title: Connexins: substrates and regulators of autophagy.
abstract: Connexins mediate intercellular communication by assembling into hexameric channel complexes that act as hemichannels and gap junction channels. Most connexins are characterized by a very rapid turn-over in a variety of cell systems. The regulation of connexin turn-over by phosphorylation and ubiquitination events has been well documented. Moreover, different pathways have been implicated in connexin degradation, including proteasomal and lysosomal-based pathways. Only recently, autophagy emerged as an important connexin-degradation pathway for different connexin isoforms. As such, conditions well known to induce autophagy have an immediate impact on the connexin-expression levels. This is not only limited to experimental conditions but also several pathophysiological conditions associated with autophagy (dys)function affect connexin levels and their presence at the cell surface as gap junctions. Finally, connexins are not only substrates of autophagy but also emerge as regulators of the autophagy process. In particular, several connexin isoforms appear to recruit pre-autophagosomal autophagy-related proteins, including Atg16 and PI3K-complex components, to the plasma membrane, thereby limiting their availability and capacity for regulating autophagy.
authors.affiliation: KU Leuven, Laboratory of Molecular and Cellular Signaling, Department Cellular and Molecular Medicine, Campus Gasthuisberg O/N-I bus 802, Herestraat 49, B-3000, Leuven, Belgium.
authors.forename: Jegan
authors.initials: J
authors.lastname: Iyyathurai
authors.affiliation: KU Leuven, Laboratory for Membrane Trafficking, Department of Human Genetics, and VIB-Center for the Biology of Disease, Campus Gasthuisberg, O/N-IV, 7.159, Herestraat 49, 3000, Leuven, Belgium.
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Decuypere
authors.affiliation: Ghent University, Physiology Group, Department of Basic Medical Sciences, 9000, Ghent, Belgium.
authors.forename: Luc
authors.initials: L
authors.lastname: Leybaert
authors.affiliation: KU Leuven, Laboratory of Molecular and Cellular Signaling, Department Cellular and Molecular Medicine, Campus Gasthuisberg O/N-I bus 802, Herestraat 49, B-3000, Leuven, Belgium.
authors.forename: Catheleyne
authors.initials: C
authors.lastname: D'hondt
authors.affiliation: KU Leuven, Laboratory of Molecular and Cellular Signaling, Department Cellular and Molecular Medicine, Campus Gasthuisberg O/N-I bus 802, Herestraat 49, B-3000, Leuven, Belgium. geert.bultynck@med.kuleuven.be.
authors.forename: Geert
authors.initials: G
authors.lastname: Bultynck
mesh_terms: D000818:Animals; D001343:Autophagy; D017630:Connexins / Q000378:metabolism*; D006801:Humans; D008247:Lysosomes / Q000378:metabolism; D008954:Models, Biological; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism; D059748:Proteolysis
chemical_list: D017630:Connexins; D046988:Proteasome Endopeptidase Complex
keywords: Autophagy; Connexins; Degradation; Regulation