title: ATG5 defines a phagophore domain connected to the endoplasmic reticulum during autophagosome formation in plants.
abstract: Autophagosomes are the organelles responsible for macroautophagy and arise, in yeast and animals, from the sealing of a cup-shaped double-membrane precursor, the phagophore. How the phagophore is generated and grows into a sealed autophagosome is still not clear in detail, and unknown in plants. This is due, in part, to the scarcity of structurally informative, real-time imaging data of the required protein machinery at the phagophore formation site. Here we find that in intact living Arabidopsis tissue, autophagy-related protein ATG5, which is essential for autophagosome formation, is present at the phagophore site from early, sub-resolution stages and later defines a torus-shaped structure on a flat cisternal early phagophore. Movement and expansion of this structure are accompanied by the underlying endoplasmic reticulum, suggesting tight connections between the two compartments. Detailed real-time and 3D imaging of the growing phagophore are leveraged to propose a model for autophagosome formation in plants.
authors.affiliation: Laboratoire Dynamique de la Compartimentation Cellulaire, CNRS UPR2355, Institut des Sciences du Végétal, Centre de Recherche de Gif (FRC3115), Saclay Plant Sciences, 91198 Gif-sur-Yvette, France.
authors.forename: Romain
authors.initials: R
authors.lastname: Le Bars
authors.affiliation: Laboratoire Dynamique de la Compartimentation Cellulaire, CNRS UPR2355, Institut des Sciences du Végétal, Centre de Recherche de Gif (FRC3115), Saclay Plant Sciences, 91198 Gif-sur-Yvette, France.
authors.forename: Jessica
authors.initials: J
authors.lastname: Marion
authors.affiliation: 1] Laboratoire Dynamique de la Compartimentation Cellulaire, CNRS UPR2355, Institut des Sciences du Végétal, Centre de Recherche de Gif (FRC3115), Saclay Plant Sciences, 91198 Gif-sur-Yvette, France [2] Pôle de Biologie Cellulaire, Imagif, Centre de Recherche de Gif, (FRC3115), Saclay Plant Sciences, CNRS, 91198 Gif-sur-Yvette, France.
authors.forename: Rémi
authors.initials: R
authors.lastname: Le Borgne
authors.affiliation: 1] Laboratoire Dynamique de la Compartimentation Cellulaire, CNRS UPR2355, Institut des Sciences du Végétal, Centre de Recherche de Gif (FRC3115), Saclay Plant Sciences, 91198 Gif-sur-Yvette, France [2] Pôle de Biologie Cellulaire, Imagif, Centre de Recherche de Gif, (FRC3115), Saclay Plant Sciences, CNRS, 91198 Gif-sur-Yvette, France.
authors.forename: Béatrice
authors.initials: B
authors.lastname: Satiat-Jeunemaitre
authors.affiliation: 1] Laboratoire Dynamique de la Compartimentation Cellulaire, CNRS UPR2355, Institut des Sciences du Végétal, Centre de Recherche de Gif (FRC3115), Saclay Plant Sciences, 91198 Gif-sur-Yvette, France [2] UFR Sciences et Technologie, Université Paris-Est Créteil Val de Marne (UPEC), 61 av. Général de Gaulle, 94010 Créteil, France.
authors.forename: Michele Wolfe
authors.initials: MW
authors.lastname: Bianchi
mesh_terms: D017360:Arabidopsis / Q000378:metabolism / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000378:metabolism*; D001343:Autophagy / Q000502:physiology*; D000071187:Autophagy-Related Protein 5; D004721:Endoplasmic Reticulum / Q000378:metabolism*; D021621:Imaging, Three-Dimensional; D008856:Microscopy, Fluorescence; D010588:Phagosomes / Q000378:metabolism / Q000502:physiology*; D010744:Phosphoric Monoester Hydrolases / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; D000071187:Autophagy-Related Protein 5; C518662:Atg5 protein, Arabidopsis; D010744:Phosphoric Monoester Hydrolases