1
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Garadi Suresh H, Bonneil E, Albert B, Dominique C, Costanzo M, Pons C, Masinas MPD, Shuteriqi E, Shore D, Henras AK, Thibault P, Boone C, Andrews BJ. K29-linked free polyubiquitin chains affect ribosome biogenesis and direct ribosomal proteins to the intranuclear quality control compartment. Mol Cell 2024; 84:2337-2352.e9. [PMID: 38870935 PMCID: PMC11193623 DOI: 10.1016/j.molcel.2024.05.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 01/25/2024] [Accepted: 05/17/2024] [Indexed: 06/15/2024]
Abstract
Ribosome assembly requires precise coordination between the production and assembly of ribosomal components. Mutations in ribosomal proteins that inhibit the assembly process or ribosome function are often associated with ribosomopathies, some of which are linked to defects in proteostasis. In this study, we examine the interplay between several yeast proteostasis enzymes, including deubiquitylases (DUBs) Ubp2 and Ubp14, and E3 ligases Ufd4 and Hul5, and we explore their roles in the regulation of the cellular levels of K29-linked unanchored polyubiquitin (polyUb) chains. Accumulating K29-linked unanchored polyUb chains associate with maturing ribosomes to disrupt their assembly, activate the ribosome assembly stress response (RASTR), and lead to the sequestration of ribosomal proteins at the intranuclear quality control compartment (INQ). These findings reveal the physiological relevance of INQ and provide insights into mechanisms of cellular toxicity associated with ribosomopathies.
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Affiliation(s)
- Harsha Garadi Suresh
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, 160 College Street, Toronto, ON M5S 3E1, Canada.
| | - Eric Bonneil
- Institute for Research in Immunology and Cancer (IRIC), Université de Montréal, Montréal, QC H3C 3J7, Canada
| | - Benjamin Albert
- Department of Molecular Biology, Institute of Genetics and Genomics of Geneva (iGE3), Geneva, Switzerland; Molecular, Cellular and Developmental Biology Unit (MCD), Centre for Integrative Biology (CBI), University of Toulouse, CNRS, UPS, Toulouse, France
| | - Carine Dominique
- Molecular, Cellular and Developmental Biology Unit (MCD), Centre for Integrative Biology (CBI), University of Toulouse, CNRS, UPS, Toulouse, France
| | - Michael Costanzo
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, 160 College Street, Toronto, ON M5S 3E1, Canada
| | - Carles Pons
- Institute for Research in Biomedicine (IRB Barcelona), Barcelona Institute for Science and Technology, Barcelona, Catalonia, Spain
| | - Myra Paz David Masinas
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, 160 College Street, Toronto, ON M5S 3E1, Canada
| | - Ermira Shuteriqi
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, 160 College Street, Toronto, ON M5S 3E1, Canada
| | - David Shore
- Department of Molecular Biology, Institute of Genetics and Genomics of Geneva (iGE3), Geneva, Switzerland
| | - Anthony K Henras
- Molecular, Cellular and Developmental Biology Unit (MCD), Centre for Integrative Biology (CBI), University of Toulouse, CNRS, UPS, Toulouse, France
| | - Pierre Thibault
- Institute for Research in Immunology and Cancer (IRIC), Université de Montréal, Montréal, QC H3C 3J7, Canada; Department of Chemistry, Université de Montréal, Montréal, QC H3C 3J7, Canada
| | - Charles Boone
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, 160 College Street, Toronto, ON M5S 3E1, Canada; Department of Molecular Genetics, University of Toronto, 160 College Street, Toronto, ON M5S 3E1, Canada.
| | - Brenda J Andrews
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, 160 College Street, Toronto, ON M5S 3E1, Canada; Department of Molecular Genetics, University of Toronto, 160 College Street, Toronto, ON M5S 3E1, Canada.
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2
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Kumar A, Mathew V, Stirling PC. Dynamics of DNA damage-induced nuclear inclusions are regulated by SUMOylation of Btn2. Nat Commun 2024; 15:3215. [PMID: 38615096 PMCID: PMC11016081 DOI: 10.1038/s41467-024-47615-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Accepted: 04/05/2024] [Indexed: 04/15/2024] Open
Abstract
Spatial compartmentalization is a key facet of protein quality control that serves to store disassembled or non-native proteins until triage to the refolding or degradation machinery can occur in a regulated manner. Yeast cells sequester nuclear proteins at intranuclear quality control bodies (INQ) in response to various stresses, although the regulation of this process remains poorly understood. Here we reveal the SUMO modification of the small heat shock protein Btn2 under DNA damage and place Btn2 SUMOylation in a pathway promoting protein clearance from INQ structures. Along with other chaperones, and degradation machinery, Btn2-SUMO promotes INQ clearance from cells recovering from genotoxic stress. These data link small heat shock protein post-translational modification to the regulation of protein sequestration in the yeast nucleus.
