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Polyubiquitin chain-induced p62 phase separation drives autophagic cargo segregation

Misfolded proteins can be degraded by selective autophagy. The prevailing view is that ubiquitin-tagged misfolded proteins are assembled into aggregates by the scaffold protein p62, and the aggregates are then engulfed and degraded by autophagosomes. Here we report that p62 forms droplets in vivo wh...

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Autores principales: Sun, Daxiao, Wu, Rongbo, Zheng, Jingxiang, Li, Pilong, Yu, Li
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Publishing Group UK 2018
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5939046/
https://www.ncbi.nlm.nih.gov/pubmed/29507397
http://dx.doi.org/10.1038/s41422-018-0017-7
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author Sun, Daxiao
Wu, Rongbo
Zheng, Jingxiang
Li, Pilong
Yu, Li
author_facet Sun, Daxiao
Wu, Rongbo
Zheng, Jingxiang
Li, Pilong
Yu, Li
author_sort Sun, Daxiao
collection PubMed
description Misfolded proteins can be degraded by selective autophagy. The prevailing view is that ubiquitin-tagged misfolded proteins are assembled into aggregates by the scaffold protein p62, and the aggregates are then engulfed and degraded by autophagosomes. Here we report that p62 forms droplets in vivo which have liquid-like properties such as high sphericity, the ability to undergo fusion, and recovery after photobleaching. Recombinant p62 does not undergo phase separation in vitro; however, adding a K63 polyubiquitin chain to p62 induces p62 phase separation, which results in enrichment of high-molecular weight ubiquitin signals in p62 droplets. Mixing recombinant p62 with cytosol from p62(−/−) cells also results in p62 phase separation in a polyubiquitination-dependent manner. Mechanistically, p62 phase separation is dependent on p62 polymerization, the interaction between p62 and ubiquitin, and the valence of the polyubiquitin chain. Moreover, p62 phase separation can be regulated by post-translational modifications such as phosphorylation. Finally, we demonstrate that disease-associated mutations in p62 can affect phase separation. We propose that polyubiquitin chain-induced p62 phase separation drives autophagic cargo concentration and segregation.
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spelling pubmed-59390462018-06-20 Polyubiquitin chain-induced p62 phase separation drives autophagic cargo segregation Sun, Daxiao Wu, Rongbo Zheng, Jingxiang Li, Pilong Yu, Li Cell Res Article Misfolded proteins can be degraded by selective autophagy. The prevailing view is that ubiquitin-tagged misfolded proteins are assembled into aggregates by the scaffold protein p62, and the aggregates are then engulfed and degraded by autophagosomes. Here we report that p62 forms droplets in vivo which have liquid-like properties such as high sphericity, the ability to undergo fusion, and recovery after photobleaching. Recombinant p62 does not undergo phase separation in vitro; however, adding a K63 polyubiquitin chain to p62 induces p62 phase separation, which results in enrichment of high-molecular weight ubiquitin signals in p62 droplets. Mixing recombinant p62 with cytosol from p62(−/−) cells also results in p62 phase separation in a polyubiquitination-dependent manner. Mechanistically, p62 phase separation is dependent on p62 polymerization, the interaction between p62 and ubiquitin, and the valence of the polyubiquitin chain. Moreover, p62 phase separation can be regulated by post-translational modifications such as phosphorylation. Finally, we demonstrate that disease-associated mutations in p62 can affect phase separation. We propose that polyubiquitin chain-induced p62 phase separation drives autophagic cargo concentration and segregation. Nature Publishing Group UK 2018-03-05 2018-04 /pmc/articles/PMC5939046/ /pubmed/29507397 http://dx.doi.org/10.1038/s41422-018-0017-7 Text en © The Author(s) 2018 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.
spellingShingle Article
Sun, Daxiao
Wu, Rongbo
Zheng, Jingxiang
Li, Pilong
Yu, Li
Polyubiquitin chain-induced p62 phase separation drives autophagic cargo segregation
title Polyubiquitin chain-induced p62 phase separation drives autophagic cargo segregation
title_full Polyubiquitin chain-induced p62 phase separation drives autophagic cargo segregation
title_fullStr Polyubiquitin chain-induced p62 phase separation drives autophagic cargo segregation
title_full_unstemmed Polyubiquitin chain-induced p62 phase separation drives autophagic cargo segregation
title_short Polyubiquitin chain-induced p62 phase separation drives autophagic cargo segregation
title_sort polyubiquitin chain-induced p62 phase separation drives autophagic cargo segregation
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5939046/
https://www.ncbi.nlm.nih.gov/pubmed/29507397
http://dx.doi.org/10.1038/s41422-018-0017-7
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