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Luan T, Li Q, Huang Z, Feng Y, Xu D, Zhou Y, Hu Y, Wang T. Axonopathy Underlying Amyotrophic Lateral Sclerosis: Unraveling Complex Pathways and Therapeutic Insights. Neurosci Bull 2024:10.1007/s12264-024-01267-2. [PMID: 39097850 DOI: 10.1007/s12264-024-01267-2] [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: 02/15/2024] [Accepted: 04/08/2024] [Indexed: 08/05/2024] Open
Abstract
Amyotrophic Lateral Sclerosis (ALS) is a complex neurodegenerative disorder characterized by progressive axonopathy, jointly leading to the dying back of the motor neuron, disrupting both nerve signaling and motor control. In this review, we highlight the roles of axonopathy in ALS progression, driven by the interplay of multiple factors including defective trafficking machinery, protein aggregation, and mitochondrial dysfunction. Dysfunctional intracellular transport, caused by disruptions in microtubules, molecular motors, and adaptors, has been identified as a key contributor to disease progression. Aberrant protein aggregation involving TDP-43, FUS, SOD1, and dipeptide repeat proteins further amplifies neuronal toxicity. Mitochondrial defects lead to ATP depletion, oxidative stress, and Ca2+ imbalance, which are regarded as key factors underlying the loss of neuromuscular junctions and axonopathy. Mitigating these defects through interventions including neurotrophic treatments offers therapeutic potential. Collaborative research efforts aim to unravel ALS complexities, opening avenues for holistic interventions that target diverse pathological mechanisms.
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Affiliation(s)
- Tongshu Luan
- The Brain Center, School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Qing Li
- The Brain Center, School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Zhi Huang
- The Brain Center, School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Yu Feng
- The Brain Center, School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Duo Xu
- The Brain Center, School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Yujie Zhou
- The Brain Center, School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Yiqing Hu
- The Brain Center, School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Tong Wang
- The Brain Center, School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China.
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2
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Read TA, Cisterna BA, Skruber K, Ahmadieh S, Liu TM, Vitriol JA, Shi Y, Black JB, Butler MT, Lindamood HL, Lefebvre AE, Cherezova A, Ilatovskaya DV, Bear JE, Weintraub NL, Vitriol EA. The actin binding protein profilin 1 localizes inside mitochondria and is critical for their function. EMBO Rep 2024; 25:3240-3262. [PMID: 39026010 PMCID: PMC11316047 DOI: 10.1038/s44319-024-00209-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Revised: 06/16/2024] [Accepted: 06/28/2024] [Indexed: 07/20/2024] Open
Abstract
The monomer-binding protein profilin 1 (PFN1) plays a crucial role in actin polymerization. However, mutations in PFN1 are also linked to hereditary amyotrophic lateral sclerosis, resulting in a broad range of cellular pathologies which cannot be explained by its primary function as a cytosolic actin assembly factor. This implies that there are important, undiscovered roles for PFN1 in cellular physiology. Here we screened knockout cells for novel phenotypes associated with PFN1 loss of function and discovered that mitophagy was significantly upregulated. Indeed, despite successful autophagosome formation, fusion with the lysosome, and activation of additional mitochondrial quality control pathways, PFN1 knockout cells accumulate depolarized, dysmorphic mitochondria with altered metabolic properties. Surprisingly, we also discovered that PFN1 is present inside mitochondria and provide evidence that mitochondrial defects associated with PFN1 loss are not caused by reduced actin polymerization in the cytosol. These findings suggest a previously unrecognized role for PFN1 in maintaining mitochondrial integrity and highlight new pathogenic mechanisms that can result from PFN1 dysregulation.
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Affiliation(s)
- Tracy-Ann Read
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia at Augusta University, Augusta, GA, USA.