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Affiliation(s)
- Arun Kumar
- Terry Fox Laboratory, BC Cancer, 675 West 10th Avenue, Vancouver, BC, V5Z1L3, Canada
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, V6T1Z4, Canada
| | - Veena Mathew
- Terry Fox Laboratory, BC Cancer, 675 West 10th Avenue, Vancouver, BC, V5Z1L3, Canada
| | - Peter C Stirling
- Terry Fox Laboratory, BC Cancer, 675 West 10th Avenue, Vancouver, BC, V5Z1L3, Canada.
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, V6T1Z4, Canada.
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3
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Goncalves D, Duy DL, Peffer S, Morano KA. Cytoplasmic redox imbalance in the thioredoxin system activates Hsf1 and results in hyperaccumulation of the sequestrase Hsp42 with misfolded proteins. Mol Biol Cell 2024; 35:ar53. [PMID: 38381577 PMCID: PMC11064659 DOI: 10.1091/mbc.e23-07-0296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 02/09/2024] [Accepted: 02/16/2024] [Indexed: 02/23/2024] Open
Abstract
Cells employ multiple systems to maintain homeostasis when experiencing environmental stress. For example, the folding of nascent polypeptides is exquisitely sensitive to proteotoxic stressors including heat, pH, and oxidative stress, and is safeguarded by a network of protein chaperones that concentrate potentially toxic misfolded proteins into transient assemblies to promote folding or degradation. The redox environment itself is buffered by both cytosolic and organellar thioredoxin and glutathione pathways. How these systems are linked is poorly understood. Here, we determine that specific disruption of the cytosolic thioredoxin system resulted in constitutive activation of the heat shock response in Saccharomyces cerevisiae and accumulation of the sequestrase Hsp42 into an exaggerated and persistent juxtanuclear quality control (JUNQ) compartment. Terminally misfolded proteins also accumulated in this compartment in thioredoxin reductase (TRR1)-deficient cells, despite apparently normal formation and dissolution of transient cytoplasmic quality control (CytoQ) bodies during heat shock. Notably, cells lacking TRR1 and HSP42 exhibited severe synthetic slow growth exacerbated by oxidative stress, signifying a critical role for Hsp42 under redox-challenged conditions. Finally, we demonstrated that Hsp42 localization patterns in trr1∆ cells mimic those observed in chronically aging and glucose-starved cells, linking nutrient depletion and redox imbalance with management of misfolded proteins via a process of long-term sequestration.
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Affiliation(s)
- Davi Goncalves
- Department of Microbiology and Molecular Genetics, McGovern Medical School at UTHealth Houston, Houston, TX 77030
| | - Duong Long Duy
- Department of Microbiology and Molecular Genetics, McGovern Medical School at UTHealth Houston, Houston, TX 77030
| | - Sara Peffer
- Department of Microbiology and Molecular Genetics, McGovern Medical School at UTHealth Houston, Houston, TX 77030
- Microbiology and Infectious Disease Program, MD Anderson UTHealth Graduate School at UTHealth Houston, Houston, TX 77030
| | - Kevin A. Morano
- Department of Microbiology and Molecular Genetics, McGovern Medical School at UTHealth Houston, Houston, TX 77030
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4
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Kohler V, Kohler A, Berglund LL, Hao X, Gersing S, Imhof A, Nyström T, Höög JL, Ott M, Andréasson C, Büttner S. Nuclear Hsp104 safeguards the dormant translation machinery during quiescence. Nat Commun 2024; 15:315. [PMID: 38182580 PMCID: PMC10770042 DOI: 10.1038/s41467-023-44538-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Accepted: 12/15/2023] [Indexed: 01/07/2024] Open
Abstract
The resilience of cellular proteostasis declines with age, which drives protein aggregation and compromises viability. The nucleus has emerged as a key quality control compartment that handles misfolded proteins produced by the cytosolic protein biosynthesis system. Here, we find that age-associated metabolic cues target the yeast protein disaggregase Hsp104 to the nucleus to maintain a functional nuclear proteome during quiescence. The switch to respiratory metabolism and the accompanying decrease in translation rates direct cytosolic Hsp104 to the nucleus to interact with latent translation initiation factor eIF2 and to suppress protein aggregation. Hindering Hsp104 from entering the nucleus in quiescent cells results in delayed re-entry into the cell cycle due to compromised resumption of protein synthesis. In sum, we report that cytosolic-nuclear partitioning of the Hsp104 disaggregase is a critical mechanism to protect the latent protein synthesis machinery during quiescence in yeast, ensuring the rapid restart of translation once nutrients are replenished.
