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Chauhan G, Bremer A, Dar F, Mittag T, Pappu RV. Crowder titrations enable the quantification of driving forces for macromolecular phase separation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.03.547544. [PMID: 37461587 PMCID: PMC10350001 DOI: 10.1101/2023.07.03.547544] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/22/2023]
Abstract
Macromolecular solubility is an important contributor to the driving forces for phase separation. Formally, the driving forces in a binary mixture comprising a macromolecule dissolved in a solvent can be quantified in terms of the saturation concentration, which is the threshold macromolecular concentration above which the mixture separates into coexisting dense and dilute phases. Additionally, the second virial coefficient, which measures the effective strength of solvent-mediated intermolecular interactions provides direct assessments of solvent quality. The sign and magnitude of second virial coefficients will be governed by a combination of solution conditions and the nature of the macromolecule of interest. Here, we show, using a combination of theory, simulation, and in vitro experiments, that titrations of crowders, providing they are true depletants, can be used to extract the intrinsic driving forces for macromolecular phase separation. This refers to saturation concentrations in the absence of crowders and the second virial coefficients that quantify the magnitude of the incompatibility between macromolecules and the solvent. Our results show how the depletion-mediated attractions afforded by crowders can be leveraged to obtain comparative assessments of macromolecule-specific, intrinsic driving forces for phase separation. SIGNIFICANCE Phase separation has emerged as a process of significant relevance to sorting macromolecules into distinct compartments, thereby enabling spatial and temporal control over cellular matter. Considerable effort is being invested into uncovering the driving forces that enable the separation of macromolecular solutions into coexisting phases. At its heart, this process is governed by the balance of macromolecule-solvent, inter-macromolecule, and solvent-solvent interactions. We show that the driving forces for phase separation, including the coefficients that measure interaction strengths between macromolecules, can be extracted by titrating the concentrations of crowders that enable macromolecules to phase separate at lower concentrations. Our work paves the way to leverage specific categories of measurements for quantitative characterizations of driving forces for phase separation.
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Fodder K, Murthy M, Rizzu P, Toomey CE, Hasan R, Humphrey J, Raj T, Lunnon K, Mill J, Heutink P, Lashley T, Bettencourt C. Brain DNA methylomic analysis of frontotemporal lobar degeneration reveals OTUD4 in shared dysregulated signatures across pathological subtypes. Acta Neuropathol 2023; 146:77-95. [PMID: 37149835 PMCID: PMC10261190 DOI: 10.1007/s00401-023-02583-z] [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: 12/06/2022] [Revised: 04/28/2023] [Accepted: 04/28/2023] [Indexed: 05/08/2023]
Abstract
Frontotemporal lobar degeneration (FTLD) is an umbrella term describing the neuropathology of a clinically, genetically and pathologically heterogeneous group of diseases, including frontotemporal dementia (FTD) and progressive supranuclear palsy (PSP). Among the major FTLD pathological subgroups, FTLD with TDP-43 positive inclusions (FTLD-TDP) and FTLD with tau-positive inclusions (FTLD-tau) are the most common, representing about 90% of the cases. Although alterations in DNA methylation have been consistently associated with neurodegenerative diseases, including Alzheimer's disease and Parkinson's disease, little is known for FTLD and its heterogeneous subgroups and subtypes. The main goal of this study was to investigate DNA methylation variation in FTLD-TDP and FTLD-tau. We used frontal cortex genome-wide DNA methylation profiles from three FTLD cohorts (142 FTLD cases and 92 controls), generated using the Illumina 450K or EPIC microarrays. We performed epigenome-wide association studies (EWAS) for each cohort followed by meta-analysis to identify shared differentially methylated loci across FTLD subgroups/subtypes. In addition, we used weighted gene correlation network analysis to identify co-methylation signatures associated with FTLD and other disease-related traits. Wherever possible, we also incorporated relevant gene/protein expression data. After accounting for a conservative Bonferroni multiple testing correction, the EWAS meta-analysis revealed two differentially methylated loci in FTLD, one annotated to OTUD4 (5'UTR-shore) and the other to NFATC1 (gene body-island). Of these loci, OTUD4 showed consistent upregulation of mRNA and protein expression in FTLD. In addition, in the three independent co-methylation networks, OTUD4-containing modules were enriched for EWAS meta-analysis top loci and were strongly associated with the FTLD status. These co-methylation modules were enriched for genes implicated in the ubiquitin system, RNA/stress granule formation and glutamatergic synaptic signalling. Altogether, our findings identified novel FTLD-associated loci, and support a role for DNA methylation as a mechanism involved in the dysregulation of biological processes relevant to FTLD, highlighting novel potential avenues for therapeutic development.
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Affiliation(s)
- Katherine Fodder
- Queen Square Brain Bank for Neurological Disorders, UCL Queen Square Institute of Neurology, London, UK
- Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, London, UK
| | - Megha Murthy
- Queen Square Brain Bank for Neurological Disorders, UCL Queen Square Institute of Neurology, London, UK
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, London, UK
| | - Patrizia Rizzu
- German Center for Neurodegenerative Diseases (DZNE), Tübingen, Germany
| | - Christina E Toomey
- Queen Square Brain Bank for Neurological Disorders, UCL Queen Square Institute of Neurology, London, UK
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, London, UK
- The Francis Crick Institute, London, UK
| | - Rahat Hasan
- Nash Family Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Jack Humphrey
- Nash Family Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Towfique Raj
- Nash Family Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Katie Lunnon
- Department of Clinical and Biomedical Sciences, Faculty of Health and Life Sciences, University of Exeter, Exeter, UK
| | - Jonathan Mill
- Department of Clinical and Biomedical Sciences, Faculty of Health and Life Sciences, University of Exeter, Exeter, UK
| | - Peter Heutink
- German Center for Neurodegenerative Diseases (DZNE), Tübingen, Germany
- Alector, Inc., South San Francisco, CA, USA
| | - Tammaryn Lashley
- Queen Square Brain Bank for Neurological Disorders, UCL Queen Square Institute of Neurology, London, UK
- Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, London, UK
| | - Conceição Bettencourt
- Queen Square Brain Bank for Neurological Disorders, UCL Queen Square Institute of Neurology, London, UK.
- Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, London, UK.
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Ma Y, Farny NG. Connecting the dots: Neuronal senescence, stress granules, and neurodegeneration. Gene 2023; 871:147437. [PMID: 37084987 PMCID: PMC10205695 DOI: 10.1016/j.gene.2023.147437] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Revised: 04/09/2023] [Accepted: 04/14/2023] [Indexed: 04/23/2023]
Abstract
Cellular senescence increases with aging. While senescence is associated with an exit of the cell cycle, there is ample evidence that post-mitotic cells including neurons can undergo senescence as the brain ages, and that senescence likely contributes significantly to the progression of neurodegenerative diseases (ND) such as Alzheimer's Disease (AD) and Amyotrophic Lateral Sclerosis (ALS). Stress granules (SGs) are stress-induced cytoplasmic biomolecular condensates of RNA and proteins, which have been linked to the development of AD and ALS. The SG seeding hypothesis of NDs proposes that chronic stress in aging neurons results in static SGs that progress into pathological aggregates Alterations in SG dynamics have also been linked to senescence, though studies that link SGs and senescence in the context of NDs and the aging brain have not yet been performed. In this Review, we summarize the literature on senescence, and explore the contribution of senescence to the aging brain. We describe senescence phenotypes in aging neurons and glia, and their links to neuroinflammation and the development of AD and ALS. We further examine the relationships of SGs to senescence and to ND. We propose a new hypothesis that neuronal senescence may contribute to the mechanism of SG seeding in ND by altering SG dynamics in aged cells, thereby providing additional aggregation opportunities within aged neurons.
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Affiliation(s)
- Yizhe Ma
- Department of Biology and Biotechnology, Worcester Polytechnic Institute, Worcester, MA, USA
| | - Natalie G Farny
- Department of Biology and Biotechnology, Worcester Polytechnic Institute, Worcester, MA, USA.
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Ma B, Ju A, Zhang S, An Q, Xu S, Liu J, Yu L, Fu Y, Luo Y. Albumosomes formed by cytoplasmic pre-folding albumin maintain mitochondrial homeostasis and inhibit nonalcoholic fatty liver disease. Signal Transduct Target Ther 2023; 8:229. [PMID: 37321990 PMCID: PMC10272166 DOI: 10.1038/s41392-023-01437-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2022] [Revised: 03/01/2023] [Accepted: 04/06/2023] [Indexed: 06/17/2023] Open
Abstract
Hepatic mitochondrial dysfunction contributes to the progression of nonalcoholic fatty liver disease (NAFLD). However, the factors that maintain mitochondrial homeostasis, especially in hepatocytes, are largely unknown. Hepatocytes synthesize various high-level plasma proteins, among which albumin is most abundant. In this study, we found that pre-folding albumin in the cytoplasm is completely different from folded albumin in the serum. Mechanistically, endogenous pre-folding albumin undergoes phase transition in the cytoplasm to form a shell-like spherical structure, which we call the "albumosome". Albumosomes interact with and trap pre-folding carnitine palmitoyltransferase 2 (CPT2) in the cytoplasm. Albumosomes control the excessive sorting of CPT2 to the mitochondria under high-fat-diet-induced stress conditions; in this way, albumosomes maintain mitochondrial homeostasis from exhaustion. Physiologically, albumosomes accumulate in hepatocytes during murine aging and protect the livers of aged mice from mitochondrial damage and fat deposition. Morphologically, mature albumosomes have a mean diameter of 4μm and are surrounded by heat shock protein Hsp90 and Hsp70 family proteins, forming a larger shell. The Hsp90 inhibitor 17-AAG promotes hepatic albumosomal accumulation in vitro and in vivo, through which suppressing the progression of NAFLD in mice.
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Affiliation(s)
- Boyuan Ma
- School of Life Sciences, Tsinghua University, 100084, Beijing, China
- The National Engineering Research Center for Protein Technology, Tsinghua University, 100084, Beijing, China
- Beijing Key Laboratory for Protein Therapeutics, Tsinghua University, 100084, Beijing, China
| | - Anji Ju
- School of Life Sciences, Tsinghua University, 100084, Beijing, China
- The National Engineering Research Center for Protein Technology, Tsinghua University, 100084, Beijing, China
- Beijing Key Laboratory for Protein Therapeutics, Tsinghua University, 100084, Beijing, China
| | - Shaosen Zhang
- School of Life Sciences, Tsinghua University, 100084, Beijing, China
- The National Engineering Research Center for Protein Technology, Tsinghua University, 100084, Beijing, China
- Beijing Key Laboratory for Protein Therapeutics, Tsinghua University, 100084, Beijing, China
- Department of Etiology and Carcinogenesis, National Cancer Center/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, 100021, Beijing, China
| | - Qi An
- School of Life Sciences, Tsinghua University, 100084, Beijing, China
- The National Engineering Research Center for Protein Technology, Tsinghua University, 100084, Beijing, China
- Beijing Key Laboratory for Protein Therapeutics, Tsinghua University, 100084, Beijing, China
| | - Siran Xu
- School of Life Sciences, Tsinghua University, 100084, Beijing, China
- The National Engineering Research Center for Protein Technology, Tsinghua University, 100084, Beijing, China
- Beijing Key Laboratory for Protein Therapeutics, Tsinghua University, 100084, Beijing, China
| | - Jie Liu
- School of Life Sciences, Tsinghua University, 100084, Beijing, China
- The National Engineering Research Center for Protein Technology, Tsinghua University, 100084, Beijing, China
- Beijing Key Laboratory for Protein Therapeutics, Tsinghua University, 100084, Beijing, China
- Immunogenetics Laboratory, Shenzhen Blood Center, 518025, Shenzhen, Guangdong, China
| | - Li Yu
- State Key Laboratory of Membrane Biology, Tsinghua University-Peking University Joint Centre for Life Sciences, Beijing Frontier Research Center for Biological Structure, School of Life Sciences, Tsinghua University, 100084, Beijing, China
| | - Yan Fu
- School of Life Sciences, Tsinghua University, 100084, Beijing, China.
- The National Engineering Research Center for Protein Technology, Tsinghua University, 100084, Beijing, China.
- Beijing Key Laboratory for Protein Therapeutics, Tsinghua University, 100084, Beijing, China.
| | - Yongzhang Luo
- School of Life Sciences, Tsinghua University, 100084, Beijing, China.
- The National Engineering Research Center for Protein Technology, Tsinghua University, 100084, Beijing, China.
- Beijing Key Laboratory for Protein Therapeutics, Tsinghua University, 100084, Beijing, China.
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55
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Zheng H, Peng K, Gou X, Ju C, Zhang H. RNA recruitment switches the fate of protein condensates from autophagic degradation to accumulation. J Cell Biol 2023; 222:e202210104. [PMID: 37014300 PMCID: PMC10075224 DOI: 10.1083/jcb.202210104] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Revised: 02/07/2023] [Accepted: 03/01/2023] [Indexed: 04/05/2023] Open
Abstract
Protein condensates can evade autophagic degradation under stress or pathological conditions. However, the underlying mechanisms are unclear. Here, we demonstrate that RNAs switch the fate of condensates in Caenorhabditis elegans. PGL granules undergo autophagic degradation in embryos laid under normal conditions and accumulate in embryos laid under heat stress conditions to confer stress adaptation. In heat-stressed embryos, mRNAs and RNA control factors partition into PGL granules. Depleting proteins involved in mRNA biogenesis and stability suppresses PGL granule accumulation and triggers their autophagic degradation, while loss of activity of proteins involved in RNA turnover facilitates accumulation. RNAs facilitate LLPS of PGL granules, enhance their liquidity, and also inhibit recruitment of the gelation-promoting scaffold protein EPG-2 to PGL granules. Thus, RNAs are important for controlling the susceptibility of phase-separated protein condensates to autophagic degradation. Our work provides insights into the accumulation of ribonucleoprotein aggregates associated with the pathogenesis of various diseases.
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Affiliation(s)
- Hui Zheng
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Kangfu Peng
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Xiaomeng Gou
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Chen Ju
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Hong Zhang
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
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56
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Park SH, Lee SE, Jeon JH, Lee JH, Itakura E, Chang S, Choi WH, Lee MJ. Formation of aggresomes with hydrogel-like characteristics by proteasome inhibition. BIOCHIMICA ET BIOPHYSICA ACTA. GENE REGULATORY MECHANISMS 2023; 1866:194932. [PMID: 36997115 DOI: 10.1016/j.bbagrm.2023.194932] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 02/08/2023] [Accepted: 03/21/2023] [Indexed: 03/30/2023]
Abstract
The spatiotemporal sequestration of misfolded proteins is a mechanism by which cells counterbalance proteome homeostasis upon exposure to various stress stimuli. Chronic inhibition of proteasomes results in a large, juxtanuclear, membrane-less inclusion, known as the aggresome. Although the molecular mechanisms driving its formation, clearance, and pathophysiological implications are continuously being uncovered, the biophysical aspects of aggresomes remain largely uncharacterized. Using fluorescence recovery after photobleaching and liquid droplet disruption assays, we found that the aggresomes are a homogeneously blended condensates with liquid-like properties similar to droplets formed via liquid-liquid phase separation. However, unlike fluidic liquid droplets, aggresomes have more viscosity and hydrogel-like characteristics. We also observed that the inhibition of aggresome formation using microtubule-disrupting agents resulted in less soluble and smaller cytoplasmic speckles, which was associated with marked cytotoxicity. Therefore, the aggresome appears to be cytoprotective and serves as a temporal reservoir for dysfunctional proteasomes and substrates that need to be degraded. Our results suggest that the aggresome assembles through distinct and potentially sequential processes of energy-dependent retrograde transportation and spontaneous condensation into a hydrogel.
