title: To beat or not to beat: degradation of Cx43 imposes the heart rhythm.
abstract: The main function of the heart is to pump blood to the different parts of the organism, a task that is efficiently accomplished through proper electric and metabolic coupling between cardiac cells, ensured by gap junctions (GJ). Cardiomyocytes are the major cell population in the heart, and as cells with low mitotic activity, are highly dependent upon mechanisms of protein degradation. In the heart, both the ubiquitin-proteasome system (UPS) and autophagy participate in the fine-tune regulation of cardiac remodelling and function, either in physiological or pathological conditions. Indeed, besides controlling cardiac signalling pathways, UPS and autophagy have been implicated in the turnover of several myocardial proteins. Degradation of Cx43, the major ventricular GJ protein, has been associated to up-regulation of autophagy at the onset of heart ischemia and ischemia/reperfusion (I/R), which can have profound implications upon cardiac function. In this review, we present recent studies devoted to the involvement of autophagy and UPS in heart homoeostasis, with a particular focus on GJ.
authors.affiliation: *Centre of Ophthalmology and Vision Sciences, Institute of Biomedical Imaging and Life Sciences (IBILI), Faculty of Medicine, University of Coimbra, Azinhaga de Sta Comba, 3000-354 Coimbra, Portugal.
authors.forename: Tânia
authors.initials: T
authors.lastname: Martins-Marques
authors.affiliation: *Centre of Ophthalmology and Vision Sciences, Institute of Biomedical Imaging and Life Sciences (IBILI), Faculty of Medicine, University of Coimbra, Azinhaga de Sta Comba, 3000-354 Coimbra, Portugal.
authors.forename: Steve
authors.initials: S
authors.lastname: Catarino
authors.affiliation: *Centre of Ophthalmology and Vision Sciences, Institute of Biomedical Imaging and Life Sciences (IBILI), Faculty of Medicine, University of Coimbra, Azinhaga de Sta Comba, 3000-354 Coimbra, Portugal.
authors.forename: Carla
authors.initials: C
authors.lastname: Marques
authors.affiliation: *Centre of Ophthalmology and Vision Sciences, Institute of Biomedical Imaging and Life Sciences (IBILI), Faculty of Medicine, University of Coimbra, Azinhaga de Sta Comba, 3000-354 Coimbra, Portugal.
authors.forename: Paulo
authors.initials: P
authors.lastname: Pereira
authors.affiliation: *Centre of Ophthalmology and Vision Sciences, Institute of Biomedical Imaging and Life Sciences (IBILI), Faculty of Medicine, University of Coimbra, Azinhaga de Sta Comba, 3000-354 Coimbra, Portugal.
authors.forename: Henrique
authors.initials: H
authors.lastname: Girão
mesh_terms: D064752:Atrial Remodeling / Q000235:genetics / Q000502:physiology; D001343:Autophagy / Q000235:genetics; D018031:Connexin 43 / Q000235:genetics / Q000378:metabolism*; D017629:Gap Junctions / Q000235:genetics / Q000378:metabolism; D006801:Humans; D015428:Myocardial Reperfusion Injury / Q000235:genetics* / Q000503:physiopathology; D032383:Myocytes, Cardiac / Q000378:metabolism* / Q000473:pathology; D059748:Proteolysis; D015398:Signal Transduction; D025801:Ubiquitin / Q000378:metabolism
chemical_list: D018031:Connexin 43; C500216:GJA1 protein, human; D025801:Ubiquitin