Structure-function relationship of Atg12, a ubiquitin-like modifier essential for autophagy.
Takao Hanada,Yoshinori Ohsumi +1 more
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TLDR
It is shown that the carboxyl-terminal region of Atg12 that is predicted to fold into a ubiquitin-like structure is necessary and sufficient for both conjugation and autophagy, which indicates that the domain essential for autophagosome formation resides in the ubiqu itin-fold region.Abstract:
Atg12, a post-translational modifier, is activated and conjugated to Atg5 by a ubiquitin-like conjugation system, though it has no obvious sequence homology to ubiquitin. The Atg12-Atg5 conjugate is essential for autophagy, an intracellular bulk degradation process. Here, we show that the carboxyl-terminal region of Atg12 that is predicted to fold into a ubiquitin-like structure is necessary and sufficient for both conjugation and autophagy, which indicates that the domain essential for autophagy resides in the ubiquitin-fold region. We further show that two hydrophobic residues within the ubiquitin-fold region are important for autophagy: mutation at Y149 affects conjugate formation catalyzed by Atg10, an E2-like enzyme, while mutation at F154 has no effect on Atg12-Atg5 conjugate formation but its hydrophobic nature is essential for autophagy. In response to the F154 mutation, Atg8-PE conjugation, the other ubiquitin-like conjugation in autophagy, is severely reduced and autophagosome formation fails. G...read more
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Dynamics and diversity in autophagy mechanisms: lessons from yeast
TL;DR: The discovery of autophagy in yeast and the genetic tractability of this organism have allowed us to identify genes that are responsible for this process, which has led to the explosive growth of this research field seen today.
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Atg8, a Ubiquitin-like Protein Required for Autophagosome Formation, Mediates Membrane Tethering and Hemifusion
TL;DR: It is shown using an in vitro system that Atg8 mediates the tethering and hemifusion of membranes, which are evoked by the lipidation of the protein and reversibly modulated by the deconjugation enzyme Atg4.
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The Atg12-Atg5 conjugate has a novel E3-like activity for protein lipidation in autophagy.
Takao Hanada,Nobuo N. Noda,Yoshinori Satomi,Yoshinobu Ichimura,Yuko Fujioka,Toshifumi Takao,Fuyuhiko Inagaki,Yoshinori Ohsumi +7 more
TL;DR: Results indicate that the Atg12-Atg5 conjugate is a ubiquitin-protein ligase (E3)-like enzyme for Atg8-PE conjugation reaction, distinctively promoting protein-lipid conjugations.
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The Atg16L Complex Specifies the Site of LC3 Lipidation for Membrane Biogenesis in Autophagy
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Protein turnover via autophagy: implications for metabolism.
TL;DR: This work reviews the current information on the mechanism of autophagy, with a focus on its role in protein metabolism and intracellular homeostasis.
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TL;DR: A new mode of protein lipidation is reported, in which Apg8 is covalently conjugated to phosphatidylethanolamine through an amide bond between the C-terminal glycine and the amino group of phosph atidyleanolamine, mediated by a ubiquitination-like system.
Journal ArticleDOI
A proteomics approach to understanding protein ubiquitination
Junmin Peng,Junmin Peng,Daniel Schwartz,Joshua E. Elias,Carson C. Thoreen,Dongmei Cheng,Gerald T. Marsischky,Jeroen Roelofs,Daniel Finley,Steven P. Gygi +9 more
TL;DR: A proteomics approach to enrich, recover, and identify ubiquitin conjugates from Saccharomyces cerevisiae lysate provides a general tool for the large-scale analysis and characterization of protein ubiquitination.
Journal ArticleDOI
A protein conjugation system essential for autophagy
Noboru Mizushima,Takeshi Noda,Tamotsu Yoshimori,Yae Tanaka,Tomoko Ishii,Michael D. George,Daniel J. Klionsky,Mariko Ohsumi,Yoshinori Ohsumi +8 more
TL;DR: It is shown here that a unique covalent-modification system is essential for autophagy to occur, the first report of a protein unrelated to ubiquitin that uses a ubiquitination-like conjugation system.