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Affiliation(s)
- Seo Hyeong Park
- Department of Biochemistry and Molecular Biology, Seoul National University College of Medicine, Seoul 03080, Republic of Korea; Department of Biomedical Sciences, Seoul National University Graduate School, Seoul 03080, Republic of Korea
| | - Sang-Eun Lee
- Department of Physiology and Biomedical Sciences, Seoul National University College of Medicine, Seoul 03080, Republic of Korea
| | - Jun Hyoung Jeon
- Department of Biochemistry and Molecular Biology, Seoul National University College of Medicine, Seoul 03080, Republic of Korea; Seegene, Inc., Seoul 05548, Republic of Korea
| | - Jung Hoon Lee
- Department of Biochemistry and Molecular Biology, Seoul National University College of Medicine, Seoul 03080, Republic of Korea; Cellular Degradation Biology Center, Seoul National University College of Medicine, Seoul 03080, Republic of Korea
| | - Eisuke Itakura
- Department of Biology, Graduate School of Science, Chiba University, Inage-ku, Chiba 263-8522, Japan
| | - Sunghoe Chang
- Department of Biomedical Sciences, Seoul National University Graduate School, Seoul 03080, Republic of Korea; Department of Physiology and Biomedical Sciences, Seoul National University College of Medicine, Seoul 03080, Republic of Korea.
| | - Won Hoon Choi
- Department of Biochemistry and Molecular Biology, Seoul National University College of Medicine, Seoul 03080, Republic of Korea; Cellular Degradation Biology Center, Seoul National University College of Medicine, Seoul 03080, Republic of Korea.
| | - Min Jae Lee
- Department of Biochemistry and Molecular Biology, Seoul National University College of Medicine, Seoul 03080, Republic of Korea; Department of Biomedical Sciences, Seoul National University Graduate School, Seoul 03080, Republic of Korea; Ischemic/Hypoxic Disease Institute, Convergence Research Center for Dementia, Seoul National University College of Medicine, Seoul 03080, Republic of Korea; Cellular Degradation Biology Center, Seoul National University College of Medicine, Seoul 03080, Republic of Korea.
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57
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Son A, Huizar Cabral V, Huang Z, Litberg TJ, Horowitz S. G-quadruplexes rescuing protein folding. Proc Natl Acad Sci U S A 2023; 120:e2216308120. [PMID: 37155907 PMCID: PMC10194009 DOI: 10.1073/pnas.2216308120] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Accepted: 04/12/2023] [Indexed: 05/10/2023] Open
Abstract
Maintaining the health of the proteome is a critical cellular task. Recently, we found G-quadruplex (G4) nucleic acids are especially potent at preventing protein aggregation in vitro and could at least indirectly improve the protein folding environment of Escherichia coli. However, the roles of G4s in protein folding were not yet explored. Here, through in vitro protein folding experiments, we discover that G4s can accelerate protein folding by rescuing kinetically trapped intermediates to both native and near-native folded states. Time-course folding experiments in E. coli further demonstrate that these G4s primarily improve protein folding quality in E. coli as opposed to preventing protein aggregation. The ability of a short nucleic acid to rescue protein folding opens up the possibility of nucleic acids and ATP-independent chaperones to play considerable roles in dictating the ultimate folding fate of proteins.
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Affiliation(s)
- Ahyun Son
- Department of Chemistry & Biochemistry, Knoebel Institute for Healthy Aging, University of Denver, Denver, CO80208
| | - Veronica Huizar Cabral
- Department of Chemistry & Biochemistry, Knoebel Institute for Healthy Aging, University of Denver, Denver, CO80208
| | - Zijue Huang
- Department of Chemistry & Biochemistry, Knoebel Institute for Healthy Aging, University of Denver, Denver, CO80208
| | - Theodore J. Litberg
- Department of Chemistry & Biochemistry, Knoebel Institute for Healthy Aging, University of Denver, Denver, CO80208
| | - Scott Horowitz
- Department of Chemistry & Biochemistry, Knoebel Institute for Healthy Aging, University of Denver, Denver, CO80208
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Kinger S, Dubey AR, Kumar P, Jagtap YA, Choudhary A, Kumar A, Prajapati VK, Dhiman R, Mishra A. Molecular Chaperones' Potential against Defective Proteostasis of Amyotrophic Lateral Sclerosis. Cells 2023; 12:cells12091302. [PMID: 37174703 PMCID: PMC10177248 DOI: 10.3390/cells12091302] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Revised: 04/24/2023] [Accepted: 04/27/2023] [Indexed: 05/15/2023] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a neuronal degenerative condition identified via a build-up of mutant aberrantly folded proteins. The native folding of polypeptides is mediated by molecular chaperones, preventing their pathogenic aggregation. The mutant protein expression in ALS is linked with the entrapment and depletion of chaperone capacity. The lack of a thorough understanding of chaperones' involvement in ALS pathogenesis presents a significant challenge in its treatment. Here, we review how the accumulation of the ALS-linked mutant FUS, TDP-43, SOD1, and C9orf72 proteins damage cellular homeostasis mechanisms leading to neuronal loss. Further, we discuss how the HSP70 and DNAJ family co-chaperones can act as potential targets for reducing misfolded protein accumulation in ALS. Moreover, small HSPB1 and HSPB8 chaperones can facilitate neuroprotection and prevent stress-associated misfolded protein apoptosis. Designing therapeutic strategies by pharmacologically enhancing cellular chaperone capacity to reduce mutant protein proteotoxic effects on ALS pathomechanisms can be a considerable advancement. Chaperones, apart from directly interacting with misfolded proteins for protein quality control, can also filter their toxicity by initiating strong stress-response pathways, modulating transcriptional expression profiles, and promoting anti-apoptotic functions. Overall, these properties of chaperones make them an attractive target for gaining fundamental insights into misfolded protein disorders and designing more effective therapies against ALS.
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Affiliation(s)
- Sumit Kinger
- Cellular and Molecular Neurobiology Unit, Indian Institute of Technology Jodhpur, Jodhpur 342037, India
| | - Ankur Rakesh Dubey
- Cellular and Molecular Neurobiology Unit, Indian Institute of Technology Jodhpur, Jodhpur 342037, India
| | - Prashant Kumar
- Cellular and Molecular Neurobiology Unit, Indian Institute of Technology Jodhpur, Jodhpur 342037, India
| | - Yuvraj Anandrao Jagtap
- Cellular and Molecular Neurobiology Unit, Indian Institute of Technology Jodhpur, Jodhpur 342037, India
| | - Akash Choudhary
- Cellular and Molecular Neurobiology Unit, Indian Institute of Technology Jodhpur, Jodhpur 342037, India
| | - Amit Kumar
- Discipline of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Simrol, Indore 453552, India
| | - Vijay Kumar Prajapati
- Department of Biochemistry, School of Life Sciences, Central University of Rajasthan, Ajmer 305817, India
| | - Rohan Dhiman
- Laboratory of Mycobacterial Immunology, Department of Life Science, National Institute of Technology, Rourkela 769008, India
| | - Amit Mishra
- Cellular and Molecular Neurobiology Unit, Indian Institute of Technology Jodhpur, Jodhpur 342037, India
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59
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Hagan MF, Mohajerani F. Self-assembly coupled to liquid-liquid phase separation. PLoS Comput Biol 2023; 19:e1010652. [PMID: 37186597 PMCID: PMC10212142 DOI: 10.1371/journal.pcbi.1010652] [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: 10/12/2022] [Revised: 05/25/2023] [Accepted: 04/26/2023] [Indexed: 05/17/2023] Open
Abstract
Liquid condensate droplets with distinct compositions of proteins and nucleic acids are widespread in biological cells. While it is known that such droplets, or compartments, can regulate irreversible protein aggregation, their effect on reversible self-assembly remains largely unexplored. In this article, we use kinetic theory and solution thermodynamics to investigate the effect of liquid-liquid phase separation on the reversible self-assembly of structures with well-defined sizes and architectures. We find that, when assembling subunits preferentially partition into liquid compartments, robustness against kinetic traps and maximum achievable assembly rates can be significantly increased. In particular, both the range of solution conditions leading to productive assembly and the corresponding assembly rates can increase by orders of magnitude. We analyze the rate equation predictions using simple scaling estimates to identify effects of liquid-liquid phase separation as a function of relevant control parameters. These results may elucidate self-assembly processes that underlie normal cellular functions or pathogenesis, and suggest strategies for designing efficient bottom-up assembly for nanomaterials applications.
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Affiliation(s)
- Michael F. Hagan
- Martin A. Fisher School of Physics, Brandeis University, Waltham, Massachusetts, United States of America
| | - Farzaneh Mohajerani
- Martin A. Fisher School of Physics, Brandeis University, Waltham, Massachusetts, United States of America
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60
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Kang J, Lim L, Song J. ALS-causing hPFN1 mutants differentially disrupt LLPS of FUS prion-like domain. Biochem Biophys Res Commun 2023; 664:35-42. [PMID: 37130459 DOI: 10.1016/j.bbrc.2023.04.101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Accepted: 04/27/2023] [Indexed: 05/04/2023]
Abstract
hPFN1 mutations including C71G cause ALS by gain of toxicity but the mechanism still remains unknown. Stress granules (SGs) are formed by phase separation of the prion-like domain (PLD) of RNA-binding proteins including FUS, whose inclusion was also associated with ALS. C71G-hPFN1 triggers seed-dependent co-aggregation with FUS/TDP-43 to manifest the prion-like propagandation but its biophysical basis remains unexplored. Here by DIC imaging we first showed that three hPFN1 mutants have differential capacity in disrupting the dynamics of liquid droplets formed by phase separation of FUS prion-like domain (PLD). C71G-hPFN1 co-exists with the folded and unfolded states, thus allowing to simultaneously characterize conformations, hydrodynamics and dynamics of the interactions of both states with the phase separated FUS PLD by NMR. The results reveal that the folded state is not significantly affected while by contrast, the unfolded state has extensive interactions with FUS PLD. As a consequence, the dynamics of FUS liquid droplets become significantly reduced. Such interactions might act to recruit C71G-hPFN1 into the droplets, thus leading to the increase of the local concentrations and subsequent co-aggregation of C71G-hPFN1 with FUS. Our study sheds the first light on the biophysical basis by which hPFN1 mutants gain toxicity to cause ALS. As other aggregation-prone proteins have no fundamental difference from hPFN1 mutants, aggregation-prone proteins might share a common capacity in disrupting phase separation responsible for organizing various membrane-less organelles. As such, the mechanism for C71G-hPFN1 might also be utilized by other aggregation-prone proteins for gain of toxicity to trigger diseases and aging.
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Affiliation(s)
- Jian Kang
- Department of Biological Sciences, Faculty of Science, National University of Singapore, 10 Kent Ridge Crescent, 119260, Singapore
| | - Liangzhong Lim
- Department of Biological Sciences, Faculty of Science, National University of Singapore, 10 Kent Ridge Crescent, 119260, Singapore
| | - Jianxing Song
- Department of Biological Sciences, Faculty of Science, National University of Singapore, 10 Kent Ridge Crescent, 119260, Singapore.
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Kassouf T, Shrivastava R, Meszka I, Bailly A, Polanowska J, Trauchessec H, Mandrioli J, Carra S, Xirodimas DP. Targeting the NEDP1 enzyme to ameliorate ALS phenotypes through stress granule disassembly. SCIENCE ADVANCES 2023; 9:eabq7585. [PMID: 37000881 PMCID: PMC10065448 DOI: 10.1126/sciadv.abq7585] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Accepted: 02/27/2023] [Indexed: 06/19/2023]
Abstract
The elimination of aberrant inclusions is regarded as a therapeutic approach in neurodegeneration. In amyotrophic lateral sclerosis (ALS), mutations in proteins found within cytoplasmic condensates called stress granules (SGs) are linked to the formation of pathological SGs, aberrant protein inclusions, and neuronal toxicity. We found that inhibition of NEDP1, the enzyme that processes/deconjugates the ubiquitin-like molecule NEDD8, promotes the disassembly of physiological and pathological SGs. Reduction in poly(ADP-ribose) polymerase1 activity through hyper-NEDDylation is a key mechanism for the observed phenotype. These effects are related to improved cell survival in human cells, and in C. elegans, nedp1 deletion ameliorates ALS phenotypes related to animal motility. Our studies reveal NEDP1 as potential therapeutic target for ALS, correlated to the disassembly of pathological SGs.
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Affiliation(s)
| | | | - Igor Meszka
- CRBM, Univ. Montpellier, CNRS, Montpellier, France
| | | | | | | | - Jessica Mandrioli
- Neurology Unit, Azienda Ospedaliero Universitaria di Modena, 41126 Modena, Italy
- Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia,G. Campi 287, 41125 Modena, Italy
| | - Serena Carra
- Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia,G. Campi 287, 41125 Modena, Italy
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62
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Kohler V, Andréasson C. Reversible protein assemblies in the proteostasis network in health and disease. Front Mol Biosci 2023; 10:1155521. [PMID: 37021114 PMCID: PMC10067754 DOI: 10.3389/fmolb.2023.1155521] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Accepted: 03/09/2023] [Indexed: 04/07/2023] Open
Abstract
While proteins populating their native conformations constitute the functional entities of cells, protein aggregates are traditionally associated with cellular dysfunction, stress and disease. During recent years, it has become clear that large aggregate-like protein condensates formed via liquid-liquid phase separation age into more solid aggregate-like particles that harbor misfolded proteins and are decorated by protein quality control factors. The constituent proteins of the condensates/aggregates are disentangled by protein disaggregation systems mainly based on Hsp70 and AAA ATPase Hsp100 chaperones prior to their handover to refolding and degradation systems. Here, we discuss the functional roles that condensate formation/aggregation and disaggregation play in protein quality control to maintain proteostasis and why it matters for understanding health and disease.