| | - Bruno A Cisterna
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia at Augusta University, Augusta, GA, USA
| | - Kristen Skruber
- Department of Cellular and Molecular Pharmacology, University of California San Francisco, San Francisco, CA, USA
| | - Samah Ahmadieh
- Vascular Biology Center, Medical College of Georgia, Augusta University, Augusta, GA, USA
- Department of Medicine, Medical College of Georgia at Augusta University, Augusta, GA, USA
| | - Tatiana M Liu
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia at Augusta University, Augusta, GA, USA
| | - Josefine A Vitriol
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia at Augusta University, Augusta, GA, USA
| | - Yang Shi
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia at Augusta University, Augusta, GA, USA
- Department of Population Health Sciences, Medical College of Georgia at Augusta University, Augusta, GA, USA
| | - Joseph B Black
- Division of Urologic Surgery, Beth Israel Deaconess Medical Center, Boston, MA, USA
| | - Mitchell T Butler
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC, USA
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC, USA
| | - Halli L Lindamood
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia at Augusta University, Augusta, GA, USA
| | | | - Alena Cherezova
- Department of Physiology, Medical College of Georgia at Augusta University, Augusta, GA, USA
| | - Daria V Ilatovskaya
- Department of Physiology, Medical College of Georgia at Augusta University, Augusta, GA, USA
| | - James E Bear
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC, USA
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC, USA
| | - Neal L Weintraub
- Vascular Biology Center, Medical College of Georgia, Augusta University, Augusta, GA, USA
- Department of Medicine, Medical College of Georgia at Augusta University, Augusta, GA, USA
| | - Eric A Vitriol
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia at Augusta University, Augusta, GA, USA.
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3
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Lindamood HL, Liu TM, Read TA, Vitriol EA. Using ALS to understand profilin 1's diverse roles in cellular physiology. Cytoskeleton (Hoboken) 2024. [PMID: 39056295 DOI: 10.1002/cm.21896] [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: 04/23/2024] [Revised: 07/03/2024] [Accepted: 07/10/2024] [Indexed: 07/28/2024]
Abstract
Profilin is an actin monomer-binding protein whose role in actin polymerization has been studied for nearly 50 years. While its principal biochemical features are now well understood, many questions remain about how profilin controls diverse processes within the cell. Dysregulation of profilin has been implicated in a broad range of human diseases, including neurodegeneration, inflammatory disorders, cardiac disease, and cancer. For example, mutations in the profilin 1 gene (PFN1) can cause amyotrophic lateral sclerosis (ALS), although the precise mechanisms that drive neurodegeneration remain unclear. While initial work suggested proteostasis and actin cytoskeleton defects as the main pathological pathways, multiple novel functions for PFN1 have since been discovered that may also contribute to ALS, including the regulation of nucleocytoplasmic transport, stress granules, mitochondria, and microtubules. Here, we will review these newly discovered roles for PFN1, speculate on their contribution to ALS, and discuss how defects in actin can contribute to these processes. By understanding profilin 1's involvement in ALS pathogenesis, we hope to gain insight into this functionally complex protein with significant influence over cellular physiology.
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Affiliation(s)
- Halli L Lindamood
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia at Augusta University, Augusta, Georgia, USA
| | - Tatiana M Liu
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia at Augusta University, Augusta, Georgia, USA
| | - Tracy-Ann Read
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia at Augusta University, Augusta, Georgia, USA
| | - Eric A Vitriol
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia at Augusta University, Augusta, Georgia, USA
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4
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Mann N, Hill J, Wang K, Hughes RM. OptoProfilin: A Single Component Biosensor of Applied Cellular Stress. Chembiochem 2024; 25:e202400007. [PMID: 38457348 PMCID: PMC11218921 DOI: 10.1002/cbic.202400007] [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: 01/03/2024] [Revised: 03/08/2024] [Accepted: 03/08/2024] [Indexed: 03/10/2024]
Abstract
The actin cytoskeleton is a biosensor of cellular stress and a potential prognosticator of human disease. In particular, aberrant cytoskeletal structures such as stress granules formed in response to energetic and oxidative stress are closely linked to ageing, cancer, cardiovascular disease, and viral infection. Whether these cytoskeletal phenomena can be harnessed for the development of biosensors for cytoskeletal dysfunction and, by extension, disease progression, remains an open question. In this work, we describe the design and development of an optogenetic iteration of profilin, an actin monomer binding protein with critical functions in cytoskeletal dynamics. We demonstrate that this optically activated profilin ('OptoProfilin') can act as an optically triggered biosensor of applied cellular stress in select immortalized cell lines. Notably, OptoProfilin is a single component biosensor, likely increasing its utility for experimentalists. While a large body of preexisting work closely links profilin activity with cellular stress and neurodegenerative disease, this, to our knowledge, is the first example of profilin as an optogenetic biosensor of stress-induced changes in the cytoskeleton.
