CaMKII Modulates the Cardiac Transient Outward K+ Current through its Association with Kv4 Channels in Non-Caveolar Membrane Rafts
| Autor: | Janire Urrutia, Oscar Casis, Aintzane Alday, Mónica Gallego, Victor Fernández-López, Leyre Echeazarra, Hasna Ahyayauch |
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| Rok vydání: | 2019 |
| Předmět: |
0301 basic medicine
Calmodulin Physiology Population lcsh:Physiology lcsh:Biochemistry 03 medical and health sciences 0302 clinical medicine Western blot Ca2+/calmodulin-dependent protein kinase Caveolae medicine lcsh:QD415-436 education Lipid raft education.field_of_study lcsh:QP1-981 medicine.diagnostic_test biology Chemistry Immunogold labelling Subcellular localization 030104 developmental biology 030220 oncology & carcinogenesis cardiovascular system biology.protein Biophysics |
| Zdroj: | Cellular Physiology and Biochemistry, Vol 54, Iss 1, Pp 27-39 (2020) |
| ISSN: | 1421-9778 1015-8987 |
| DOI: | 10.33594/000000203 |
| Popis: | Background/aims To test whether the physiological regulation of the cardiac Kv4 channels by the Ca2+/calmodulin-dependent protein kinase II (CaMKII) is restricted to lipid rafts and whether the interactions observed in rat cardiomyocytes also occur in the human ventricle. Methods Ventricular myocytes were freshly isolated from Sprague-Dawley rats. Ito was recorded by the whole-cell Patch-Clamp technique. Membrane rafts were isolated by centrifugation in a discontinuous sucrose density gradient. The presence of the proteins of interest was analysed by western blot. Immunogold staining and electron microscopy of heart vibrosections was performed to localize Kv4.2/Kv4.3 and CaMKII proteins. Protein-protein interactions were determined by co-immunoprecipitation experiments in rat and human ventricular mycoytes. Results Patch-Clamp recordings in control conditions and after lipid raft or caveolae disruption show that the CaMKII-Kv4 channel complex must associate in non-caveolar lipid rafts to be functional. Separation in density gradients, co-immunoprecipitation and electron microscopy show that there are two Kv4 channel populations: one located in caveolae, that is CaMKII independent, and another one located in planar membrane rafts, which is bound to CaMKII. Conclusion CaMKII regulates only the Kv4 channel population located in non-caveolar lipid rafts. Thus, the regulation of cardiac Kv4 channels in rat and human ventricle depends on their subcellular localization. |
| Databáze: | OpenAIRE |
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