The anchoring protein SAP97 retains Kv1.5 channels in the plasma membrane of cardiac myocytes
| Autor: | Joëlle Abi-Char, Roger Vranckx, Stéphane N. Hatem, Alain Coulombe, Elise Balse, Nathalie Neyroud, Said El-Haou |
|---|---|
| Přispěvatelé: | Génétique, pharmacologie et physiopathologie des maladies cardiovasculaires [Paris], Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU), Unité de Recherche sur les Maladies Cardiovasculaires, du Métabolisme et de la Nutrition = Institute of cardiometabolism and nutrition (ICAN), Université Pierre et Marie Curie - Paris 6 (UPMC)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Institut National de la Santé et de la Recherche Médicale (INSERM)-CHU Pitié-Salpêtrière [AP-HP], Sorbonne Université (SU)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU), Génétique, pharmacologie et physiopathologie des maladies cardiovasculaires, Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de la Santé et de la Recherche Médicale (INSERM), U 460, Institut National de la Santé et de la Recherche Médicale (INSERM), Génétique, pharmacologie et physiopathologie des maladies cardiovasculaires [CHU Pitié-Salpétriêre], Institut National de la Santé et de la Recherche Médicale (INSERM)-CHU Pitié-Salpêtrière [AP-HP], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU), Unité de Recherche sur les Maladies Cardiovasculaires, du Métabolisme et de la Nutrition = Research Unit on Cardiovascular and Metabolic Diseases (ICAN), Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU)-Sorbonne Université (SU), Mécanismes, pathogénies et thérapeutiques expérimentales de remodelage |
| Rok vydání: | 2008 |
| Předmět: |
Patch-Clamp Techniques
Time Factors Physiology MESH: Myocytes Cardiac MESH: Cricetinae MESH: Animals Newborn Membrane Potentials Discs Large Homolog 1 Protein 0302 clinical medicine MESH: Cricetulus MESH: Genetic Vectors MESH: Potassium Channel Blockers Cricetinae Myocyte MESH: Animals Myocytes Cardiac 4-Aminopyridine Cells Cultured 0303 health sciences MESH: Adenoviridae Immunohistochemistry Potassium channel Protein Transport Membrane Biochemistry MESH: 4-Aminopyridine MESH: Membrane Proteins Cardiology and Cardiovascular Medicine MESH: Cells Cultured Fluorescence Recovery After Photobleaching MESH: Protein Transport Guanylate kinase MESH: Rats Recombinant Fusion Proteins Genetic Vectors CHO Cells Biology Transfection Adenoviridae 03 medical and health sciences Kv1.5 Potassium Channel Cricetulus [SDV.MHEP.CSC]Life Sciences [q-bio]/Human health and pathology/Cardiology and cardiovascular system MESH: CHO Cells Physiology (medical) MESH: Patch-Clamp Techniques MESH: Recombinant Fusion Proteins Potassium Channel Blockers MESH: Membrane Potentials Animals Rats Wistar Ion channel 030304 developmental biology MESH: Adaptor Proteins Signal Transducing MESH: Kv1.5 Potassium Channel Adaptor Proteins Signal Transducing MESH: Transfection MESH: Time Factors Cell Membrane Fluorescence recovery after photobleaching Membrane Proteins MESH: Immunohistochemistry MESH: Rats Wistar Rats Membrane protein Animals Newborn MESH: Potassium Biophysics Potassium Membrane channel 030217 neurology & neurosurgery MESH: Fluorescence Recovery After Photobleaching MESH: Cell Membrane |
| Zdroj: | AJP-Heart and Circulatory Physiology AJP-Heart and Circulatory Physiology, American Physiological Society, 2008, 294 (4), pp.H1851-H1861. ⟨10.1152/ajpheart.01045.2007⟩ AJP-Heart and Circulatory Physiology, 2008, 294 (4), pp.H1851-H1861. ⟨10.1152/ajpheart.01045.2007⟩ |
| ISSN: | 0363-6135 1522-1539 |
| DOI: | 10.1152/ajpheart.01045.2007⟩ |
| Popis: | Membrane- associated guanylate kinase proteins (MAGUKs) are important determinants of localization and organization of ion channels into specific plasma membrane domains. However, their exact role in channel function and cardiac excitability is not known. We examined the effect of synapse-associated protein 97 (SAP97), a MAGUK abundantly expressed in the heart, on the function and localization of Kv1.5 subunits in cardiac myocytes. Recombinant SAP97 or Kv1.5 subunits tagged with green fluorescent protein (GFP) were overexpressed in rat neonatal cardiac myocytes and in Chinese hamster ovary (CHO) cells from adenoviral or plasmidic vectors. Immunocytochemistry, fluorescence recovery after photobleaching, and patch-clamp techniques were used to study the effects of SAP97 on the localization, mobility, and function of Kv1.5 subunits. Adenovirus-mediated SAP97 overexpression in cardiac myocytes resulted in the clustering of endogenous Kv1.5 subunits at myocyte-myocyte contacts and an increase in both the maintained component of the outward K+current, IKur(5.64 ± 0.57 pA/pF in SAP97 myocytes vs. 3.23 ± 0.43 pA/pF in controls) and the number of 4-aminopyridine-sensitive potassium channels in cell-attached membrane patches. In live myocytes, GFP-Kv1.5 subunits were mobile and organized in clusters at the basal plasma membrane, whereas SAP97 overexpression reduced their mobility. In CHO cells, Kv1.5 channels were diffusely distributed throughout the cell body and freely mobile. When coexpressed with SAP97, Kv subunits were organized in plaquelike clusters and poorly mobile. In conclusion, SAP97 regulates the K+current in cardiac myocytes by retaining and immobilizing Kv1.5 subunits in the plasma membrane. This new regulatory mechanism may contribute to the targeting of Kv channels in cardiac myocytes. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|