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Affiliation(s)
- Verena Kohler
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Claes Andréasson
- Department of Molecular Biosciences, Stockholm University, Stockholm, Sweden
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63
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Xing F, Qin Y, Xu J, Wang W, Zhang B. Stress granules dynamics and promising functions in pancreatic cancer. Biochim Biophys Acta Rev Cancer 2023; 1878:188885. [PMID: 36990249 DOI: 10.1016/j.bbcan.2023.188885] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 02/14/2023] [Accepted: 02/23/2023] [Indexed: 03/30/2023]
Abstract
Stress granules (SGs), non-membrane subcellular organelles made up of non-translational messenger ribonucleoproteins (mRNPs), assemble in response to various environmental stimuli in cancer cells, including pancreatic cancer, particularly pancreatic ductal adenocarcinoma (PDAC) which has a low 5-year survival rate of 10%. The pertinent research on SGs and pancreatic cancer has not, however, been compiled. In this review, we talk about the dynamics of SGs and their positive effects on pancreatic cancer such as SGs promote PDAC viability and repress apoptosis, meanwhile emphasizing the connection between SGs in pancreatic cancer and signature mutations such KRAS, P53, and SMAD4 as well as the functions of SGs in antitumor drug resistance. This novel stress management technique may open the door to better treatment options in the future.
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64
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Tedesco B, Vendredy L, Adriaenssens E, Cozzi M, Asselbergh B, Crippa V, Cristofani R, Rusmini P, Ferrari V, Casarotto E, Chierichetti M, Mina F, Pramaggiore P, Galbiati M, Piccolella M, Baets J, Baeke F, De Rycke R, Mouly V, Laurenzi T, Eberini I, Vihola A, Udd B, Weiss L, Kimonis V, Timmerman V, Poletti A. HSPB8 frameshift mutant aggregates weaken chaperone-assisted selective autophagy in neuromyopathies. Autophagy 2023:1-23. [PMID: 36854646 DOI: 10.1080/15548627.2023.2179780] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/02/2023] Open
Abstract
Chaperone-assisted selective autophagy (CASA) is a highly selective pathway for the disposal of misfolding and aggregating proteins. In muscle, CASA assures muscle integrity by favoring the turnover of structural components damaged by mechanical strain. In neurons, CASA promotes the removal of aggregating substrates. A crucial player of CASA is HSPB8 (heat shock protein family B (small) member 8), which acts in a complex with HSPA, their cochaperone BAG3, and the E3 ubiquitin ligase STUB1. Recently, four novel HSPB8 frameshift (fs) gene mutations have been linked to neuromyopathies, and encode carboxy-terminally mutated HSPB8, sharing a common C-terminal extension. Here, we analyzed the biochemical and functional alterations associated with the HSPB8_fs mutant proteins. We demonstrated that HSPB8_fs mutants are highly insoluble and tend to form proteinaceous aggregates in the cytoplasm. Notably, all HSPB8 frameshift mutants retain their ability to interact with CASA members but sequester them into the HSPB8-positive aggregates together with two autophagy receptors SQSTM1/p62 and TAX1BP1. This copartitioning process negatively affects the CASA capability to remove its clients and causes a general failure in proteostasis response. Further analyses revealed that the aggregation of the HSPB8_fs mutants occurs independently of the other CASA members or from the autophagy receptors interaction, but it is an intrinsic feature of the mutated amino acid sequence. HSPB8_fs mutants aggregation alters the differentiation capacity of muscle cells and impairs sarcomere organization. Collectively, these results shed light on a potential pathogenic mechanism shared by the HSPB8_fs mutants described in neuromuscular diseases.Abbreviations : ACD: α-crystallin domain; ACTN: actinin alpha; BAG3: BAG cochaperone 3; C: carboxy; CASA: chaperone-assisted selective autophagy; CE: carboxy-terminal extension; CLEM: correlative light and electron microscopy; CMT2L: Charcot-Marie-Tooth type 2L; CTR: carboxy-terminal region; dHMNII: distal hereditary motor neuropathy type II; EV: empty vector; FRA: filter retardation assay; fs: frameshift; HSPA/HSP70: heat shock protein family A (Hsp70); HSPB1/Hsp27: heat shock protein family B (small) member 1; HSPB8/Hsp22: heat shock protein family B (small) member 8; HTT: huntingtin; KO: knockout; MAP1LC3B/LC3: microtubule associated protein 1 light chain 3 beta; MD: molecular dynamics; MTOC: microtubule organizing center; MYH: myosin heavy chain; MYOG: myogenin; NBR1: NBR1 autophagy cargo receptor; CALCOCO2/NDP52: calcium binding and coiled-coil domain 2; NSC34: Neuroblastoma X Spinal Cord 34; OPTN: optineurin; polyQ: polyglutamine; SQSTM1/p62: sequestosome 1; STUB1/CHIP: STIP1 homology and U-box containing protein 1; TARDBP/TDP-43: TAR DNA binding protein; TAX1BP1: Tax1 binding protein 1; TUBA: tubulin alpha; WT: wild-type.
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Affiliation(s)
- Barbara Tedesco
- Dipartimento di Scienze Farmacologiche e Biomolecolari "Rodolfo Paoletti", Dipartimento di Eccellenza 2018-2027, Università degli Studi di Milano, Milan, Italy.,Unit of Medical Genetics and Neurogenetics, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Leen Vendredy
- Peripheral Neuropathy Research Group, Department of Biomedical Sciences and Institute Born Bunge, University of Antwerp, Antwerpen, Belgium
| | - Elias Adriaenssens
- Peripheral Neuropathy Research Group, Department of Biomedical Sciences and Institute Born Bunge, University of Antwerp, Antwerpen, Belgium
| | - Marta Cozzi
- Dipartimento di Scienze Farmacologiche e Biomolecolari "Rodolfo Paoletti", Dipartimento di Eccellenza 2018-2027, Università degli Studi di Milano, Milan, Italy
| | - Bob Asselbergh
- Neuromics Support Facility, VIB Center for Molecular Neurology, VIB, Antwerp, Belgium.,Neuromics Support Facility, Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium
| | - Valeria Crippa
- Dipartimento di Scienze Farmacologiche e Biomolecolari "Rodolfo Paoletti", Dipartimento di Eccellenza 2018-2027, Università degli Studi di Milano, Milan, Italy
| | - Riccardo Cristofani
- Dipartimento di Scienze Farmacologiche e Biomolecolari "Rodolfo Paoletti", Dipartimento di Eccellenza 2018-2027, Università degli Studi di Milano, Milan, Italy
| | - Paola Rusmini
- Dipartimento di Scienze Farmacologiche e Biomolecolari "Rodolfo Paoletti", Dipartimento di Eccellenza 2018-2027, Università degli Studi di Milano, Milan, Italy
| | - Veronica Ferrari
- Dipartimento di Scienze Farmacologiche e Biomolecolari "Rodolfo Paoletti", Dipartimento di Eccellenza 2018-2027, Università degli Studi di Milano, Milan, Italy
| | - Elena Casarotto
- Dipartimento di Scienze Farmacologiche e Biomolecolari "Rodolfo Paoletti", Dipartimento di Eccellenza 2018-2027, Università degli Studi di Milano, Milan, Italy
| | - Marta Chierichetti
- Dipartimento di Scienze Farmacologiche e Biomolecolari "Rodolfo Paoletti", Dipartimento di Eccellenza 2018-2027, Università degli Studi di Milano, Milan, Italy
| | - Francesco Mina
- Dipartimento di Scienze Farmacologiche e Biomolecolari "Rodolfo Paoletti", Dipartimento di Eccellenza 2018-2027, Università degli Studi di Milano, Milan, Italy
| | - Paola Pramaggiore
- Dipartimento di Scienze Farmacologiche e Biomolecolari "Rodolfo Paoletti", Dipartimento di Eccellenza 2018-2027, Università degli Studi di Milano, Milan, Italy
| | - Mariarita Galbiati
- Dipartimento di Scienze Farmacologiche e Biomolecolari "Rodolfo Paoletti", Dipartimento di Eccellenza 2018-2027, Università degli Studi di Milano, Milan, Italy
| | - Margherita Piccolella
- Dipartimento di Scienze Farmacologiche e Biomolecolari "Rodolfo Paoletti", Dipartimento di Eccellenza 2018-2027, Università degli Studi di Milano, Milan, Italy
| | - Jonathan Baets
- Laboratory of Neuromuscular Pathology, Institute Born Bunge, and Translational Neurosciences, Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium.,Neuromuscular Reference Centre, Department of Neurology, Antwerp University Hospital, Antwerp, Belgium
| | - Femke Baeke
- Department of Biomedical Molecular Biology, and VIB Center for Inflammation Research, and VIB Bioimaging Core, Ghent University Ghent, Belgium
| | - Riet De Rycke
- Department of Biomedical Molecular Biology, and VIB Center for Inflammation Research, and VIB Bioimaging Core, Ghent University Ghent, Belgium
| | - Vincent Mouly
- Sorbonne Université, Inserm, Institut de Myologie, Centre de Recherche en Myologie, Paris, France
| | - Tommaso Laurenzi
- Dipartimento di Scienze Farmacologiche e Biomolecolari "Rodolfo Paoletti", Dipartimento di Eccellenza 2018-2027, Università degli Studi di Milano, Milan, Italy
| | - Ivano Eberini
- Dipartimento di Scienze Farmacologiche e Biomolecolari "Rodolfo Paoletti", Dipartimento di Eccellenza 2018-2027, Università degli Studi di Milano, Milan, Italy
| | - Anna Vihola
- Folkhälsan Research Center, University of Helsinki, Helsinki, Finland.,Neuromuscular Research Center, Tampere University Hospital, Tampere, Finland
| | - Bjarne Udd
- Folkhälsan Research Center, University of Helsinki, Helsinki, Finland.,Neuromuscular Research Center, Tampere University Hospital, Tampere, Finland.,Vasa Central Hospital, Vasa, Finland
| | - Lan Weiss
- Department of Pediatrics, University of California, Irvine, Lombardy, United States
| | - Virginia Kimonis
- Department of Pediatrics, University of California, Irvine, Lombardy, United States
| | - Vincent Timmerman
- Peripheral Neuropathy Research Group, Department of Biomedical Sciences and Institute Born Bunge, University of Antwerp, Antwerpen, Belgium
| | - Angelo Poletti
- Dipartimento di Scienze Farmacologiche e Biomolecolari "Rodolfo Paoletti", Dipartimento di Eccellenza 2018-2027, Università degli Studi di Milano, Milan, Italy
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65
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Szewczyk B, Günther R, Japtok J, Frech MJ, Naumann M, Lee HO, Hermann A. FUS ALS neurons activate major stress pathways and reduce translation as an early protective mechanism against neurodegeneration. Cell Rep 2023; 42:112025. [PMID: 36696267 DOI: 10.1016/j.celrep.2023.112025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 11/02/2022] [Accepted: 01/06/2023] [Indexed: 01/26/2023] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder causing progressive loss of motor neurons. Mutations in Fused in sarcoma (FUS) leading to its cytoplasmic mislocalization cause a subset of ALS. Under stress, mutant FUS localizes to stress granules (SGs)-cytoplasmic condensates composed of RNA and various proteins. Aberrant dynamics of SGs is linked to the pathology of ALS. Here, using motor neurons (MNs) derived from human induced pluripotent stem cells, we show that, in mutant FUS, MN dynamics of SGs is disturbed. Additionally, heat-shock response (HSR) and integrated stress response (ISR) involved in the regulation of SGs are upregulated in mutant MNs. HSR activation correlates with the amount of cytoplasmic FUS mislocalization. While inhibition of SG formation, translation, or ISR does not influence survival of FUS ALS neurons, proteotoxicity that cannot be compensated with the activation of stress pathways is the main driver of neurodegeneration in early FUS ALS.
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Affiliation(s)
- Barbara Szewczyk
- Translational Neurodegeneration Section "Albrecht Kossel", Department of Neurology, University Medical Center Rostock, University of Rostock, Rostock, Germany
| | - René Günther
- Department of Neurology, Technische Universität Dresden, Dresden, Germany; Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE) Dresden, Dresden, Germany
| | - Julia Japtok
- Department of Neurology, Technische Universität Dresden, Dresden, Germany
| | - Moritz J Frech
- Translational Neurodegeneration Section "Albrecht Kossel", Department of Neurology, University Medical Center Rostock, University of Rostock, Rostock, Germany
| | - Marcel Naumann
- Translational Neurodegeneration Section "Albrecht Kossel", Department of Neurology, University Medical Center Rostock, University of Rostock, Rostock, Germany
| | - Hyun O Lee
- Department of Biochemistry, Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - Andreas Hermann
- Translational Neurodegeneration Section "Albrecht Kossel", Department of Neurology, University Medical Center Rostock, University of Rostock, Rostock, Germany; Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE) Rostock/Greifswald, Rostock, Germany; Center for Transdisciplinary Neurosciences Rostock (CTNR), University Medical Center Rostock, University of Rostock, Rostock, Germany.
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66
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Xu S, Gierisch ME, Schellhaus AK, Poser I, Alberti S, Salomons FA, Dantuma NP. Cytosolic stress granules relieve the ubiquitin-proteasome system in the nuclear compartment. EMBO J 2023; 42:e111802. [PMID: 36574355 PMCID: PMC9890234 DOI: 10.15252/embj.2022111802] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 11/25/2022] [Accepted: 12/01/2022] [Indexed: 12/28/2022] Open
Abstract
The role of cytosolic stress granules in the integrated stress response has remained largely enigmatic. Here, we studied the functionality of the ubiquitin-proteasome system (UPS) in cells that were unable to form stress granules. Surprisingly, the inability of cells to form cytosolic stress granules had primarily a negative impact on the functionality of the nuclear UPS. While defective ribosome products (DRiPs) accumulated at stress granules in thermally stressed control cells, they localized to nucleoli in stress granule-deficient cells. The nuclear localization of DRiPs was accompanied by redistribution and enhanced degradation of SUMOylated proteins. Depletion of the SUMO-targeted ubiquitin ligase RNF4, which targets SUMOylated misfolded proteins for proteasomal degradation, largely restored the functionality of the UPS in the nuclear compartment in stress granule-deficient cells. Stress granule-deficient cells showed an increase in the formation of mutant ataxin-1 nuclear inclusions when exposed to thermal stress. Our data reveal that stress granules play an important role in the sequestration of cytosolic misfolded proteins, thereby preventing these proteins from accumulating in the nucleus, where they would otherwise infringe nuclear proteostasis.