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Affiliation(s)
- Noah Mann
- Department of Chemistry, East Carolina University, Greenville, North Carolina, United States
| | - Jahiem Hill
- Department of Chemistry, East Carolina University, Greenville, North Carolina, United States
| | - Kenneth Wang
- Department of Chemistry, Davidson College, Davidson, North Carolina, United States
| | - Robert M Hughes
- Department of Chemistry, East Carolina University, Greenville, North Carolina, United States
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5
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Freibaum BD, Messing J, Nakamura H, Yurtsever U, Wu J, Kim HJ, Hixon J, Lemieux RM, Duffner J, Huynh W, Wong K, White M, Lee C, Meyers RE, Parker R, Taylor JP. Identification of small molecule inhibitors of G3BP-driven stress granule formation. J Cell Biol 2024; 223:e202308083. [PMID: 38284934 PMCID: PMC10824102 DOI: 10.1083/jcb.202308083] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Revised: 11/28/2023] [Accepted: 12/22/2023] [Indexed: 01/30/2024] Open
Abstract
Stress granule formation is triggered by the release of mRNAs from polysomes and is promoted by the action of the RNA-binding proteins G3BP1/2. Stress granules have been implicated in several disease states, including cancer and neurodegeneration. Consequently, compounds that limit stress granule formation or promote their dissolution have potential as both experimental tools and novel therapeutics. Herein, we describe two small molecules, G3BP inhibitor a and b (G3Ia and G3Ib), designed to bind to a specific pocket in G3BP1/2 that is targeted by viral inhibitors of G3BP1/2 function. In addition to disrupting the co-condensation of RNA, G3BP1, and caprin 1 in vitro, these compounds inhibit stress granule formation in cells treated prior to or concurrent with stress and dissolve pre-existing stress granules. These effects are consistent across multiple cell types and a variety of initiating stressors. Thus, these compounds represent powerful tools to probe the biology of stress granules and hold promise for therapeutic interventions designed to modulate stress granule formation.
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Affiliation(s)
- Brian D. Freibaum
- Department of Cell and Molecular Biology, St. Jude Children’s Research Hospital, Memphis, TN, USA
| | - James Messing
- Department of Cell and Molecular Biology, St. Jude Children’s Research Hospital, Memphis, TN, USA
| | - Haruko Nakamura
- Department of Cell and Molecular Biology, St. Jude Children’s Research Hospital, Memphis, TN, USA
| | - Ugur Yurtsever
- Department of Cell and Molecular Biology, St. Jude Children’s Research Hospital, Memphis, TN, USA
| | - Jinjun Wu
- Department of Cell and Molecular Biology, St. Jude Children’s Research Hospital, Memphis, TN, USA
| | - Hong Joo Kim
- Department of Cell and Molecular Biology, St. Jude Children’s Research Hospital, Memphis, TN, USA
| | | | | | | | | | | | | | | | | | - Roy Parker
- Department of Biochemistry, University of Colorado, Boulder, CO, USA
- Howard Hughes Medical Institute, Chevy Chase, MD, USA
| | - J. Paul Taylor
- Department of Cell and Molecular Biology, St. Jude Children’s Research Hospital, Memphis, TN, USA
- Howard Hughes Medical Institute, Chevy Chase, MD, USA
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6
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Zeng Y, Lovchykova A, Akiyama T, Liu C, Guo C, Jawahar VM, Sianto O, Calliari A, Prudencio M, Dickson DW, Petrucelli L, Gitler AD. TDP-43 nuclear loss in FTD/ALS causes widespread alternative polyadenylation changes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.22.575730. [PMID: 38328059 PMCID: PMC10849503 DOI: 10.1101/2024.01.22.575730] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2024]
Abstract
In frontotemporal dementia and amyotrophic lateral sclerosis, the RNA-binding protein TDP-43 is depleted from the nucleus. TDP-43 loss leads to cryptic exon inclusion but a role in other RNA processing events remains unresolved. Here, we show that loss of TDP-43 causes widespread changes in alternative polyadenylation, impacting expression of disease-relevant genes (e.g., ELP1, NEFL, and TMEM106B) and providing evidence that alternative polyadenylation is a new facet of TDP-43 pathology.
