Stalled disomes marked by Hel2-dependent ubiquitin chains undergo Ubp2/Ubp3-mediated deubiquitination upon translational run-off
Abstract Stalled ribosomes cause collisions, impair protein synthesis, and generate potentially harmful truncated polypeptides. Eukaryotic cells utilize the ribosome-associated quality control (RQC) and no-go mRNA decay (NGD) pathways to resolve these problems. In yeast, the E3 ubiquitin ligase Hel2...
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Nature Portfolio
2025-01-01
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| Series: | Communications Biology |
| Online Access: | https://doi.org/10.1038/s42003-025-07569-z |
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| author | Mario Scazzari Ying Zhang Anna Moddemann Sabine Rospert |
| author_facet | Mario Scazzari Ying Zhang Anna Moddemann Sabine Rospert |
| author_sort | Mario Scazzari |
| collection | DOAJ |
| description | Abstract Stalled ribosomes cause collisions, impair protein synthesis, and generate potentially harmful truncated polypeptides. Eukaryotic cells utilize the ribosome-associated quality control (RQC) and no-go mRNA decay (NGD) pathways to resolve these problems. In yeast, the E3 ubiquitin ligase Hel2 recognizes and polyubiquitinates disomes and trisomes at the 40S ribosomal protein Rps20/uS10, thereby priming ribosomes for further steps in the RQC/NGD pathways. Recent studies have revealed high concentrations of disomes and trisomes in unstressed cells, raising the question of whether and how Hel2 selects long-term stalled disomes and trisomes. This study presents quantitative analysis of in vivo-formed Hel2•ribosome complexes and the dynamics of Hel2-dependent Rps20 ubiquitination and Ubp2/Ubp3-dependent deubiquitination. Our findings show that Hel2 occupancy progressively increases from translating monosomes to disomes and trisomes. We demonstrate that disomes and trisomes with mono- or di-ubiquitinated Rps20 resolve independently of the RQC component Slh1, while those with tri- and tetra-ubiquitinated Rps20 do not. Based on the results, we propose a model in which Hel2 translates the duration of ribosome stalling into polyubiquitin chain length. This mechanism allows for the distinction between transient and long-term stalling, providing the RQC machinery with a means to select fatally stalled ribosomes over transiently stalled ones. |
| format | Article |
| id | doaj-art-176433d9b62c43ae985981862aa97dd4 |
| institution | Kabale University |
| issn | 2399-3642 |
| language | English |
| publishDate | 2025-01-01 |
| publisher | Nature Portfolio |
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| series | Communications Biology |
| spelling | doaj-art-176433d9b62c43ae985981862aa97dd42025-02-02T12:37:14ZengNature PortfolioCommunications Biology2399-36422025-01-018111610.1038/s42003-025-07569-zStalled disomes marked by Hel2-dependent ubiquitin chains undergo Ubp2/Ubp3-mediated deubiquitination upon translational run-offMario Scazzari0Ying Zhang1Anna Moddemann2Sabine Rospert3Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of FreiburgInstitute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of FreiburgInstitute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of FreiburgInstitute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of FreiburgAbstract Stalled ribosomes cause collisions, impair protein synthesis, and generate potentially harmful truncated polypeptides. Eukaryotic cells utilize the ribosome-associated quality control (RQC) and no-go mRNA decay (NGD) pathways to resolve these problems. In yeast, the E3 ubiquitin ligase Hel2 recognizes and polyubiquitinates disomes and trisomes at the 40S ribosomal protein Rps20/uS10, thereby priming ribosomes for further steps in the RQC/NGD pathways. Recent studies have revealed high concentrations of disomes and trisomes in unstressed cells, raising the question of whether and how Hel2 selects long-term stalled disomes and trisomes. This study presents quantitative analysis of in vivo-formed Hel2•ribosome complexes and the dynamics of Hel2-dependent Rps20 ubiquitination and Ubp2/Ubp3-dependent deubiquitination. Our findings show that Hel2 occupancy progressively increases from translating monosomes to disomes and trisomes. We demonstrate that disomes and trisomes with mono- or di-ubiquitinated Rps20 resolve independently of the RQC component Slh1, while those with tri- and tetra-ubiquitinated Rps20 do not. Based on the results, we propose a model in which Hel2 translates the duration of ribosome stalling into polyubiquitin chain length. This mechanism allows for the distinction between transient and long-term stalling, providing the RQC machinery with a means to select fatally stalled ribosomes over transiently stalled ones.https://doi.org/10.1038/s42003-025-07569-z |
| spellingShingle | Mario Scazzari Ying Zhang Anna Moddemann Sabine Rospert Stalled disomes marked by Hel2-dependent ubiquitin chains undergo Ubp2/Ubp3-mediated deubiquitination upon translational run-off Communications Biology |
| title | Stalled disomes marked by Hel2-dependent ubiquitin chains undergo Ubp2/Ubp3-mediated deubiquitination upon translational run-off |
| title_full | Stalled disomes marked by Hel2-dependent ubiquitin chains undergo Ubp2/Ubp3-mediated deubiquitination upon translational run-off |
| title_fullStr | Stalled disomes marked by Hel2-dependent ubiquitin chains undergo Ubp2/Ubp3-mediated deubiquitination upon translational run-off |
| title_full_unstemmed | Stalled disomes marked by Hel2-dependent ubiquitin chains undergo Ubp2/Ubp3-mediated deubiquitination upon translational run-off |
| title_short | Stalled disomes marked by Hel2-dependent ubiquitin chains undergo Ubp2/Ubp3-mediated deubiquitination upon translational run-off |
| title_sort | stalled disomes marked by hel2 dependent ubiquitin chains undergo ubp2 ubp3 mediated deubiquitination upon translational run off |
| url | https://doi.org/10.1038/s42003-025-07569-z |
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