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Affiliation(s)
- Shanshan Xu
- Department of Cell and Molecular Biology (CMB)Karolinska InstitutetStockholmSweden
| | - Maria E Gierisch
- Department of Cell and Molecular Biology (CMB)Karolinska InstitutetStockholmSweden
| | | | - Ina Poser
- Max Planck Institute of Molecular Cell Biology and GeneticsDresdenGermany
| | - Simon Alberti
- Max Planck Institute of Molecular Cell Biology and GeneticsDresdenGermany
- Biotechnology Center (BIOTEC), Center for Molecular and Cellular Bioengineering (CMCB)Technische Universität DresdenDresdenGermany
| | - Florian A Salomons
- Department of Cell and Molecular Biology (CMB)Karolinska InstitutetStockholmSweden
| | - Nico P Dantuma
- Department of Cell and Molecular Biology (CMB)Karolinska InstitutetStockholmSweden
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67
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A liquid-to-solid phase transition of Cu/Zn superoxide dismutase 1 initiated by oxidation and disease mutation. J Biol Chem 2023; 299:102857. [PMID: 36592929 PMCID: PMC9898760 DOI: 10.1016/j.jbc.2022.102857] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2022] [Revised: 12/17/2022] [Accepted: 12/19/2022] [Indexed: 01/01/2023] Open
Abstract
Cu/Zn superoxide dismutase 1 (SOD1) has a high propensity to misfold and form abnormal aggregates when it is subjected to oxidative stress or carries mutations associated with amyotrophic lateral sclerosis. However, the transition from functional soluble SOD1 protein to aggregated SOD1 protein is not completely clear. Here, we propose that liquid-liquid phase separation (LLPS) represents a biophysical process that converts soluble SOD1 into aggregated SOD1. We determined that SOD1 undergoes LLPS in vitro and cells under oxidative stress. Abnormal oxidation of SOD1 induces maturation of droplets formed by LLPS, eventually leading to protein aggregation and fibrosis, and involves residues Cys111 and Trp32. Additionally, we found that pathological mutations in SOD1 associated with ALS alter the morphology and material state of the droplets and promote the transformation of SOD1 to solid-like oligomers which are toxic to nerve cells. Furthermore, the fibrous aggregates formed by both pathways have a concentration-dependent toxicity effect on nerve cells. Thus, these combined results strongly indicate that LLPS may play a major role in pathological SOD1 aggregation, contributing to pathogenesis in ALS.
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68
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Phung TH, Tatman M, Monteiro MJ. UBQLN2 undergoes a reversible temperature-induced conformational switch that regulates binding with HSPA1B: ALS/FTD mutations cripple the switch but do not destroy HSPA1B binding. Biochim Biophys Acta Gen Subj 2023; 1867:130284. [PMID: 36423739 PMCID: PMC9792439 DOI: 10.1016/j.bbagen.2022.130284] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 10/23/2022] [Accepted: 11/18/2022] [Indexed: 11/23/2022]
Abstract
Here we present evidence, based on alterations of its intrinsic tryptophan fluorescence, that UBQLN2 protein undergoes a conformational switch when the temperature is raised from 37 °C to 42 °C. The switch is reset on restoration of the temperature. We speculate that the switch regulates UBQLN2 function in the heat shock response because elevation of the temperature from 37 °C to 42 °C dramatically increased in vitro binding between UBQLN2 and HSPA1B. Furthermore, restoration of the temperature to 37 °C decreased HSPA1B binding. By comparison to wild type (WT) UBQLN2, we found that all five ALS/FTD mutant UBQLN2 proteins we examined had attenuated alterations in tryptophan fluorescence when shifted to 42 °C, suggesting that the conformational switch is crippled in the mutants. Paradoxically, all five mutants bound similar amounts of HSPA1B compared to WT UBQLN2 protein at 42 °C, suggesting that either the conformational switch is not instrumental for HSPA1B binding, or that, although damaged, it is still functional. Comparison of the poly-ubiquitin chain binding revealed that WT UBQLN2 binds more avidly with K63 than with K48 chains. The avidity may explain the involvement of UBQLN2 in autophagy and cell signaling. Consistent with its function in autophagy, we found UBQLN2 binds directly with LC3, the autophagosomal-specific membrane-tethered protein. Finally, we provide evidence that WT UBQLN2 can homodimerize, and heterodimerize with WT UBQLN1. We show that ALS mutant P497S-UBQLN2 protein can oligomerize with either WT UBQLN1 or 2, providing a possible mechanism for how mutant UBQLN2 proteins could bind and inactivate UBQLN proteins, causing loss of function.
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Affiliation(s)
- Trong H Phung
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD, USA; Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Micaela Tatman
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD, USA; Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Mervyn J Monteiro
- Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD, USA; Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD, USA.
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69
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Metamorphism in TDP-43 prion-like domain determines chaperone recognition. Nat Commun 2023; 14:466. [PMID: 36709343 PMCID: PMC9884275 DOI: 10.1038/s41467-023-36023-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Accepted: 01/12/2023] [Indexed: 01/29/2023] Open
Abstract
The RNA binding protein TDP-43 forms cytoplasmic inclusions via its C-terminal prion-like domain in several neurodegenerative diseases. Aberrant TDP-43 aggregation arises upon phase de-mixing and transitions from liquid to solid states, following still unknown structural conversions which are primed by oxidative stress and chaperone inhibition. Despite the well-established protective roles for molecular chaperones against protein aggregation pathologies, knowledge on the determinants of chaperone recognition in disease-related prions is scarce. Here we show that chaperones and co-chaperones primarily recognize the structured elements in TDP-43´s prion-like domain. Significantly, while HSP70 and HSP90 chaperones promote TDP-43 phase separation, co-chaperones from the three classes of the large human HSP40 family (namely DNAJA2, DNAJB1, DNAJB4 and DNAJC7) show strikingly different effects on TDP-43 de-mixing. Dismantling of the second helical element in TDP-43 prion-like domain by methionine sulfoxidation impacts phase separation and amyloid formation, abrogates chaperone recognition and alters phosphorylation by casein kinase-1δ. Our results show that metamorphism in the post-translationally modified TDP-43 prion-like domain encodes determinants that command mechanisms with major relevance in disease.
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70
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Millar SR, Huang JQ, Schreiber KJ, Tsai YC, Won J, Zhang J, Moses AM, Youn JY. A New Phase of Networking: The Molecular Composition and Regulatory Dynamics of Mammalian Stress Granules. Chem Rev 2023. [PMID: 36662637 PMCID: PMC10375481 DOI: 10.1021/acs.chemrev.2c00608] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Stress granules (SGs) are cytosolic biomolecular condensates that form in response to cellular stress. Weak, multivalent interactions between their protein and RNA constituents drive their rapid, dynamic assembly through phase separation coupled to percolation. Though a consensus model of SG function has yet to be determined, their perceived implication in cytoprotective processes (e.g., antiviral responses and inhibition of apoptosis) and possible role in the pathogenesis of various neurodegenerative diseases (e.g., amyotrophic lateral sclerosis and frontotemporal dementia) have drawn great interest. Consequently, new studies using numerous cell biological, genetic, and proteomic methods have been performed to unravel the mechanisms underlying SG formation, organization, and function and, with them, a more clearly defined SG proteome. Here, we provide a consensus SG proteome through literature curation and an update of the user-friendly database RNAgranuleDB to version 2.0 (http://rnagranuledb.lunenfeld.ca/). With this updated SG proteome, we use next-generation phase separation prediction tools to assess the predisposition of SG proteins for phase separation and aggregation. Next, we analyze the primary sequence features of intrinsically disordered regions (IDRs) within SG-resident proteins. Finally, we review the protein- and RNA-level determinants, including post-translational modifications (PTMs), that regulate SG composition and assembly/disassembly dynamics.
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Affiliation(s)
- Sean R Millar
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Jie Qi Huang
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Karl J Schreiber
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada
| | - Yi-Cheng Tsai
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Jiyun Won
- Department of Cell & Systems Biology, University of Toronto, Toronto, Ontario M5S 3B2, Canada
| | - Jianping Zhang
- Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, Ontario M5G 1X5, Canada
| | - Alan M Moses
- Department of Cell & Systems Biology, University of Toronto, Toronto, Ontario M5S 3B2, Canada.,Department of Computer Science, University of Toronto, Toronto, Ontario M5T 3A1, Canada.,The Centre for the Analysis of Genome Evolution and Function, University of Toronto, Toronto, Ontario M5S 3B2, Canada
| | - Ji-Young Youn
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5S 1A8, Canada.,Program in Molecular Medicine, The Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada
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71
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Das B, Roychowdhury S, Mohanty P, Rizuan A, Chakraborty J, Mittal J, Chattopadhyay K. A Zn-dependent structural transition of SOD1 modulates its ability to undergo phase separation. EMBO J 2023; 42:e111185. [PMID: 36416085 PMCID: PMC9841336 DOI: 10.15252/embj.2022111185] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Revised: 10/26/2022] [Accepted: 10/31/2022] [Indexed: 11/24/2022] Open
Abstract
The misfolding and mutation of Cu/Zn superoxide dismutase (SOD1) is commonly associated with amyotrophic lateral sclerosis (ALS). SOD1 can accumulate within stress granules (SGs), a type of membraneless organelle, which is believed to form via liquid-liquid phase separation (LLPS). Using wild-type, metal-deficient, and different ALS disease mutants of SOD1 and computer simulations, we report here that the absence of Zn leads to structural disorder within two loop regions of SOD1, triggering SOD1 LLPS and amyloid formation. The addition of exogenous Zn to either metal-free SOD1 or to the severe ALS mutation I113T leads to the stabilization of the loops and impairs SOD1 LLPS and aggregation. Moreover, partial Zn-mediated inhibition of LLPS was observed for another severe ALS mutant, G85R, which shows perturbed Zn-binding. By contrast, the ALS mutant G37R, which shows reduced Cu-binding, does not undergo LLPS. In addition, SOD1 condensates induced by Zn-depletion exhibit greater cellular toxicity than aggregates formed by prolonged incubation under aggregating conditions. Overall, our work establishes a role for Zn-dependent modulation of SOD1 conformation and LLPS properties that may contribute to amyloid formation.
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Affiliation(s)
- Bidisha Das
- Structural Biology and Bioinformatics DivisionCSIR‐Indian Institute of Chemical BiologyKolkataIndia
- Academy of Scientific and Innovative Research (AcSIR)GhaziabadIndia
| | - Sumangal Roychowdhury
- Structural Biology and Bioinformatics DivisionCSIR‐Indian Institute of Chemical BiologyKolkataIndia
| | - Priyesh Mohanty
- Artie McFerrin Department of Chemical EngineeringTexas A&M UniversityCollege StationTXUSA
| | - Azamat Rizuan
- Artie McFerrin Department of Chemical EngineeringTexas A&M UniversityCollege StationTXUSA
| | - Joy Chakraborty
- Cell Biology and Physiology DivisionCSIR‐Indian Institute of Chemical BiologyKolkataIndia
| | - Jeetain Mittal
- Artie McFerrin Department of Chemical EngineeringTexas A&M UniversityCollege StationTXUSA
| | - Krishnananda Chattopadhyay
- Structural Biology and Bioinformatics DivisionCSIR‐Indian Institute of Chemical BiologyKolkataIndia
- Academy of Scientific and Innovative Research (AcSIR)GhaziabadIndia
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72
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Liquid-liquid Phase Separation of α-Synuclein: A New Mechanistic Insight for α-Synuclein Aggregation Associated with Parkinson's Disease Pathogenesis. J Mol Biol 2023; 435:167713. [PMID: 35787838 DOI: 10.1016/j.jmb.2022.167713] [Citation(s) in RCA: 41] [Impact Index Per Article: 41.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2022] [Revised: 06/25/2022] [Accepted: 06/27/2022] [Indexed: 02/04/2023]
Abstract
Aberrant aggregation of the misfolded presynaptic protein, α-Synuclein (α-Syn) into Lewy body (LB) and Lewy neuritis (LN) is a major pathological hallmark of Parkinson's disease (PD) and other synucleinopathies. Numerous studies have suggested that prefibrillar and fibrillar species of the misfolded α-Syn aggregates are responsible for cell death in PD pathogenesis. However, the precise molecular events during α-Syn aggregation, especially in the early stages, remain elusive. Emerging evidence has demonstrated that liquid-liquid phase separation (LLPS) of α-Syn occurs in the nucleation step of α-Syn aggregation, which offers an alternate non-canonical aggregation pathway in the crowded microenvironment. The liquid-like α-Syn droplets gradually undergo an irreversible liquid-to-solid phase transition into amyloid-like hydrogel entrapping oligomers and fibrils. This new mechanism of α-Syn LLPS and gel formation might represent the molecular basis of cellular toxicity associated with PD. This review aims to demonstrate the recent development of α-Syn LLPS, the underlying mechanism along with the microscopic events of aberrant phase transition. This review further discusses how several intrinsic and extrinsic factors regulate the thermodynamics and kinetics of α-Syn LLPS and co-LLPS with other proteins, which might explain the pathophysiology of α-Syn in various neurodegenerative diseases.
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73
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Tedesco B, Vendredy L, Timmerman V, Poletti A. The chaperone-assisted selective autophagy complex dynamics and dysfunctions. Autophagy 2023:1-23. [PMID: 36594740 DOI: 10.1080/15548627.2022.2160564] [Citation(s) in RCA: 21] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Each protein must be synthesized with the correct amino acid sequence, folded into its native structure, and transported to a relevant subcellular location and protein complex. If any of these steps fail, the cell has the capacity to break down aberrant proteins to maintain protein homeostasis (also called proteostasis). All cells possess a set of well-characterized protein quality control systems to minimize protein misfolding and the damage it might cause. Autophagy, a conserved pathway for the degradation of long-lived proteins, aggregates, and damaged organelles, was initially characterized as a bulk degradation pathway. However, it is now clear that autophagy also contributes to intracellular homeostasis by selectively degrading cargo material. One of the pathways involved in the selective removal of damaged and misfolded proteins is chaperone-assisted selective autophagy (CASA). The CASA complex is composed of three main proteins (HSPA, HSPB8 and BAG3), essential to maintain protein homeostasis in muscle and neuronal cells. A failure in the CASA complex, caused by mutations in the respective coding genes, can lead to (cardio)myopathies and neurodegenerative diseases. Here, we summarize our current understanding of the CASA complex and its dynamics. We also briefly discuss how CASA complex proteins are involved in disease and may represent an interesting therapeutic target.Abbreviation ALP: autophagy lysosomal pathway; ALS: amyotrophic lateral sclerosis; AMOTL1: angiomotin like 1; ARP2/3: actin related protein 2/3; BAG: BAG cochaperone; BAG3: BAG cochaperone 3; CASA: chaperone-assisted selective autophagy; CMA: chaperone-mediated autophagy; DNAJ/HSP40: DnaJ heat shock protein family (Hsp40); DRiPs: defective ribosomal products; EIF2A/eIF2α: eukaryotic translation initiation factor 2A; EIF2AK1/HRI: eukaryotic translation initiation factor 2 alpha kinase 1; GABARAP: GABA type A receptor-associated protein; HDAC6: histone deacetylase 6; HSP: heat shock protein; HSPA/HSP70: heat shock protein family A (Hsp70); HSP90: heat shock protein 90; HSPB8: heat shock protein family B (small) member 8; IPV: isoleucine-proline-valine; ISR: integrated stress response; KEAP1: kelch like ECH associated protein 1; LAMP2A: lysosomal associated membrane protein 2A; LATS1: large tumor suppressor kinase 1; LIR: LC3-interacting region; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MTOC: microtubule organizing center; MTOR: mechanistic target of rapamycin kinase; NFKB/NF-κB: nuclear factor kappa B; NFE2L2: NFE2 like bZIP transcription factor 2; PLCG/PLCγ: phospholipase C gamma; polyQ: polyglutamine; PQC: protein quality control; PxxP: proline-rich; RAN translation: repeat-associated non-AUG translation; SG: stress granule; SOD1: superoxide dismutase 1; SQSTM1/p62: sequestosome 1; STUB1/CHIP: STIP1 homology and U-box containing protein 1; STK: serine/threonine kinase; SYNPO: synaptopodin; TBP: TATA-box binding protein; TARDBP/TDP-43: TAR DNA binding protein; TFEB: transcription factor EB; TPR: tetratricopeptide repeats; TSC1: TSC complex subunit 1; UBA: ubiquitin associated; UPS: ubiquitin-proteasome system; WW: tryptophan-tryptophan; WWTR1: WW domain containing transcription regulator 1; YAP1: Yes1 associated transcriptional regulator.