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Affiliation(s)
- Yi Zeng
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
| | | | - Tetsuya Akiyama
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
| | - Chang Liu
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
| | - Caiwei Guo
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
| | - Vidhya Maheswari Jawahar
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, USA
- Neuroscience Graduate Program, Mayo Clinic Graduate School of Biomedical Sciences, Jacksonville, FL, USA
| | - Odilia Sianto
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
| | - Anna Calliari
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, USA
- Neuroscience Graduate Program, Mayo Clinic Graduate School of Biomedical Sciences, Jacksonville, FL, USA
| | - Mercedes Prudencio
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, USA
- Neuroscience Graduate Program, Mayo Clinic Graduate School of Biomedical Sciences, Jacksonville, FL, USA
| | - Dennis W. Dickson
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, USA
- Neuroscience Graduate Program, Mayo Clinic Graduate School of Biomedical Sciences, Jacksonville, FL, USA
| | - Leonard Petrucelli
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, USA
- Neuroscience Graduate Program, Mayo Clinic Graduate School of Biomedical Sciences, Jacksonville, FL, USA
| | - Aaron D. Gitler
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
- Chan Zuckerberg Biohub – San Francisco, San Francisco, CA, USA
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7
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Wang F, Zhang Y. Physiology and pharmacological targeting of phase separation. J Biomed Sci 2024; 31:11. [PMID: 38245749 PMCID: PMC10800077 DOI: 10.1186/s12929-024-00993-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: 08/30/2023] [Accepted: 01/04/2024] [Indexed: 01/22/2024] Open
Abstract
Liquid-liquid phase separation (LLPS) in biology describes a process by which proteins form membraneless condensates within a cellular compartment when conditions are met, including the concentration and posttranslational modifications of the protein components, the condition of the aqueous solution (pH, ionic strength, pressure, and temperature), and the existence of assisting factors (such as RNAs or other proteins). In these supramolecular liquid droplet-like inclusion bodies, molecules are held together through weak intermolecular and/or intramolecular interactions. With the aid of LLPS, cells can assemble functional sub-units within a given cellular compartment by enriching or excluding specific factors, modulating cellular function, and rapidly responding to environmental or physiological cues. Hence, LLPS is emerging as an important means to regulate biology and physiology. Yet, excessive inclusion body formation by, for instance, higher-than-normal concentrations or mutant forms of the protein components could result in the conversion from dynamic liquid condensates into more rigid gel- or solid-like aggregates, leading to the disruption of the organelle's function followed by the development of human disorders like neurodegenerative diseases. In summary, well-controlled formation and de-formation of LLPS is critical for normal biology and physiology from single cells to individual organisms, whereas abnormal LLPS is involved in the pathophysiology of human diseases. In turn, targeting these aggregates or their formation represents a promising approach in treating diseases driven by abnormal LLPS including those neurodegenerative diseases that lack effective therapies.
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Affiliation(s)
- Fangfang Wang
- Department of Pharmacology, School of Medicine, Case Comprehensive Cancer Center, Case Western Reserve University, 2109 Adelbert Road, W309A, Cleveland, OH, 44106, USA
| | - Youwei Zhang
- Department of Pharmacology, School of Medicine, Case Comprehensive Cancer Center, Case Western Reserve University, 2109 Adelbert Road, W309A, Cleveland, OH, 44106, USA.
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8
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Mann N, Hill J, Wang K, Hughes RM. OptoProfilin: A Single Component Biosensor of Applied Cellular Stress. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.04.560945. [PMID: 37873064 PMCID: PMC10592976 DOI: 10.1101/2023.10.04.560945] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
The actin cytoskeleton is a biosensor of cellular stress and a potential prognosticator of human disease. In particular, aberrant cytoskeletal structures such as cofilin-actin rods and stress granules formed in response to energetic and oxidative stress are closely linked to neurodegenerative diseases such as Alzheimer's, Parkinson's, and ALS. Whether these cytoskeletal phenomena can be harnessed for the development of biosensors for cytoskeletal dysfunction and, by extension, neurodegenerative disease progression, remains an open question. In this work, we describe the design and development of an optogenetic iteration of profilin, an actin monomer binding protein with critical functions in cytoskeletal dynamics. We demonstrate that this optically activated profilin ('OptoProfilin') can act as an optically triggered biosensor of applied cellular stress in select immortalized cell lines. Notably, OptoProfilin is a single component biosensor, likely increasing its utility for experimentalists. While a large body of preexisting work closely links profilin activity with cellular stress and neurodegenerative disease, this, to our knowledge, is the first example of profilin as an optogenetic biosensor of stress-induced changes in the cytoskeleton.
