title: High-resolution live-cell imaging reveals novel cyclin A2 degradation foci involving autophagy.
abstract: Cyclin A2 is a key player in the regulation of the cell cycle. Its degradation in mid-mitosis relies on the ubiquitin-proteasome system (UPS). Using high-resolution microscopic imaging, we find that cyclin A2 persists beyond metaphase. Indeed, we identify a novel cyclin-A2-containing compartment that forms dynamic foci. Förster (or fluorescence) resonance energy transfer (FRET) and fluorescence lifetime imaging microscopy (FLIM) analyses show that cyclin A2 ubiquitylation takes place predominantly in these foci before spreading throughout the cell. Moreover, inhibition of autophagy in proliferating cells induces the stabilisation of a subset of cyclin A2, whereas induction of autophagy accelerates the degradation of cyclin A2, thus showing that autophagy is a novel regulator of cyclin A2 degradation.
authors.affiliation: Institut de Génétique Moléculaire de Montpellier, CNRS, Université Montpellier 2, Université Montpellier 1, 1919 route de Mende, 34293 Montpellier, France.
authors.forename: Abdelhalim
authors.initials: A
authors.lastname: Loukil
authors.affiliation: Institut de Génétique Moléculaire de Montpellier, CNRS, Université Montpellier 2, Université Montpellier 1, 1919 route de Mende, 34293 Montpellier, France.
authors.forename: Manuela
authors.initials: M
authors.lastname: Zonca
authors.affiliation: Institut de Génétique Moléculaire de Montpellier, CNRS, Université Montpellier 2, Université Montpellier 1, 1919 route de Mende, 34293 Montpellier, France.
authors.forename: Cosette
authors.initials: C
authors.lastname: Rebouissou
authors.affiliation: Centre de Recherche de Biochimie Macromoléculaire, CNRS, Université Montpellier 2, Université Montpellier 1, 1919 route de Mende, 34293 Montpellier, France.
authors.forename: Véronique
authors.initials: V
authors.lastname: Baldin
authors.affiliation: Centre de Recherche de Biochimie Macromoléculaire, CNRS, Université Montpellier 2, Université Montpellier 1, 1919 route de Mende, 34293 Montpellier, France.
authors.forename: Olivier
authors.initials: O
authors.lastname: Coux
authors.affiliation: Centre d'étude d'agents Pathogènes et Biotechnologies pour la Santé, CNRS, Université Montpellier 2, Université Montpellier 1, 1919 route de Mende, 34293 Montpellier, France.
authors.forename: Martine
authors.initials: M
authors.lastname: Biard-Piechaczyk
authors.affiliation: Institut de Génétique Moléculaire de Montpellier, CNRS, Université Montpellier 2, Université Montpellier 1, 1919 route de Mende, 34293 Montpellier, France.
authors.forename: Jean-Marie
authors.initials: JM
authors.lastname: Blanchard
authors.affiliation: Institut de Génétique Moléculaire de Montpellier, CNRS, Université Montpellier 2, Université Montpellier 1, 1919 route de Mende, 34293 Montpellier, France marion.peter@igmm.cnrs.fr.
authors.forename: Marion
authors.initials: M
authors.lastname: Peter
mesh_terms: D001343:Autophagy / Q000502:physiology*; D002450:Cell Communication; D056751:Cyclin A2 / Q000378:metabolism*; D031541:Fluorescence Resonance Energy Transfer / Q000379:methods*; D006801:Humans; D061986:MCF-7 Cells; D008856:Microscopy, Fluorescence / Q000379:methods; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism*; D025801:Ubiquitin / Q000378:metabolism*
chemical_list: C503721:CCNA2 protein, human; D056751:Cyclin A2; D025801:Ubiquitin; D046988:Proteasome Endopeptidase Complex
keywords: Autophagy; Cyclin A2; FLIM; FRET; Mitosis; Ubiquitin-proteasome system