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Affiliation(s)
- Barbara Tedesco
- Laboratory of Experimental Biology, Dipartimento di Scienze Farmacologiche e Biomolecolari, Dipartimento di Eccellenza 2018-2027, Università degli studi di Milano, Milan, Italy.,Unit of Medical Genetics and Neurogenetics, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Leen Vendredy
- Peripheral Neuropathy Research Group, Department of Biomedical Sciences, Institute Born Bunge, University of Antwerp, Antwerpen, Belgium
| | - Vincent Timmerman
- Peripheral Neuropathy Research Group, Department of Biomedical Sciences, Institute Born Bunge, University of Antwerp, Antwerpen, Belgium
| | - Angelo Poletti
- Laboratory of Experimental Biology, Dipartimento di Scienze Farmacologiche e Biomolecolari, Dipartimento di Eccellenza 2018-2027, Università degli studi di Milano, Milan, Italy
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74
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Pönisch W, Michaels TCT, Weber CA. Aggregation controlled by condensate rheology. Biophys J 2023; 122:197-214. [PMID: 36369755 PMCID: PMC9822804 DOI: 10.1016/j.bpj.2022.11.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 06/12/2022] [Accepted: 11/04/2022] [Indexed: 11/13/2022] Open
Abstract
Biomolecular condensates in living cells can exhibit a complex rheology, including viscoelastic and glassy behavior. This rheological behavior of condensates was suggested to regulate polymerization of cytoskeletal filaments and aggregation of amyloid fibrils. Here, we theoretically investigate how the rheological properties of condensates can control the formation of linear aggregates. To this end, we propose a kinetic theory for linear aggregation in coexisting phases, which accounts for the aggregate size distribution and the exchange of aggregates between inside and outside of condensates. The rheology of condensates is accounted in our model via aggregate mobilities that depend on aggregate size. We show that condensate rheology determines whether aggregates of all sizes or dominantly small aggregates are exchanged between condensate inside and outside on the timescale of aggregation. As a result, the ratio of aggregate numbers inside to outside of condensates differs significantly. Strikingly, we also find that weak variations in the rheological properties of condensates can lead to a switch-like change of the number of aggregates. These results suggest a possible physical mechanism for how living cells could control linear aggregation in a switch-like fashion through variations in condensate rheology.
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Affiliation(s)
- Wolfram Pönisch
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
| | - Thomas C T Michaels
- Laboratory for Molecular Cell Biology, University College London, London, United Kingdom; Medical Research Council Laboratory for Molecular Cell Biology, University College London, London, United Kingdom; Department of Biology, Institute of Biochemistry, ETH Zurich, Zurich, Switzerland.
| | - Christoph A Weber
- Max Planck Institute for the Physics of Complex Systems, Dresden, Germany; Center for Systems Biology Dresden, Dresden, Germany; Faculty of Mathematics, Natural Sciences, and Materials Engineering, Institute of Physics, University of Augsburg, Augsburg, Germany.
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75
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Chierichetti M, Cerretani M, Ciammaichella A, Crippa V, Rusmini P, Ferrari V, Tedesco B, Casarotto E, Cozzi M, Mina F, Pramaggiore P, Galbiati M, Piccolella M, Bresciani A, Cristofani R, Poletti A. Identification of HSPB8 modulators counteracting misfolded protein accumulation in neurodegenerative diseases. Life Sci 2022; 322:121323. [PMID: 36574942 DOI: 10.1016/j.lfs.2022.121323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 12/17/2022] [Accepted: 12/20/2022] [Indexed: 12/25/2022]
Abstract
AIMS The small Heat Shock Protein B8 (HSPB8) is the core component of the chaperone-assisted selective autophagy (CASA) complex. This complex selectively targets, transports, and tags misfolded proteins for their recognition by autophagic receptors and insertion into autophagosome for clearance. CASA is essential to maintain intracellular proteostasis, especially in heart, muscle, and brain often exposed to various types of cell stresses. In neurons, HSPB8 protects against neurotoxicity caused by misfolded proteins in several models of neurodegenerative diseases; by facilitating autophagy, HSPB8 assists misfolded protein degradation also counteracting proteasome overwhelming and inhibition. MATERIALS AND METHODS To enhance HSPB8 protective activity, we screened a library of approximately 120,000 small molecules to identify compounds capable of increasing HSPB8 gene transcription, translation, or protein stability. We found 83 compounds active in preliminary dose-response assays and further classified them in 19 chemical classes by medicinal chemists' visual inspection. Of these 19 prototypes, 14 induced HSPB8 mRNA and protein levels in SH-SY5Y cells. KEY FINDINGS Out of these 14, 3 successfully reduced the aggregation propensity of a disease-associated mutant misfolded Superoxide Dismutase 1 (SOD1) protein in a flow cytometry-based "aggregation assay" [Flow cytometric analysis of Inclusions and Trafficking" (FloIT)] and induced the expression (mRNA and protein) of some autophagy receptors. Notably, the 3 hits were inactive in HSPB8-depleted cells, confirming that their protective activity is mediated by and requires HSPB8. SIGNIFICANCE Thus, these compounds may be highly relevant for a therapeutic approach in several human disorders, including neurodegenerative diseases, in which enhancement of CASA exerts beneficial activities.
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Affiliation(s)
- Marta Chierichetti
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milan, Italy
| | - Mauro Cerretani
- Department of Translational and Discovery Research, IRBM S.p.A., Via Pontina Km 30,600, 00071 Pomezia, Roma, Italy
| | - Alina Ciammaichella
- Department of Drug Discovery, IRBM S.p.A., Via Pontina Km 30,600, 00071 Pomezia, Roma, Italy
| | - Valeria Crippa
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milan, Italy
| | - Paola Rusmini
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milan, Italy
| | - Veronica Ferrari
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milan, Italy
| | - Barbara Tedesco
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milan, Italy; Unit of Medical Genetics and Neurogenetics, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Elena Casarotto
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milan, Italy
| | - Marta Cozzi
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milan, Italy
| | - Francesco Mina
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milan, Italy
| | - Paola Pramaggiore
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milan, Italy
| | - Mariarita Galbiati
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milan, Italy
| | - Margherita Piccolella
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milan, Italy
| | - Alberto Bresciani
- Department of Translational and Discovery Research, IRBM S.p.A., Via Pontina Km 30,600, 00071 Pomezia, Roma, Italy
| | - Riccardo Cristofani
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milan, Italy.
| | - Angelo Poletti
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milan, Italy.
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76
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Nogami M, Sano O, Adachi-Tominari K, Hayakawa-Yano Y, Furukawa T, Iwata H, Ogi K, Okano H, Yano M. DNA damage stress-induced translocation of mutant FUS proteins into cytosolic granules and screening for translocation inhibitors. Front Mol Neurosci 2022; 15:953365. [PMID: 36606141 PMCID: PMC9808394 DOI: 10.3389/fnmol.2022.953365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Accepted: 11/30/2022] [Indexed: 12/24/2022] Open
Abstract
Fused in sarcoma/translated in liposarcoma (FUS) is an RNA-binding protein, and its mutations are associated with neurodegenerative diseases, including amyotrophic lateral sclerosis (ALS), through the DNA damage stress response, aberrant stress granule (SG) formation, etc. We previously reported that translocation of endogenous FUS into SGs was achieved by cotreatment with a DNA double-strand break inducer and an inhibitor of DNA-PK activity. In the present study, we investigated cytoplasmic SG formation using various fluorescent protein-tagged mutant FUS proteins in a human astrocytoma cell (U251) model. While the synergistic enhancement of the migration of fluorescent protein-tagged wild-type FUS to cytoplasmic SGs upon DNA damage induction was observed when DNA-PK activity was suppressed, the fluorescent protein-tagged FUSP525L mutant showed cytoplasmic localization. It migrated to cytoplasmic SGs upon DNA damage induction alone, and DNA-PK inhibition also showed a synergistic effect. Furthermore, analysis of 12 sites of DNA-PK-regulated phosphorylation in the N-terminal LC region of FUS revealed that hyperphosphorylation of FUS mitigated the mislocalization of FUS into cytoplasmic SGs. By using this cell model, we performed screening of a compound library to identify compounds that inhibit the migration of FUS to cytoplasmic SGs but do not affect the localization of the SG marker molecule G3BP1 to cytoplasmic SGs. Finally, we successfully identified 23 compounds that inhibit FUS-containing SG formation without changing normal SG formation. Highlights Characterization of DNA-PK-dependent FUS stress granule localization.A compound library was screened to identify compounds that inhibit the formation of FUS-containing stress granules.
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Affiliation(s)
- Masahiro Nogami
- Innovative Biology Laboratories, Neuroscience Drug Discovery Unit, Research, Takeda Pharmaceutical Company Limited, Fujisawa, Japan,Shonan Incubation Laboratories, Research, Takeda Pharmaceutical Company Limited, Fujisawa, Japan,*Correspondence: Masahiro Nogami,
| | - Osamu Sano
- Innovative Biology Laboratories, Neuroscience Drug Discovery Unit, Research, Takeda Pharmaceutical Company Limited, Fujisawa, Japan
| | - Keiko Adachi-Tominari
- Innovative Biology Laboratories, Neuroscience Drug Discovery Unit, Research, Takeda Pharmaceutical Company Limited, Fujisawa, Japan
| | - Yoshika Hayakawa-Yano
- Department of Physiology, School of Medicine, Keio University, Tokyo, Japan,Division of Neurobiology and Anatomy, Graduate School of Medical and Dental Sciences, Niigata University, Niigata, Japan
| | - Takako Furukawa
- Division of Neurobiology and Anatomy, Graduate School of Medical and Dental Sciences, Niigata University, Niigata, Japan
| | - Hidehisa Iwata
- Innovative Biology Laboratories, Neuroscience Drug Discovery Unit, Research, Takeda Pharmaceutical Company Limited, Fujisawa, Japan
| | - Kazuhiro Ogi
- Innovative Biology Laboratories, Neuroscience Drug Discovery Unit, Research, Takeda Pharmaceutical Company Limited, Fujisawa, Japan,Shonan Incubation Laboratories, Research, Takeda Pharmaceutical Company Limited, Fujisawa, Japan
| | - Hideyuki Okano
- Department of Physiology, School of Medicine, Keio University, Tokyo, Japan
| | - Masato Yano
- Department of Physiology, School of Medicine, Keio University, Tokyo, Japan,Division of Neurobiology and Anatomy, Graduate School of Medical and Dental Sciences, Niigata University, Niigata, Japan,Masato Yano,
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77
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Martin JL, Dawson SJ, Gale JE. An emerging role for stress granules in neurodegenerative disease and hearing loss. Hear Res 2022; 426:108634. [PMID: 36384053 DOI: 10.1016/j.heares.2022.108634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Revised: 09/20/2022] [Accepted: 10/11/2022] [Indexed: 11/04/2022]
Abstract
Stress granules (SGs) are membrane-less cytosolic assemblies that form in response to stress (e.g., heat, oxidative stress, hypoxia, viral infection and UV). Composed of mRNA, RNA binding proteins and signalling proteins, SGs minimise stress-related damage and promote cell survival. Recent research has shown that the stress granule response is vital to the cochlea's response to stress. However, emerging evidence suggests stress granule dysfunction plays a key role in the pathophysiology of multiple neurodegenerative diseases, several of which present with hearing loss as a symptom. Hearing loss has been identified as the largest potentially modifiable risk factor for dementia. The underlying reason for the link between hearing loss and dementia remains to be established. However, several possible mechanisms have been proposed including a common pathological mechanism. Here we will review the role of SGs in the pathophysiology of neurodegenerative diseases and explore possible links and emerging evidence that they may play an important role in maintenance of hearing and may be a common mechanism underlying age-related hearing loss and dementia.
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Affiliation(s)
- Jack L Martin
- UCL Ear Institute, 332 Gray's Inn Road, London WC1X 8EE, UK
| | - Sally J Dawson
- UCL Ear Institute, 332 Gray's Inn Road, London WC1X 8EE, UK.
| | - Jonathan E Gale
- UCL Ear Institute, 332 Gray's Inn Road, London WC1X 8EE, UK.
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78
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Hu R, Qian B, Li A, Fang Y. Role of Proteostasis Regulation in the Turnover of Stress Granules. Int J Mol Sci 2022; 23:ijms232314565. [PMID: 36498892 PMCID: PMC9741362 DOI: 10.3390/ijms232314565] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 11/16/2022] [Accepted: 11/20/2022] [Indexed: 11/24/2022] Open
Abstract
RNA-binding proteins (RBPs) and RNAs can form dynamic, liquid droplet-like cytoplasmic condensates, known as stress granules (SGs), in response to a variety of cellular stresses. This process is driven by liquid-liquid phase separation, mediated by multivalent interactions between RBPs and RNAs. The formation of SGs allows a temporary suspension of certain cellular activities such as translation of unnecessary proteins. Meanwhile, non-translating mRNAs may also be sequestered and stalled. Upon stress removal, SGs are disassembled to resume the suspended biological processes and restore the normal cell functions. Prolonged stress and disease-causal mutations in SG-associated RBPs can cause the formation of aberrant SGs and/or impair SG disassembly, consequently raising the risk of pathological protein aggregation. The machinery maintaining protein homeostasis (proteostasis) includes molecular chaperones and co-chaperones, the ubiquitin-proteasome system, autophagy, and other components, and participates in the regulation of SG metabolism. Recently, proteostasis has been identified as a major regulator of SG turnover. Here, we summarize new findings on the specific functions of the proteostasis machinery in regulating SG disassembly and clearance, discuss the pathological and clinical implications of SG turnover in neurodegenerative disorders, and point to the unresolved issues that warrant future exploration.
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Affiliation(s)
- Rirong Hu
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201203, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Beituo Qian
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201203, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ang Li
- Guangdong-Hong Kong-Macau Institute of CNS Regeneration, Key Laboratory of CNS Regeneration of Ministry of Education, Jinan University, Guangzhou 510632, China
- Correspondence: (A.L.); (Y.F.); Tel.: +86-21-6858-2510 (Y.F.)
| | - Yanshan Fang
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201203, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- Correspondence: (A.L.); (Y.F.); Tel.: +86-21-6858-2510 (Y.F.)