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Affiliation(s)
- Noah Mann
- Department of Chemistry, East Carolina University, Greenville, North Carolina, United States
| | - Jahiem Hill
- Department of Chemistry, East Carolina University, Greenville, North Carolina, United States
| | - Kenneth Wang
- Department of Chemistry, Davidson College, Davidson, North Carolina, United States
| | - Robert M. Hughes
- Department of Chemistry, East Carolina University, Greenville, North Carolina, United States
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9
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Shimizu M, Shiraishi N, Tada S, Sasaki T, Beck G, Nagano S, Kinoshita M, Sumi H, Sugimoto T, Ishida Y, Koda T, Ishikura T, Sugiyama Y, Kihara K, Kanakura M, Nakajima T, Takeda S, Takahashi MP, Yamashita T, Okuno T, Mochizuki H. RGMa collapses the neuronal actin barrier against disease-implicated protein and exacerbates ALS. SCIENCE ADVANCES 2023; 9:eadg3193. [PMID: 37992159 PMCID: PMC10665002 DOI: 10.1126/sciadv.adg3193] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2022] [Accepted: 10/23/2023] [Indexed: 11/24/2023]
Abstract
Repulsive guidance molecule A (RGMa) was originally identified as a neuronal growth cone-collapsing factor. Previous reports have demonstrated the multifunctional roles of RGMa mediated by neogenin1. However, the pathogenic involvement of RGMa in amyotrophic lateral sclerosis (ALS) remains unclear. Here, we demonstrated that RGMa concentration was elevated in the cerebrospinal fluid of both patients with ALS and transgenic mice overexpressing the mutant human superoxide dismutase1 (mSOD1 mice). Treatment with humanized anti-RGMa monoclonal antibody ameliorated the clinical symptoms in mSOD1 mice. Histochemical analysis revealed that the anti-RGMa antibody significantly decreased mutant SOD1 protein accumulation in the motor neurons of mSOD1 mice via inhibition of actin depolymerization. In vitro analysis revealed that the anti-RGMa antibody inhibited the cellular uptake of the mutant SOD1 protein, presumably by reinforcing the neuronal actin barrier. Collectively, these data suggest that RGMa leads to the collapse of the neuronal actin barrier and promotes aberrant protein deposition, resulting in exacerbation of the ALS pathology.
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Affiliation(s)
- Mikito Shimizu
- Department of Neurology, Neuroscience, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - Naoyuki Shiraishi
- Department of Neurology, Neuroscience, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - Satoru Tada
- Department of Neurology, Neuroscience, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
- Department of Clinical Research, National Hospital Organization Osaka-Minami Medical Center, Kawachinagano, Osaka, Japan
| | - Tsutomu Sasaki
- Department of Neurology, Neuroscience, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - Goichi Beck
- Department of Neurology, Neuroscience, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - Seiichi Nagano
- Department of Neurology, Neuroscience, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
- Department of Neurotherapeutics, Neuroscience, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - Makoto Kinoshita
- Department of Neurology, Neuroscience, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - Hisae Sumi
- Department of Neurology, Neuroscience, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
- Department of Neurology, Higashiosaka City Medical Center, Higashiosaka, Osaka, Japan
| | - Tomoyuki Sugimoto
- Graduate School of Data Science, Shiga University, Hikone, Shiga, Japan
| | - Yoko Ishida
- Department of Neurology, Neuroscience, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - Toru Koda
- Department of Neurology, Neuroscience, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - Teruyuki Ishikura
- Department of Neurology, Neuroscience, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
- Department of Neurology, Higashiosaka City Medical Center, Higashiosaka, Osaka, Japan
| | - Yasuko Sugiyama
- Department of Neurology, Neuroscience, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - Keigo Kihara
- Department of Neurology, Neuroscience, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - Minami Kanakura
- Department of Neurology, Neuroscience, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
- Department of Health Sciences, Neuroscience, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - Tsuneo Nakajima
- Department of Geriatric and General Medicine, Neuroscience, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - Shuko Takeda
- Department of Clinical Gene Therapy, Neuroscience, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
- Osaka Psychiatric Research Center, Osaka Psychiatric Medical Center, Hirakata, Osaka, Japan
| | - Masanori P. Takahashi
- Department of Neurology, Neuroscience, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
