title: A unique hairpin-type tail-anchored SNARE starts to solve a long-time puzzle.
abstract: Macroautophagy mediates recycling of intracellular material by a multistep pathway, ultimately leading to the fusion of closed double-membrane structures, called autophagosomes, with the lysosome. This event ensures the degradation of the autophagosome content by lysosomal proteases followed by the release of macromolecules by permeases and, thus, it accomplishes the purpose of macroautophagy (hereafter referred to as autophagy). Because fusion of unclosed autophagosomes (i.e., phagophores) with the lysosome would fail to degrade the autophagic cargo, this critical step has to be tightly controlled. Yet, until recently, little was known about the regulation of this event and the factors orchestrating it. A punctum in this issue highlights the recent paper by Noboru Mizushima and his collaborators that answered the question of how premature fusion of phagophores with the lysosome is prevented prior to completion of autophagosome closure.
authors.affiliation: Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA.
authors.forename: Amélie
authors.initials: A
authors.lastname: Bernard
authors.forename: Hana
authors.initials: H
authors.lastname: Popelka
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Klionsky
mesh_terms: D000818:Animals; D001343:Autophagy; D006801:Humans; D008247:Lysosomes / Q000378:metabolism; D010588:Phagosomes / Q000378:metabolism; D017434:Protein Structure, Tertiary; D050765:Qa-SNARE Proteins / Q000378:metabolism; D050600:SNARE Proteins / Q000737:chemistry* / Q000378:metabolism*
chemical_list: D050765:Qa-SNARE Proteins; D050600:SNARE Proteins
keywords: SNARE; autophagosome; fusion; glycine zipper; lysosome