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79
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Different states and the associated fates of biomolecular condensates. Essays Biochem 2022; 66:849-862. [PMID: 36350032 DOI: 10.1042/ebc20220054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Revised: 09/20/2022] [Accepted: 10/07/2022] [Indexed: 11/11/2022]
Abstract
Abstract
Biomolecular condensates are functional assemblies, which can enrich intrinsically disordered proteins (IDPs) and/or RNAs at concentrations that are orders of magnitude higher than the bulk. In their native functional state, these structures can exist in multiple physical states including liquid-droplet phase, hydrogels, and solid assemblies. On the other hand, an aberrant transition between these physical states can result in loss-of-function or a gain-of-toxic-function. A prime example of such an aberrant transition is droplet aging—a phenomenon where some condensates may progressively transition into less dynamic material states at biologically relevant timescales. In this essay, we review structural and viscoelastic roots of aberrant liquid–solid transitions. Also, we highlight the different checkpoints and experimentally tunable handles, both active (ATP-dependent enzymes, post-translational modifications) and passive (colocalization of RNA molecules), that could alter the material state of assemblies.
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80
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Samanta N, Ruiz‐Blanco YB, Fetahaj Z, Gnutt D, Lantz C, Loo JA, Sanchez‐Garcia E, Ebbinghaus S. Superoxide Dismutase 1 Folding Stability as a Target for Molecular Tweezers in SOD1-Related Amyotrophic Lateral Sclerosis. Chembiochem 2022; 23:e202200396. [PMID: 36083789 PMCID: PMC9828543 DOI: 10.1002/cbic.202200396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 09/09/2022] [Indexed: 01/12/2023]
Abstract
Protein misfolding and aggregation are hallmarks of many severe neurodegenerative diseases including Alzheimer's, Parkinson's and Huntington's disease. As a supramolecular ligand that binds to lysine and arginine residues, the molecular tweezer CLR01 was found to modify the aggregation pathway of disease-relevant proteins in vitro and in vivo with beneficial effects on toxicity. However, the molecular mechanisms of how tweezers exert these effects remain mainly unknown, hampering further drug development. Here, we investigate the modulation mechanism of unfolding and aggregation pathways of SOD1, which are involved in amyotrophic lateral sclerosis (ALS), by CLR01. Using a truncated version of the wildtype SOD1 protein, SOD1bar , we show that CLR01 acts on the first step of the aggregation pathway, the unfolding of the SOD1 monomer. CLR01 increases, by ∼10 °C, the melting temperatures of the A4V and G41D SOD1 mutants, which are commonly observed mutations in familial ALS. Molecular dynamics simulations and binding free energy calculations as well as native mass spectrometry and mutational studies allowed us to identify K61 and K92 as binding sites for the tweezers to mediate the stability increase. The data suggest that the modulation of SOD1 conformational stability is a promising target for future developments of supramolecular ligands against neurodegenerative diseases.
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Affiliation(s)
- Nirnay Samanta
- Institute of Physical and Theoretical ChemistryTU Braunschweig38106BraunschweigGermany,Braunschweig Integrated Centre of Systems Biology (BRICS) 38106BraunschweigGermany
| | - Yasser B. Ruiz‐Blanco
- Computational Biochemistry, Center of Medical BiotechnologyUniversity of Duisburg-Essen45141EssenGermany
| | - Zamira Fetahaj
- Department of Physical Chemistry IIRuhr University44780BochumGermany
| | - David Gnutt
- Institute of Physical and Theoretical ChemistryTU Braunschweig38106BraunschweigGermany,Braunschweig Integrated Centre of Systems Biology (BRICS) 38106BraunschweigGermany,Department of Physical Chemistry IIRuhr University44780BochumGermany
| | - Carter Lantz
- Department of Chemistry and BiochemistryUniversity of California-Los Angeles90095Los Angeles, CAUSA
| | - Joseph A. Loo
- Department of Chemistry and BiochemistryUniversity of California-Los Angeles90095Los Angeles, CAUSA
| | - Elsa Sanchez‐Garcia
- Computational Biochemistry, Center of Medical BiotechnologyUniversity of Duisburg-Essen45141EssenGermany
| | - Simon Ebbinghaus
- Institute of Physical and Theoretical ChemistryTU Braunschweig38106BraunschweigGermany,Braunschweig Integrated Centre of Systems Biology (BRICS) 38106BraunschweigGermany,Department of Physical Chemistry IIRuhr University44780BochumGermany
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81
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Mitrea DM, Mittasch M, Gomes BF, Klein IA, Murcko MA. Modulating biomolecular condensates: a novel approach to drug discovery. Nat Rev Drug Discov 2022; 21:841-862. [PMID: 35974095 PMCID: PMC9380678 DOI: 10.1038/s41573-022-00505-4] [Citation(s) in RCA: 96] [Impact Index Per Article: 48.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/08/2022] [Indexed: 12/12/2022]
Abstract
In the past decade, membraneless assemblies known as biomolecular condensates have been reported to play key roles in many cellular functions by compartmentalizing specific proteins and nucleic acids in subcellular environments with distinct properties. Furthermore, growing evidence supports the view that biomolecular condensates often form by phase separation, in which a single-phase system demixes into a two-phase system consisting of a condensed phase and a dilute phase of particular biomolecules. Emerging understanding of condensate function in normal and aberrant cellular states, and of the mechanisms of condensate formation, is providing new insights into human disease and revealing novel therapeutic opportunities. In this Perspective, we propose that such insights could enable a previously unexplored drug discovery approach based on identifying condensate-modifying therapeutics (c-mods), and we discuss the strategies, techniques and challenges involved.
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82
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Mukherjee P, Panda P, Kasturi P. A comparative meta-analysis of membraneless organelle-associated proteins with age related proteome of C. elegans. Cell Stress Chaperones 2022; 27:619-631. [PMID: 36169889 PMCID: PMC9672229 DOI: 10.1007/s12192-022-01299-5] [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: 04/18/2022] [Revised: 09/09/2022] [Accepted: 09/13/2022] [Indexed: 01/25/2023] Open
Abstract
Proteome imbalance can lead to protein misfolding and aggregation which is associated with pathologies. Protein aggregation can also be an active, organized process and can be exploited by cells as a survival strategy. In adverse conditions, it is beneficial to deposit the proteins in a condensate rather degrading and resynthesizing. Membraneless organelles (MLOs) are biological condensates formed through liquid-liquid phase separation (LLPS), involving cellular components such as nucleic acids and proteins. LLPS is a regulated process, which when perturbed, can undergo a transition from a physiological liquid condensate to pathological solid-like protein aggregates. To understand how the MLO-associated proteins (MLO-APs) behave during aging, we performed a comparative meta-analysis with age-related proteome of C. elegans. We found that the MLO-APs are highly abundant throughout the lifespan in wild-type and long-lived daf-2 mutant animals. Interestingly, they are aggregating more in long-lived mutant animals compared to the age matched wild-type and short-lived daf-16 and hsf-1 mutant animals. GO term analysis revealed that the cell cycle and embryonic development are among the top enriched processes in addition to RNP components in aggregated proteome. Considering antagonistic pleotropic nature of these developmental genes and post mitotic status of C. elegans, we assume that these proteins phase transit during post development. As the organism ages, these MLO-APs either mature to become more insoluble or dissolve in uncontrolled manner. However, in the long-lived daf-2 mutant animals, the MLOs may attain protective states due to extended availability and association of molecular chaperones.
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Affiliation(s)
- Pritam Mukherjee
- BioX Centre, School of Biosciences and Bioengineering, Indian Institute of Technology Mandi, Kamand, Himachal Pradesh, 175005, India
| | - Prajnadipta Panda
- BioX Centre, School of Biosciences and Bioengineering, Indian Institute of Technology Mandi, Kamand, Himachal Pradesh, 175005, India
| | - Prasad Kasturi
- BioX Centre, School of Biosciences and Bioengineering, Indian Institute of Technology Mandi, Kamand, Himachal Pradesh, 175005, India.
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83
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Rapid Reversible Osmoregulation of Cytoplasmic Biomolecular Condensates of Human Interferon-α-Induced Antiviral MxA GTPase. Int J Mol Sci 2022; 23:ijms232112739. [PMID: 36361529 PMCID: PMC9655878 DOI: 10.3390/ijms232112739] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 10/18/2022] [Accepted: 10/20/2022] [Indexed: 01/24/2023] Open
Abstract
We previously discovered that exogenously expressed GFP-tagged cytoplasmic human myxovirus resistance protein (MxA), a major antiviral effector of Type I and III interferons (IFNs) against several RNA- and DNA-containing viruses, existed in the cytoplasm in phase-separated membraneless biomolecular condensates of varying sizes and shapes with osmotically regulated disassembly and reassembly. In this study we investigated whether cytoplasmic IFN-α-induced endogenous human MxA structures were also biomolecular condensates, displayed hypotonic osmoregulation and the mechanisms involved. Both IFN-α-induced endogenous MxA and exogenously expressed GFP-MxA formed cytoplasmic condensates in A549 lung and Huh7 hepatoma cells which rapidly disassembled within 1-2 min when cells were exposed to 1,6-hexanediol or to hypotonic buffer (~40-50 mOsm). Both reassembled into new structures within 1-2 min of shifting cells to isotonic culture medium (~330 mOsm). Strikingly, MxA condensates in cells continuously exposed to culture medium of moderate hypotonicity (in the range one-fourth, one-third or one-half isotonicity; range 90-175 mOsm) first rapidly disassembled within 1-3 min, and then, in most cells, spontaneously reassembled 7-15 min later into new structures. This spontaneous reassembly was inhibited by 2-deoxyglucose (thus, was ATP-dependent) and by dynasore (thus, required membrane internalization). Indeed, condensate reassembly was preceded by crowding of the cytosolic space by large vacuole-like dilations (VLDs) derived from internalized plasma membrane. Remarkably, the antiviral activity of GFP-MxA against vesicular stomatitis virus survived hypoosmolar disassembly and subsequent reassembly. The data highlight the exquisite osmosensitivity of MxA condensates, and the preservation of antiviral activity in the face of hypotonic stress.
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84
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Fefilova AS, Antifeeva IA, Gavrilova AA, Turoverov KK, Kuznetsova IM, Fonin AV. Reorganization of Cell Compartmentalization Induced by Stress. Biomolecules 2022; 12:1441. [PMID: 36291650 PMCID: PMC9599104 DOI: 10.3390/biom12101441] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Revised: 09/30/2022] [Accepted: 10/01/2022] [Indexed: 11/17/2022] Open
Abstract
The discovery of intrinsically disordered proteins (IDPs) that do not have an ordered structure and nevertheless perform essential functions has opened a new era in the understanding of cellular compartmentalization. It threw the bridge from the mostly mechanistic model of the organization of the living matter to the idea of highly dynamic and functional "soft matter". This paradigm is based on the notion of the major role of liquid-liquid phase separation (LLPS) of biopolymers in the spatial-temporal organization of intracellular space. The LLPS leads to the formation of self-assembled membrane-less organelles (MLOs). MLOs are multicomponent and multifunctional biological condensates, highly dynamic in structure and composition, that allow them to fine-tune the regulation of various intracellular processes. IDPs play a central role in the assembly and functioning of MLOs. The LLPS importance for the regulation of chemical reactions inside the cell is clearly illustrated by the reorganization of the intracellular space during stress response. As a reaction to various types of stresses, stress-induced MLOs appear in the cell, enabling the preservation of the genetic and protein material during unfavourable conditions. In addition, stress causes structural, functional, and compositional changes in the MLOs permanently present inside the cells. In this review, we describe the assembly of stress-induced MLOs and the stress-induced modification of existing MLOs in eukaryotes, yeasts, and prokaryotes in response to various stress factors.
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Affiliation(s)
| | | | | | - Konstantin K. Turoverov
- Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology of RAS, 194064 St. Petersburg, Russia
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85
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The Role of Small Heat Shock Proteins in Protein Misfolding Associated Motoneuron Diseases. Int J Mol Sci 2022; 23:ijms231911759. [PMID: 36233058 PMCID: PMC9569637 DOI: 10.3390/ijms231911759] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Revised: 09/29/2022] [Accepted: 09/30/2022] [Indexed: 11/17/2022] Open
Abstract
Motoneuron diseases (MNDs) are neurodegenerative conditions associated with death of upper and/or lower motoneurons (MNs). Proteostasis alteration is a pathogenic mechanism involved in many MNDs and is due to the excessive presence of misfolded and aggregated proteins. Protein misfolding may be the product of gene mutations, or due to defects in the translation process, or to stress agents; all these conditions may alter the native conformation of proteins making them prone to aggregate. Alternatively, mutations in members of the protein quality control (PQC) system may determine a loss of function of the proteostasis network. This causes an impairment in the capability to handle and remove aberrant or damaged proteins. The PQC system consists of the degradative pathways, which are the autophagy and the proteasome, and a network of chaperones and co-chaperones. Among these components, Heat Shock Protein 70 represents the main factor in substrate triage to folding, refolding, or degradation, and it is assisted in this task by a subclass of the chaperone network, the small heat shock protein (sHSPs/HSPBs) family. HSPBs take part in proteostasis by bridging misfolded and aggregated proteins to the HSP70 machinery and to the degradative pathways, facilitating refolding or clearance of the potentially toxic proteins. Because of its activity against proteostasis alteration, the chaperone system plays a relevant role in the protection against proteotoxicity in MNDs. Here, we discuss the role of HSPBs in MNDs and which HSPBs may represent a valid target for therapeutic purposes.
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86
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Bhattacharjee A, Ürmösi A, Jipa A, Kovács L, Deák P, Szabó Á, Juhász G. Loss of ubiquitinated protein autophagy is compensated by persistent cnc/NFE2L2/Nrf2 antioxidant responses. Autophagy 2022; 18:2385-2396. [PMID: 35184662 PMCID: PMC9543161 DOI: 10.1080/15548627.2022.2037852] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
SQSTM1/p62-type selective macroautophagy/autophagy receptors cross-link poly-ubiquitinated cargo and autophagosomal LC3/Atg8 proteins to deliver them for lysosomal degradation. Consequently, loss of autophagy leads to accumulation of polyubiquitinated protein aggregates that are also frequently seen in various human diseases, but their physiological relevance is incompletely understood. Here, using a genetically non-redundant Drosophila model, we show that specific disruption of ubiquitinated protein autophagy and concomitant formation of polyubiquitinated aggregates has hardly any effect on bulk autophagy, proteasome activity and fly healthspan. We find that accumulation of ref(2)P/SQSTM1 due to a mutation that disrupts its binding to Atg8a results in the co-sequestering of Keap1 and thus activates the cnc/NFE2L2/Nrf2 antioxidant pathway. These mutant flies have increased tolerance to oxidative stress and reduced levels of aging-associated mitochondrial superoxide. Interestingly, ubiquitin overexpression in ref(2)P point mutants prevents the formation of large aggregates and restores the cargo recognition ability of ref(2)P, although it does not prevent the activation of antioxidant responses. Taken together, potential detrimental effects of impaired ubiquitinated protein autophagy are compensated by the aggregation-induced antioxidant response.Abbreviations: Atg8a: Autophagy-related 8a; cnc: cap-n-collar; IFM: indirect flight muscle; KEAP1: kelch like ECH associated protein 1; LIR: LC3-interacting region; NFE2L2/Nrf2: NFE2 like bZIP transcription factor 2; PB1: Phox and Bem1; ref(2)P: refractory to sigma P; SAR: selective autophagy receptor; UBA: ubiquitin-associated.