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Affiliation(s)
- Verena Kohler
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, 10691, Stockholm, Sweden
- Institute of Molecular Biosciences, University of Graz, 8010, Graz, Austria
- Department of Molecular Biology, Umeå University, 90187, Umeå, Sweden
| | - Andreas Kohler
- Institute of Molecular Biosciences, University of Graz, 8010, Graz, Austria
- Department of Biochemistry and Biophysics, Stockholm University, 10691, Stockholm, Sweden
- Department of Medical Biochemistry and Biophysics, Umeå University, 90187, Umeå, Sweden
| | - Lisa Larsson Berglund
- Department of Chemistry and Molecular Biology, University of Gothenburg, 40530, Gothenburg, Sweden
| | - Xinxin Hao
- Department of Microbiology and Immunology, University of Gothenburg, 40530, Gothenburg, Sweden
| | - Sarah Gersing
- The Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, 1165, Copenhagen, Denmark
| | - Axel Imhof
- Biomedical Center Munich, Faculty of Medicine, Ludwig Maximilian University of Munich, 82152, Planegg-Martinsried, Germany
| | - Thomas Nyström
- Department of Microbiology and Immunology, University of Gothenburg, 40530, Gothenburg, Sweden
| | - Johanna L Höög
- Department of Chemistry and Molecular Biology, University of Gothenburg, 40530, Gothenburg, Sweden
| | - Martin Ott
- Department of Biochemistry and Biophysics, Stockholm University, 10691, Stockholm, Sweden
- Department of Medical Biochemistry and Cell Biology, University of Gothenburg, 40530, Gothenburg, Sweden
| | - Claes Andréasson
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, 10691, Stockholm, Sweden.
| | - Sabrina Büttner
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, 10691, Stockholm, Sweden.
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5
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Gonçalves D, Peffer S, Morano KA. Cytoplasmic redox imbalance in the thioredoxin system activates Hsf1 and results in hyperaccumulation of the sequestrase Hsp42 with misfolded proteins. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.26.546610. [PMID: 37425817 PMCID: PMC10327208 DOI: 10.1101/2023.06.26.546610] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/11/2023]
Abstract
Cells employ multiple systems to maintain homeostasis when experiencing environmental stress. For example, the folding of nascent polypeptides is exquisitely sensitive to proteotoxic stressors including heat, pH and oxidative stress, and is safeguarded by a network of protein chaperones that concentrate potentially toxic misfolded proteins into transient assemblies to promote folding or degradation. The redox environment itself is buffered by both cytosolic and organellar thioredoxin and glutathione pathways. How these systems are linked is poorly understood. Here, we determine that specific disruption of the cytosolic thioredoxin system resulted in constitutive activation of the heat shock response in Saccharomyces cerevisiae and accumulation of the sequestrase Hsp42 into an exaggerated and persistent juxtanuclear quality control (JUNQ) compartment. Terminally misfolded proteins also accumulated in this compartment in thioredoxin reductase (TRR1)-deficient cells, despite apparently normal formation and dissolution of transient cytoplasmic quality control (CytoQ) bodies during heat shock. Notably, cells lacking TRR1 and HSP42 exhibited severe synthetic slow growth exacerbated by oxidative stress, signifying a critical role for Hsp42 under redox-challenged conditions. Finally, we demonstrated that Hsp42 localization patterns in trr1∆ cells mimic those observed in chronically aging and glucose-starved cells, linking nutrient depletion and redox imbalance with management of misfolded proteins via a mechanism of long-term sequestration.
