherited arrhythmogenic cardiac disease. Methods and results We present several lines of complementary evidence, indicating that the arrhythmia-associated L433P mutation disrupts RyR2 N-terminus self-association. A combination of yeast two-hybrid, co-immunoprecipitation, and chemical cross-linking assays collectively demonstrate that a RyR2 N-terminal fragment carrying the L433P mutation displays substantially reduced self-interaction compared with wild type. Moreover, sucrose density gradient centrifugation reveals that the L433P mutation impairs tetramerization of the full-length channel. [3H]Ryanodine-binding assays demonstrate that disrupted N-terminal intersubunit interactions within RyR2L433P confer an altered sensitivity to Ca2+ activation. Calcium imaging of RyR2L433P-expressing cells reveals substantially prolonged Ca2+ transients and reduced Ca2+ store content indicating defective channel closure. Importantly, dantrolene treatment reverses the L433P mutation-induced impairment and restores channel function. Conclusion The N-terminus domain constitutes an important structural determinant for the functional oligomerization of RyR2. Our findings are consistent with defective N-terminus self-association as a molecular mechanism underlying RyR2 channel deregulation in inherited arrhythmogenic cardiac disease. Significantly, the therapeutic action of dantrolene may occur via the restoration of normal RyR2 N-terminal intersubunit interactions. |
| نوع الوثيقة: | text |
| وصف الملف: | text/html |
| اللغة: | English |
| Relation: | http://cardiovascres.oxfordjournals.org/cgi/content/short/105/1/118; http://dx.doi.org/10.1093/cvr/cvu240 |
| DOI: | 10.1093/cvr/cvu240 |
| الاتاحة: | http://cardiovascres.oxfordjournals.org/cgi/content/short/105/1/118 https://doi.org/10.1093/cvr/cvu240 |
| Rights: | Copyright (C) 2015, European Society of Cardiology |
| رقم الانضمام: | edsbas.BF130639 |
| قاعدة البيانات: | BASE |
| DOI: | 10.1093/cvr/cvu240 |
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