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Affiliation(s)
| | - Adél Ürmösi
- Institute of Genetics; Biological Research Centre; Szeged, Hungary,Doctoral School of Biology; University of Szeged; Szeged, Hungary
| | - András Jipa
- Institute of Genetics; Biological Research Centre; Szeged, Hungary
| | - Levente Kovács
- Department of Genetics, University of Szeged, Szeged, Hungary,Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Péter Deák
- Department of Genetics, University of Szeged, Szeged, Hungary
| | - Áron Szabó
- Institute of Genetics; Biological Research Centre; Szeged, Hungary
| | - Gábor Juhász
- Institute of Genetics; Biological Research Centre; Szeged, Hungary,Department of Anatomy, Cell and Developmental Biology; Eötvös Loránd University; Budapest, Hungary,CONTACT Gábor Juhász Institute of Genetics; Biological Research Centre; Szeged, Hungary
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87
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Rizuan A, Jovic N, Phan TM, Kim YC, Mittal J. Developing Bonded Potentials for a Coarse-Grained Model of Intrinsically Disordered Proteins. J Chem Inf Model 2022; 62:4474-4485. [PMID: 36066390 PMCID: PMC10165611 DOI: 10.1021/acs.jcim.2c00450] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Recent advances in residue-level coarse-grained (CG) computational models have enabled molecular-level insights into biological condensates of intrinsically disordered proteins (IDPs), shedding light on the sequence determinants of their phase separation. The existing CG models that treat protein chains as flexible molecules connected via harmonic bonds cannot populate common secondary-structure elements. Here, we present a CG dihedral angle potential between four neighboring beads centered at Cα atoms to faithfully capture the transient helical structures of IDPs. In order to parameterize and validate our new model, we propose Cα-based helix assignment rules based on dihedral angles that succeed in reproducing the atomistic helicity results of a polyalanine peptide and folded proteins. We then introduce sequence-dependent dihedral angle potential parameters (εd) and use experimentally available helical propensities of naturally occurring 20 amino acids to find their optimal values. The single-chain helical propensities from the CG simulations for commonly studied prion-like IDPs are in excellent agreement with the NMR-based α-helix fraction, demonstrating that the new HPS-SS model can accurately produce structural features of IDPs. Furthermore, this model can be easily implemented for large-scale assembly simulations due to its simplicity.
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Affiliation(s)
- Azamat Rizuan
- Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, Texas 77843, United States
| | - Nina Jovic
- Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, Texas 77843, United States
| | - Tien M Phan
- Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, Texas 77843, United States
| | - Young C Kim
- Center for Materials Physics and Technology, Naval Research Laboratory, Washington, District of Columbia 20375, United States
| | - Jeetain Mittal
- Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, Texas 77843, United States
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88
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Wang A, Abulaiti X, Zhang H, Su H, Liu G, Gao S, Li L. Cancer Cells Evade Stress-Induced Apoptosis by Promoting HSP70-Dependent Clearance of Stress Granules. Cancers (Basel) 2022; 14:cancers14194671. [PMID: 36230594 PMCID: PMC9562925 DOI: 10.3390/cancers14194671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Revised: 09/21/2022] [Accepted: 09/22/2022] [Indexed: 11/16/2022] Open
Abstract
The formation of stress granules (SG) is regarded as a cellular mechanism to temporarily limit protein synthesis and prevent the unfolding of proteins in stressed cells. It has been noted that SG formation can promote the survival of stressed cells. Paradoxically, however, persistent SGs could cause cell death. The underlying molecular mechanism that affects the relationship between SG dynamics and cellular states is not fully understood. Here we found that SG dynamics in cancer cells differ significantly from those in normal cells. Specifically, prolonged stress caused the formation of persistent SGs and consequently resulted in apoptosis in the normal cells. By contrast, cancer cells resolved SGs and survived the prolonged stress. Regarding the mechanism, the knockdown of HSP70 or the inhibition of the HSP70s’ ATPase activity caused defective SG clearance, leading to apoptosis in otherwise healthy cancer cells. On the other hand, the knockout of G3BPs to block the formation of SGs allowed cancer cells to escape from the HSP70 inhibition-induced apoptosis. Given the observation that SG dynamics were barely affected by the inhibition of autophagy or proteasome, we propose that SG dynamics are regulated mainly by HSP70-mediated refolding of the unfolded proteins or their removal from SGs. As a result, cancer cells evade stress-induced apoptosis by promoting the HSP70-dependent SG clearance.
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Affiliation(s)
- Aifang Wang
- Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201210, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xianmixinuer Abulaiti
- Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201210, China
- Clinical and Translational Research Center of Shanghai First Maternity & Infant Hospital, Frontier Science Center for Stem Cells, School of Life Sciences and Technology, Tongji University, Shanghai 200092, China
| | - Han Zhang
- Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201210, China
| | - Hang Su
- Henan Key Laboratory of Stem Cell Differentiation and Modification, Henan Provincial People’s Hospital, Academy of Medical Science, Zhengzhou University, Zhengzhou 450053, China
| | - Guangzhi Liu
- Henan Key Laboratory of Stem Cell Differentiation and Modification, Henan Provincial People’s Hospital, Academy of Medical Science, Zhengzhou University, Zhengzhou 450053, China
| | - Shaorong Gao
- Clinical and Translational Research Center of Shanghai First Maternity & Infant Hospital, Frontier Science Center for Stem Cells, School of Life Sciences and Technology, Tongji University, Shanghai 200092, China
- Correspondence: (S.G.); (L.L.)
| | - Lingsong Li
- Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201210, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- Henan Key Laboratory of Stem Cell Differentiation and Modification, Henan Provincial People’s Hospital, Academy of Medical Science, Zhengzhou University, Zhengzhou 450053, China
- Correspondence: (S.G.); (L.L.)
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89
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Abstract
Condensed states of proteins, including liquid-like membraneless organelles and solid-like aggregates, contribute in fundamental ways to the organisation and function of the cell. Perturbations of these states can lead to a variety of diseases through mechanisms that we are now beginning to understand. We define protein condensation diseases as conditions caused by the disruption of the normal behaviour of the condensed states of proteins. We analyze the problem of the identification of targets for pharmacological interventions for these diseases and explore opportunities for the regulation of the formation and organisation of aberrant condensed states of proteins. In this review, the authors define protein condensation diseases as conditions caused by aberrant liquid-like or solid-like states of proteins, and describe opportunities for therapeutic interventions to restore the normal phase behaviour of proteins. The review accompanies the related collection of articles published in Nature Communications focusing on possible therapeutic approaches involving liquid-liquid phase separation.
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90
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Lacroix E, Audas TE. Keeping up with the condensates: The retention, gain, and loss of nuclear membrane-less organelles. Front Mol Biosci 2022; 9:998363. [PMID: 36203874 PMCID: PMC9530788 DOI: 10.3389/fmolb.2022.998363] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Accepted: 08/19/2022] [Indexed: 12/04/2022] Open
Abstract
In recent decades, a growing number of biomolecular condensates have been identified in eukaryotic cells. These structures form through phase separation and have been linked to a diverse array of cellular processes. While a checklist of established membrane-bound organelles is present across the eukaryotic domain, less is known about the conservation of membrane-less subcellular structures. Many of these structures can be seen throughout eukaryotes, while others are only thought to be present in metazoans or a limited subset of species. In particular, the nucleus is a hub of biomolecular condensates. Some of these subnuclear domains have been found in a broad range of organisms, which is a characteristic often attributed to essential functionality. However, this does not always appear to be the case. For example, the nucleolus is critical for ribosomal biogenesis and is present throughout the eukaryotic domain, while the Cajal bodies are believed to be similarly conserved, yet these structures are dispensable for organismal survival. Likewise, depletion of the Drosophila melanogaster omega speckles reduces viability, despite the apparent absence of this domain in higher eukaryotes. By reviewing primary research that has analyzed the presence of specific condensates (nucleoli, Cajal bodies, amyloid bodies, nucleolar aggresomes, nuclear speckles, nuclear paraspeckles, nuclear stress bodies, PML bodies, omega speckles, NUN bodies, mei2 dots) in a cross-section of organisms (e.g., human, mouse, D. melanogaster, Caenorhabditis elegans, yeast), we adopt a human-centric view to explore the emergence, retention, and absence of a subset of nuclear biomolecular condensates. This overview is particularly important as numerous biomolecular condensates have been linked to human disease, and their presence in additional species could unlock new and well characterized model systems for health research.
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Affiliation(s)
- Emma Lacroix
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada
- Centre for Cell Biology, Development, and Disease, Simon Fraser University, Burnaby, BC, Canada
| | - Timothy E. Audas
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada
- Centre for Cell Biology, Development, and Disease, Simon Fraser University, Burnaby, BC, Canada
- *Correspondence: Timothy E. Audas,
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91
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Rhine K, Al-Azzam N, Yu T, Yeo GW. Aging RNA granule dynamics in neurodegeneration. Front Mol Biosci 2022; 9:991641. [PMID: 36188213 PMCID: PMC9523239 DOI: 10.3389/fmolb.2022.991641] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Accepted: 08/22/2022] [Indexed: 12/30/2022] Open
Abstract
Disordered RNA-binding proteins and repetitive RNA sequences are the main genetic causes of several neurodegenerative diseases, including amyotrophic lateral sclerosis and Huntington's disease. Importantly, these components also seed the formation of cytoplasmic liquid-like granules, like stress granules and P bodies. Emerging evidence demonstrates that healthy granules formed via liquid-liquid phase separation can mature into solid- or gel-like inclusions that persist within the cell. These solidified inclusions are a precursor to the aggregates identified in patients, demonstrating that dysregulation of RNA granule biology is an important component of neurodegeneration. Here, we review recent literature highlighting how RNA molecules seed proteinaceous granules, the mechanisms of healthy turnover of RNA granules in cells, which biophysical properties underly a transition to solid- or gel-like material states, and why persistent granules disrupt the cellular homeostasis of neurons. We also identify various methods that will illuminate the contributions of disordered proteins and RNAs to neurodegeneration in ongoing research efforts.
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Affiliation(s)
- Kevin Rhine
- Department of Cellular and Molecular Medicine, University of California, San Diego, San Diego, CA, United States
- Stem Cell Program, University of California, San Diego, San Diego, CA, United States
- Institute for Genomic Medicine, University of California, San Diego, San Diego, CA, United States
| | - Norah Al-Azzam
- Department of Cellular and Molecular Medicine, University of California, San Diego, San Diego, CA, United States
- Stem Cell Program, University of California, San Diego, San Diego, CA, United States
- Institute for Genomic Medicine, University of California, San Diego, San Diego, CA, United States
- Neurosciences Graduate Program, University of California, San Diego, San Diego, CA, United States
| | - Tao Yu
- Department of Cellular and Molecular Medicine, University of California, San Diego, San Diego, CA, United States
- Stem Cell Program, University of California, San Diego, San Diego, CA, United States
- Institute for Genomic Medicine, University of California, San Diego, San Diego, CA, United States
| | - Gene W. Yeo
- Department of Cellular and Molecular Medicine, University of California, San Diego, San Diego, CA, United States
- Stem Cell Program, University of California, San Diego, San Diego, CA, United States
- Institute for Genomic Medicine, University of California, San Diego, San Diego, CA, United States
- Neurosciences Graduate Program, University of California, San Diego, San Diego, CA, United States
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92
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Proteostasis Deregulation in Neurodegeneration and Its Link with Stress Granules: Focus on the Scaffold and Ribosomal Protein RACK1. Cells 2022; 11:cells11162590. [PMID: 36010666 PMCID: PMC9406587 DOI: 10.3390/cells11162590] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 08/09/2022] [Accepted: 08/17/2022] [Indexed: 12/12/2022] Open
Abstract
The role of protein misfolding, deposition, and clearance has been the dominant topic in the last decades of investigation in the field of neurodegeneration. The impairment of protein synthesis, along with RNA metabolism and RNA granules, however, are significantly emerging as novel potential targets for the comprehension of the molecular events leading to neuronal deficits. Indeed, defects in ribosome activity, ribosome stalling, and PQC—all ribosome-related processes required for proteostasis regulation—can contribute to triggering stress conditions and promoting the formation of stress granules (SGs) that could evolve in the formation of pathological granules, usually occurring during neurodegenerating effects. In this review, the interplay between proteostasis, mRNA metabolism, and SGs has been explored in a neurodegenerative context with a focus on Alzheimer’s disease (AD), although some defects in these same mechanisms can also be found in frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS), which are discussed here. Finally, we highlight the role of the receptor for activated C kinase 1 (RACK1) in these pathologies and note that, besides its well characterized function as a scaffold protein, it has an important role in translation and can associate to stress granules (SGs) determining cell fate in response to diverse stress stimuli.
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93
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Li Z, Liu X, Liu M. Stress Granule Homeostasis, Aberrant Phase Transition, and Amyotrophic Lateral Sclerosis. ACS Chem Neurosci 2022; 13:2356-2370. [PMID: 35905138 DOI: 10.1021/acschemneuro.2c00262] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease. In recent years, a large number of ALS-related mutations have been discovered to have a strong link to stress granules (SGs). SGs are cytoplasmic ribonucleoprotein condensates mediated by liquid-liquid phase separation (LLPS) of biomacromolecules. They help cells cope with stress. The normal physiological functions of SGs are dependent on three key aspects of SG "homeostasis": SG assembly, disassembly, and SG components. Any of these three aspects can be disrupted, resulting in abnormalities in the cellular stress response and leading to cytotoxicity. Several ALS-related pathogenic mutants have abnormal LLPS abilities that disrupt SG homeostasis, and some of them can even cause aberrant phase transitions. As a result, ALS-related mutants may disrupt various aspects of SG homeostasis by directly disturbing the intermolecular interactions or affecting core SG components, thus disrupting the phase equilibrium of the cytoplasm during stress. Considering that the importance of the "global view" of SG homeostasis in ALS pathogenesis has not received enough attention, we first systematically summarize the physiological regulatory mechanism of SG homeostasis based on LLPS and then examine ALS pathogenesis from the perspective of disrupted SG homeostasis and aberrant phase transition of biomacromolecules.