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Affiliation(s)
- Davi Gonçalves
- Department of Microbiology and Molecular Genetics, McGovern Medical School at UTHealth Houston, Houston, TX USA
- Current address: Cemvita Factory, Houston, TX USA
| | - Sara Peffer
- Department of Microbiology and Molecular Genetics, McGovern Medical School at UTHealth Houston, Houston, TX USA
- MD Anderson UTHealth Graduate School at UTHealth Houston, Houston, TX USA
- Current address: Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX USA
| | - Kevin A. Morano
- Department of Microbiology and Molecular Genetics, McGovern Medical School at UTHealth Houston, Houston, TX USA
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6
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Suresh HG, Bonneil E, Albert B, Dominique C, Costanzo M, Pons C, David Masinas MP, Shuteriqi E, Shore D, Henras AK, Thibault P, Boone C, Andrews BJ. K29-linked unanchored polyubiquitin chains disrupt ribosome biogenesis and direct ribosomal proteins to the Intranuclear Quality control compartment (INQ). BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.03.539259. [PMID: 37205480 PMCID: PMC10187189 DOI: 10.1101/2023.05.03.539259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Ribosome assembly requires precise coordination between the production and assembly of ribosomal components. Mutations in ribosomal proteins that inhibit the assembly process or ribosome function are often associated with Ribosomopathies, some of which are linked to defects in proteostasis. In this study, we examine the interplay between several yeast proteostasis enzymes, including deubiquitylases (DUBs), Ubp2 and Ubp14, and E3 ligases, Ufd4 and Hul5, and we explore their roles in the regulation of the cellular levels of K29-linked unanchored polyubiquitin (polyUb) chains. Accumulating K29-linked unanchored polyUb chains associate with maturing ribosomes to disrupt their assembly, activate the Ribosome assembly stress response (RASTR), and lead to the sequestration of ribosomal proteins at the Intranuclear Quality control compartment (INQ). These findings reveal the physiological relevance of INQ and provide insights into mechanisms of cellular toxicity associated with Ribosomopathies.
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7
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Kumar A, Mathew V, Stirling PC. Nuclear protein quality control in yeast: the latest INQuiries. J Biol Chem 2022; 298:102199. [PMID: 35760103 PMCID: PMC9305344 DOI: 10.1016/j.jbc.2022.102199] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 06/07/2022] [Accepted: 06/19/2022] [Indexed: 11/29/2022] Open
Abstract
The nucleus is a highly organized organelle with an intricate substructure of chromatin, RNAs, and proteins. This environment represents a challenge for maintaining protein quality control, since non-native proteins may interact inappropriately with other macromolecules and thus interfere with their function. Maintaining a healthy nuclear proteome becomes imperative during times of stress, such as upon DNA damage, heat shock, or starvation, when the proteome must be remodeled to effect cell survival. This is accomplished with the help of nuclear-specific chaperones, degradation pathways, and specialized structures known as protein quality control (PQC) sites that sequester proteins to help rapidly remodel the nuclear proteome. In this review, we focus on the current knowledge of PQC sites in Saccharomyces cerevisiae, particularly on a specialized nuclear PQC site called the intranuclear quality control site, a poorly understood nuclear inclusion that coordinates dynamic proteome triage decisions in yeast.
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Affiliation(s)
- Arun Kumar
- Terry Fox Laboratory, BC Cancer Agency, Vancouver, Canada; Dept. of Medical Genetics, University of British Columbia, Vancouver Canada
| | - Veena Mathew
- Terry Fox Laboratory, BC Cancer Agency, Vancouver, Canada
| | - Peter C Stirling
- Terry Fox Laboratory, BC Cancer Agency, Vancouver, Canada; Dept. of Medical Genetics, University of British Columbia, Vancouver Canada.
