Tania Martins-Marques1,2,3, Steve Catarino1,2,3, Alexandre Gonçalves4, Daniela Miranda-Silva4, Lino Gonçalves3, Pedro Antunes1,3,5, Gonçalo Coutinho1,3,5, Adelino Leite Moreira4, Inês Falcão Pires4, Henrique Girão1,2,3. 1. From the Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine (T.M.-M., S.C., L.C., P.A., G.C., H.G.), University of Coimbra, Portugal. 2. Center for Innovative Biomedicine and Biotechnology (T.M.-M., S.C., H.G.), University of Coimbra, Portugal. 3. Clinical Academic Centre of Coimbra, CACC, Portugal (T.M-M., S.C., L.G., P.A., G.C., H.G.). 4. Department of Surgery and Physiology & Cardiovascular Research Centre, Faculty of Medicine, University of Porto, Portugal (A.G., D.M.S., A.L.M., I.F.P.). 5. Cardiothoracic Surgery (P.A., G.C.), Coimbra Hospital and University Centre, Portugal.
Abstract
RATIONALE: Efficient communication between heart cells is vital to ensure the anisotropic propagation of electrical impulses, a function mainly accomplished by gap junctions (GJ) composed of Cx43 (connexin 43). Although the molecular mechanisms remain unclear, altered distribution and function of gap junctions have been associated with acute myocardial infarction and heart failure. OBJECTIVE: A recent proteomic study from our laboratory identified EHD1 (Eps15 [endocytic adaptor epidermal growth factor receptor substrate 15] homology domain-containing protein 1) as a novel interactor of Cx43 in the heart. METHODS AND RESULTS: In the present work, we demonstrate that knockdown of EHD1 impaired the internalization of Cx43, preserving gap junction-intercellular coupling in cardiomyocytes. Interaction of Cx43 with EHD1 was mediated by Eps15 and promoted by phosphorylation and ubiquitination of Cx43. Overexpression of wild-type EHD1 accelerated internalization of Cx43 and exacerbated ischemia-induced lateralization of Cx43 in isolated adult cardiomyocytes. In addition, we show that EHDs associate with Cx43 in human and murine failing hearts. CONCLUSIONS: Overall, we identified EHDs as novel regulators of endocytic trafficking of Cx43, participating in the pathological remodeling of gap junctions, paving the way to innovative therapeutic strategies aiming at preserving intercellular communication in the heart.
RATIONALE: Efficient communication between heart cells is vital to ensure the anisotropic propagation of electrical impulses, a function mainly accomplished by gap junctions (GJ) composed of Cx43 (connexin 43). Although the molecular mechanisms remain unclear, altered distribution and function of gap junctions have been associated with acute myocardial infarction and heart failure. OBJECTIVE: A recent proteomic study from our laboratory identified EHD1 (Eps15 [endocytic adaptor epidermal growth factor receptor substrate 15] homology domain-containing protein 1) as a novel interactor of Cx43 in the heart. METHODS AND RESULTS: In the present work, we demonstrate that knockdown of EHD1 impaired the internalization of Cx43, preserving gap junction-intercellular coupling in cardiomyocytes. Interaction of Cx43 with EHD1 was mediated by Eps15 and promoted by phosphorylation and ubiquitination of Cx43. Overexpression of wild-type EHD1 accelerated internalization of Cx43 and exacerbated ischemia-induced lateralization of Cx43 in isolated adult cardiomyocytes. In addition, we show that EHDs associate with Cx43 in human and murine failing hearts. CONCLUSIONS: Overall, we identified EHDs as novel regulators of endocytic trafficking of Cx43, participating in the pathological remodeling of gap junctions, paving the way to innovative therapeutic strategies aiming at preserving intercellular communication in the heart.
Entities:
Keywords:
connexin43; gap junctions; heart failure; myocardial infarction; ubiquitination
Authors: Olga M Rusiecka; Jade Montgomery; Sandrine Morel; Daniela Batista-Almeida; Raf Van Campenhout; Mathieu Vinken; Henrique Girao; Brenda R Kwak Journal: Biomolecules Date: 2020-08-23