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Affiliation(s)
- Zhanxu Li
- Xiangya School of Medicine, Central South University, Changsha 410078, Hunan, China
| | - Xionghao Liu
- Center for Medical Genetics & Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha 410008, Hunan, China
| | - Mujun Liu
- Department of Cell Biology, School of Life Sciences, Central South University, Changsha 410078, Hunan, China
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94
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Crosstalk between Biomolecular Condensates and Proteostasis. Cells 2022; 11:cells11152415. [PMID: 35954258 PMCID: PMC9368065 DOI: 10.3390/cells11152415] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Revised: 07/19/2022] [Accepted: 07/21/2022] [Indexed: 12/23/2022] Open
Abstract
Proper homeostasis of the proteome, referred to as proteostasis, is maintained by chaperone-dependent refolding of misfolded proteins and by protein degradation via the ubiquitin-proteasome system and the autophagic machinery. This review will discuss a crosstalk between biomolecular condensates and proteostasis, whereby the crowding of proteostasis factors into macromolecular assemblies is often established by phase separation of membraneless biomolecular condensates. Specifically, ubiquitin and other posttranslational modifications come into play as agents of phase separation, essential for the formation of condensates and for ubiquitin-proteasome system activity. Furthermore, an intriguing connection associates malfunction of the same pathways to the accumulation of misfolded and ubiquitinated proteins in aberrant condensates, the formation of protein aggregates, and finally, to the pathogenesis of neurodegenerative diseases. The crosstalk between biomolecular condensates and proteostasis is an emerging theme in cellular and disease biology and further studies will focus on delineating specific molecular pathways involved in the pathogenesis of amyotrophic lateral sclerosis (ALS) and other neurodegenerative diseases.
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95
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Lussier-Price M, Wahba HM, Mascle XH, Cappadocia L, Bourdeau V, Gagnon C, Igelmann S, Sakaguchi K, Ferbeyre G, Omichinski J. Zinc controls PML nuclear body formation through regulation of a paralog specific auto-inhibition in SUMO1. Nucleic Acids Res 2022; 50:8331-8348. [PMID: 35871297 PMCID: PMC9371903 DOI: 10.1093/nar/gkac620] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 06/22/2022] [Accepted: 07/06/2022] [Indexed: 12/24/2022] Open
Abstract
SUMO proteins are important regulators of many key cellular functions in part through their ability to form interactions with other proteins containing SUMO interacting motifs (SIMs). One characteristic feature of all SUMO proteins is the presence of a highly divergent intrinsically disordered region at their N-terminus. In this study, we examine the role of this N-terminal region of SUMO proteins in SUMO–SIM interactions required for the formation of nuclear bodies by the promyelocytic leukemia (PML) protein (PML-NBs). We demonstrate that the N-terminal region of SUMO1 functions in a paralog specific manner as an auto-inhibition domain by blocking its binding to the phosphorylated SIMs of PML and Daxx. Interestingly, we find that this auto-inhibition in SUMO1 is relieved by zinc, and structurally show that zinc stabilizes the complex between SUMO1 and a phospho-mimetic form of the SIM of PML. In addition, we demonstrate that increasing cellular zinc levels enhances PML-NB formation in senescent cells. Taken together, these results provide important insights into a paralog specific function of SUMO1, and suggest that zinc levels could play a crucial role in regulating SUMO1-SIM interactions required for PML-NB formation and function.
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Affiliation(s)
- Mathieu Lussier-Price
- Département de Biochimie et Médicine Moléculaire, Université de Montréal , Montréal, QC, Canada
| | - Haytham M Wahba
- Département de Biochimie et Médicine Moléculaire, Université de Montréal , Montréal, QC, Canada
- Department of Biochemistry, Beni-Suef University , Beni-Suef, Egypt
| | - Xavier H Mascle
- Département de Biochimie et Médicine Moléculaire, Université de Montréal , Montréal, QC, Canada
| | - Laurent Cappadocia
- Département de Biochimie et Médicine Moléculaire, Université de Montréal , Montréal, QC, Canada
| | - Veronique Bourdeau
- Département de Biochimie et Médicine Moléculaire, Université de Montréal , Montréal, QC, Canada
| | - Christina Gagnon
- Département de Biochimie et Médicine Moléculaire, Université de Montréal , Montréal, QC, Canada
| | - Sebastian Igelmann
- Département de Biochimie et Médicine Moléculaire, Université de Montréal , Montréal, QC, Canada
| | - Kazuyasu Sakaguchi
- Department of Chemistry, Faculty of Science, Hokkaido University , Sapporo, Japan
| | - Gerardo Ferbeyre
- Département de Biochimie et Médicine Moléculaire, Université de Montréal , Montréal, QC, Canada
| | - James G Omichinski
- Département de Biochimie et Médicine Moléculaire, Université de Montréal , Montréal, QC, Canada
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96
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Krokowski D, Jobava R, Szkop KJ, Chen CW, Fu X, Venus S, Guan BJ, Wu J, Gao Z, Banaszuk W, Tchorzewski M, Mu T, Ropelewski P, Merrick WC, Mao Y, Sevval AI, Miranda H, Qian SB, Manifava M, Ktistakis NT, Vourekas A, Jankowsky E, Topisirovic I, Larsson O, Hatzoglou M. Stress-induced perturbations in intracellular amino acids reprogram mRNA translation in osmoadaptation independently of the ISR. Cell Rep 2022; 40:111092. [PMID: 35858571 PMCID: PMC9491157 DOI: 10.1016/j.celrep.2022.111092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 04/26/2022] [Accepted: 06/22/2022] [Indexed: 12/23/2022] Open
Abstract
The integrated stress response (ISR) plays a pivotal role in adaptation of translation machinery to cellular stress. Here, we demonstrate an ISR-independent osmoadaptation mechanism involving reprogramming of translation via coordinated but independent actions of mTOR and plasma membrane amino acid transporter SNAT2. This biphasic response entails reduced global protein synthesis and mTOR signaling followed by translation of SNAT2. Induction of SNAT2 leads to accumulation of amino acids and reactivation of mTOR and global protein synthesis, paralleled by partial reversal of the early-phase, stress-induced translatome. We propose SNAT2 functions as a molecular switch between inhibition of protein synthesis and establishment of an osmoadaptive translation program involving the formation of cytoplasmic condensates of SNAT2-regulated RNA-binding proteins DDX3X and FUS. In summary, we define key roles of SNAT2 in osmotolerance.
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Affiliation(s)
- Dawid Krokowski
- Department of Genetics and Genome Sciences, School of Medicine, Case Western Reserve University, Cleveland, OH, USA; Department of Molecular Biology, Institute of Biological Sciences, Maria Curie-Skłodowska University, Lublin, Poland.
| | - Raul Jobava
- Department of Genetics and Genome Sciences, School of Medicine, Case Western Reserve University, Cleveland, OH, USA; Department of Biochemistry, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Krzysztof J Szkop
- Department of Oncology-Pathology, Science for Life Laboratories, Karolinska Institute, Stockholm, Sweden
| | - Chien-Wen Chen
- Department of Genetics and Genome Sciences, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Xu Fu
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Sarah Venus
- Department of Biochemistry, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Bo-Jhih Guan
- Department of Genetics and Genome Sciences, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Jing Wu
- Department of Genetics and Genome Sciences, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Zhaofeng Gao
- Department of Genetics and Genome Sciences, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Wioleta Banaszuk
- Department of Molecular Biology, Institute of Biological Sciences, Maria Curie-Skłodowska University, Lublin, Poland
| | - Marek Tchorzewski
- Department of Molecular Biology, Institute of Biological Sciences, Maria Curie-Skłodowska University, Lublin, Poland; EcoTech-Complex Centre, Maria Curie-Skłodowska University, Lublin, Poland
| | - Tingwei Mu
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Phil Ropelewski
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - William C Merrick
- Department of Biochemistry, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Yuanhui Mao
- Division of Nutritional Sciences, Cornell University, Ithaca, NY 14853, USA
| | - Aksoylu Inci Sevval
- Department of Oncology-Pathology, Science for Life Laboratories, Karolinska Institute, Stockholm, Sweden
| | - Helen Miranda
- Department of Genetics and Genome Sciences, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Shu-Bing Qian
- Division of Nutritional Sciences, Cornell University, Ithaca, NY 14853, USA
| | | | | | - Anastasios Vourekas
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803, USA
| | - Eckhard Jankowsky
- Department of Biochemistry, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Ivan Topisirovic
- The Lady Davis Institute, Jewish General Hospital, Montréal, QC, Canada; Gerald Bronfman Department of Oncology, McGill University, Montréal, QC, Canada; Department of Biochemistry and Division of Experimental Medicine, McGill University, Montréal, QC, Canada.
| | - Ola Larsson
- Department of Oncology-Pathology, Science for Life Laboratories, Karolinska Institute, Stockholm, Sweden.
| | - Maria Hatzoglou
- Department of Genetics and Genome Sciences, School of Medicine, Case Western Reserve University, Cleveland, OH, USA.
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97
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Liquid-liquid phase separation in tumor biology. Signal Transduct Target Ther 2022; 7:221. [PMID: 35803926 PMCID: PMC9270353 DOI: 10.1038/s41392-022-01076-x] [Citation(s) in RCA: 53] [Impact Index Per Article: 26.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 06/16/2022] [Accepted: 06/21/2022] [Indexed: 12/12/2022] Open
Abstract
Liquid–liquid phase separation (LLPS) is a novel principle for explaining the precise spatial and temporal regulation in living cells. LLPS compartmentalizes proteins and nucleic acids into micron-scale, liquid-like, membraneless bodies with specific functions, which were recently termed biomolecular condensates. Biomolecular condensates are executors underlying the intracellular spatiotemporal coordination of various biological activities, including chromatin organization, genomic stability, DNA damage response and repair, transcription, and signal transduction. Dysregulation of these cellular processes is a key event in the initiation and/or evolution of cancer, and emerging evidence has linked the formation and regulation of LLPS to malignant transformations in tumor biology. In this review, we comprehensively summarize the detailed mechanisms of biomolecular condensate formation and biophysical function and review the recent major advances toward elucidating the multiple mechanisms involved in cancer cell pathology driven by aberrant LLPS. In addition, we discuss the therapeutic perspectives of LLPS in cancer research and the most recently developed drug candidates targeting LLPS modulation that can be used to combat tumorigenesis.
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98
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Gosset P, Camu W, Raoul C, Mezghrani A. Prionoids in amyotrophic lateral sclerosis. Brain Commun 2022; 4:fcac145. [PMID: 35783556 PMCID: PMC9242622 DOI: 10.1093/braincomms/fcac145] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Revised: 03/16/2022] [Accepted: 06/01/2022] [Indexed: 12/20/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is the third most frequent neurodegenerative disease after Alzheimer’s and Parkinson’s disease. ALS is characterized by the selective and progressive loss of motoneurons in the spinal cord, brainstem and cerebral cortex. Clinical manifestations typically occur in midlife and start with focal muscle weakness, followed by the rapid and progressive wasting of muscles and subsequent paralysis. As with other neurodegenerative diseases, the condition typically begins at an initial point and then spreads along neuroanatomical tracts. This feature of disease progression suggests the spreading of prion-like proteins called prionoids in the affected tissues, which is similar to the spread of prion observed in Creutzfeldt-Jakob disease. Intensive research over the last decade has proposed the ALS-causing gene products Cu/Zn superoxide dismutase 1, TAR DNA-binding protein of 43 kDa, and fused in sarcoma as very plausible prionoids contributing to the spread of the pathology. In this review, we will discuss the molecular and cellular mechanisms leading to the propagation of these prionoids in ALS.
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Affiliation(s)
- Philippe Gosset
- INM, Univ Montpellier, INSERM, CNRS, Montpellier 34095, France
| | - William Camu
- INM, Univ Montpellier, INSERM, CNRS, Montpellier 34095, France
| | - Cedric Raoul
- INM, Univ Montpellier, INSERM, CNRS, Montpellier 34095, France
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99
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Jeon P, Ham HJ, Park S, Lee JA. Regulation of Cellular Ribonucleoprotein Granules: From Assembly to Degradation via Post-translational Modification. Cells 2022; 11:cells11132063. [PMID: 35805146 PMCID: PMC9265587 DOI: 10.3390/cells11132063] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Revised: 06/09/2022] [Accepted: 06/24/2022] [Indexed: 02/04/2023] Open
Abstract
Cells possess membraneless ribonucleoprotein (RNP) granules, including stress granules, processing bodies, Cajal bodies, or paraspeckles, that play physiological or pathological roles. RNP granules contain RNA and numerous RNA-binding proteins, transiently formed through the liquid–liquid phase separation. The assembly or disassembly of numerous RNP granules is strongly controlled to maintain their homeostasis and perform their cellular functions properly. Normal RNA granules are reversibly assembled, whereas abnormal RNP granules accumulate and associate with various neurodegenerative diseases. This review summarizes current studies on the physiological or pathological roles of post-translational modifications of various cellular RNP granules and discusses the therapeutic methods in curing diseases related to abnormal RNP granules by autophagy.
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100
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Li Y, Gu J, Wang C, Hu J, Zhang S, Liu C, Zhang S, Fang Y, Li D. Hsp70 exhibits a liquid-liquid phase separation ability and chaperones condensed FUS against amyloid aggregation. iScience 2022; 25:104356. [PMID: 35620440 PMCID: PMC9127583 DOI: 10.1016/j.isci.2022.104356] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 03/05/2022] [Accepted: 04/29/2022] [Indexed: 11/18/2022] Open
Abstract
Hsp70 is a key molecular chaperone in the protein quality control system to safeguard protein homeostasis in cells. Previous studies have shown that Hsp70 chaperones TDP-43, a pathogenic protein associated with amyotrophic lateral sclerosis (ALS), in nuclear bodies and prevents it from the pathological aggregation. In this work, we report that Hsp70 undergoes liquid-liquid phase separation, chaperones FUS, another ALS-linked pathogenic protein, in stress granules (SGs), and prevents condensed FUS from amyloid aggregation. Knock-down of Hsp70 does not influence SG assembly but results in the liquid-to-solid transition in SGs. NMR experiments further reveal Hsp70 predominantly uses its C-terminal substrate-binding domain to interact with the low complexity domain of FUS, which represents a mechanism distinct from that interacting with TDP-43. These findings suggest that Hsp70 is widely involved in chaperoning the physiological dynamics of various membrane-less organelles and adopts different mechanisms to prevent the pathological aggregation of different proteins.
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Affiliation(s)
- Yichen Li
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Ministry of Education, Shanghai Jiao Tong University, Shanghai 200030, China
- Zhangjiang Institute for Advanced Study, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Jinge Gu
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201210, China
- University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Chen Wang
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201210, China
- University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Jiaojiao Hu
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201210, China
- University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Shenqing Zhang
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Ministry of Education, Shanghai Jiao Tong University, Shanghai 200030, China
- Zhangjiang Institute for Advanced Study, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Cong Liu
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201210, China
| | - Shengnan Zhang
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201210, China
| | - Yanshan Fang
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201210, China
| | - Dan Li
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Ministry of Education, Shanghai Jiao Tong University, Shanghai 200030, China
- Zhangjiang Institute for Advanced Study, Shanghai Jiao Tong University, Shanghai 200240, China
- Bio-X-Renji Hospital Research Center, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200240, China
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