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8
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Mathew V, Kumar A, Jiang YK, West K, Tam AS, Stirling PC. Cdc48 regulates intranuclear quality control sequestration of the Hsh155 splicing factor in budding yeast. J Cell Sci 2020; 133:jcs.252551. [PMID: 33172985 DOI: 10.1242/jcs.252551] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 10/30/2020] [Indexed: 11/20/2022] Open
Abstract
Cdc48 (known as VCP in mammals) is a highly conserved ATPase chaperone that plays an essential role in the assembly and disassembly of protein-DNA complexes and in degradation of misfolded proteins. We find that in Saccharomyces cerevisiae budding yeast, Cdc48 accumulates during cellular stress at intranuclear protein quality control sites (INQ). We show that Cdc48 function is required to suppress INQ formation under non-stress conditions and to promote recovery following genotoxic stress. Cdc48 physically associates with the INQ substrate and splicing factor Hsh155, and regulates its assembly with partner proteins. Accordingly, cdc48 mutants have defects in splicing and show spontaneous distribution of Hsh155 to INQ aggregates, where it is stabilized. Overall, this study shows that Cdc48 regulates deposition of proteins at INQ and suggests a previously unknown role for Cdc48 in the regulation or stabilization of splicing subcomplexes.This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Veena Mathew
- Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver V5Z 1L3, Canada
| | - Arun Kumar
- Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver V5Z 1L3, Canada.,Department of Medical Genetics, University of British Columbia, Vancouver V6H 3N1, Canada
| | - Yangyang K Jiang
- Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver V5Z 1L3, Canada
| | - Kyra West
- Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver V5Z 1L3, Canada
| | - Annie S Tam
- Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver V5Z 1L3, Canada.,Department of Medical Genetics, University of British Columbia, Vancouver V6H 3N1, Canada
| | - Peter C Stirling
- Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver V5Z 1L3, Canada .,Department of Medical Genetics, University of British Columbia, Vancouver V6H 3N1, Canada
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9
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Sun C. The SF3b complex: splicing and beyond. Cell Mol Life Sci 2020; 77:3583-3595. [PMID: 32140746 PMCID: PMC7452928 DOI: 10.1007/s00018-020-03493-z] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Revised: 02/13/2020] [Accepted: 02/20/2020] [Indexed: 12/17/2022]
Abstract
The SF3b complex is an intrinsic component of the functional U2 small nuclear ribonucleoprotein (snRNP). As U2 snRNP enters nuclear pre-mRNA splicing, SF3b plays key roles in recognizing the branch point sequence (BPS) and facilitating spliceosome assembly and activation. Since the discovery of SF3b, substantial progress has been made in elucidating its molecular mechanism during splicing. In addition, numerous recent studies indicate that SF3b and its components are engaged in various molecular and cellular events that are beyond the canonical role in splicing. This review summarizes the current knowledge on the SF3b complex and highlights its multiple roles in splicing and beyond.
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Affiliation(s)
- Chengfu Sun
- Non-coding RNA and Drug Discovery Key Laboratory of Sichuan Province, Chengdu Medical College, Chengdu, 610500, China.
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10
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Jiang Y, Berg MD, Genereaux J, Ahmed K, Duennwald ML, Brandl CJ, Lajoie P. Sfp1 links TORC1 and cell growth regulation to the yeast SAGA‐complex component Tra1 in response to polyQ proteotoxicity. Traffic 2019; 20:267-283. [DOI: 10.1111/tra.12637] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 02/08/2019] [Accepted: 02/08/2019] [Indexed: 12/18/2022]
Affiliation(s)
- Yuwei Jiang
- Department of Anatomy and Cell BiologyThe University of Western Ontario London Ontario Canada
| | - Matthew D. Berg
- Department of BiochemistryThe University of Western Ontario London Ontario Canada
| | - Julie Genereaux
- Department of Anatomy and Cell BiologyThe University of Western Ontario London Ontario Canada
- Department of BiochemistryThe University of Western Ontario London Ontario Canada
| | - Khadija Ahmed
- Department of Anatomy and Cell BiologyThe University of Western Ontario London Ontario Canada
| | - Martin L. Duennwald
- Department of Anatomy and Cell BiologyThe University of Western Ontario London Ontario Canada
- Department of Pathology and Laboratory MedicineThe University of Western Ontario London Ontario Canada
| | | | - Patrick Lajoie
- Department of Anatomy and Cell BiologyThe University of Western Ontario London Ontario Canada
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Abstract
From bacteria to humans, ancient stress responses enable organisms to contend with damage to both the genome and the proteome. These pathways have long been viewed as fundamentally separate responses. Yet recent discoveries from multiple fields have revealed surprising links between the two. Many DNA-damaging agents also target proteins, and mutagenesis induced by DNA damage produces variant proteins that are prone to misfolding, degradation, and aggregation. Likewise, recent studies have observed pervasive engagement of a p53-mediated response, and other factors linked to maintenance of genomic integrity, in response to misfolded protein stress. Perhaps most remarkably, protein aggregation and self-assembly has now been observed in multiple proteins that regulate the DNA damage response. The importance of these connections is highlighted by disease models of both cancer and neurodegeneration, in which compromised DNA repair machinery leads to profound defects in protein quality control, and vice versa.
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