- Department of Health Sciences, Neuroscience, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - Toshihide Yamashita
- Department of Molecular Neuroscience, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - Tatsusada Okuno
- Department of Neurology, Neuroscience, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - Hideki Mochizuki
- Department of Neurology, Neuroscience, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
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10
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Sheehan CJ, Marayati BF, Bhatia J, Meyer K. In situ visualization of m6A sites in cellular mRNAs. Nucleic Acids Res 2023; 51:e101. [PMID: 37811887 PMCID: PMC10639046 DOI: 10.1093/nar/gkad787] [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: 06/20/2023] [Revised: 09/12/2023] [Accepted: 09/15/2023] [Indexed: 10/10/2023] Open
Abstract
N 6-methyladenosine (m6A) is an abundant RNA modification which plays critical roles in RNA function and cellular physiology. However, our understanding of how m6A is spatially regulated remains limited due to a lack of methods for visualizing methylated transcripts of interest in cells. Here, we develop DART-FISH, a method for in situ visualization of specific m6A sites in target RNAs which enables simultaneous detection of both m6A-modified and unmodified transcript copies. We demonstrate the ability of DART-FISH to visualize m6A in a variety of mRNAs across diverse cell types and to provide information on the location and stoichiometry of m6A sites at single-cell resolution. Finally, we use DART-FISH to reveal that m6A is not sufficient for mRNA localization to stress granules during oxidative stress. This technique provides a powerful tool for examining m6A-modified transcript dynamics and investigating methylated RNA localization in individual cells.
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Affiliation(s)
- Charles J Sheehan
- Department of Biochemistry, Duke University School of Medicine, Durham, NC, USA
| | | | - Janvi Bhatia
- Trinity College of Arts and Sciences, Duke University, Durham, NC, USA
| | - Kate D Meyer
- Department of Biochemistry, Duke University School of Medicine, Durham, NC, USA
- Department of Neurobiology, Duke University School of Medicine, Durham, NC, USA
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11
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Wei S, Yang Y, Wang Y. Proximity Proteomics Revealed Aberrant mRNA Splicing Elicited by ALS-Linked Profilin-1 Mutants. Anal Chem 2023; 95:15141-15145. [PMID: 37787459 PMCID: PMC10689300 DOI: 10.1021/acs.analchem.3c03734] [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] [Indexed: 10/04/2023]
Abstract
Profilin 1 (PFN1) is a cytoskeleton protein that modulates actin dynamics through binding to monomeric actin and polyproline-containing proteins. Mutations in PFN1 have been linked to the pathogenesis of familial amyotrophic lateral sclerosis (ALS). Here, we employed an unbiased proximity labeling strategy in combination with proteomic analysis for proteome-wide profiling of proteins that differentially interact with mutant and wild-type (WT) PFN1 proteins in human cells. We uncovered 11 mRNA splicing proteins that are preferentially enriched in the proximity proteomes of the two ALS-linked PFN1 variants, C71G and M114T, over that of wild-type PFN1. We validated the preferential interactions of the ALS-linked PFN1 variants with two mRNA splicing factors, hnRNPC and U2AF2, by immunoprecipitation, followed with immunoblotting. We also found that the two ALS-linked PFN1 variants promoted the exonization of Alu elements in the mRNAs of MTO1, TCFL5, WRN and POLE genes in human cells. Together, we showed that the two ALS-linked PFN1 variants interacted preferentially with mRNA splicing proteins, which elicited aberrant exonization of the Alu elements in mRNAs. Thus, our work provided pivotal insights into the perturbations of ALS-linked PFN1 variants in RNA biology and their potential contributions to ALS pathology.
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Affiliation(s)
- Songbo Wei
- Department of Chemistry, University of California, Riverside, California 92521-0403, United States
| | - YenYu Yang
- Department of Chemistry, University of California, Riverside, California 92521-0403, United States
| | - Yinsheng Wang
- Department of Chemistry, University of California, Riverside, California 92521-0403, United States
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12
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Gitau JK, Macharia RW, Mwangi KW, Ongeso N, Murungi E. Gene co-expression network identifies critical genes, pathways and regulatory motifs mediating the progression of rift valley fever in Bostaurus. Heliyon 2023; 9:e18175. [PMID: 37519716 PMCID: PMC10375796 DOI: 10.1016/j.heliyon.2023.e18175] [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: 08/01/2022] [Revised: 07/04/2023] [Accepted: 07/10/2023] [Indexed: 08/01/2023] Open
Abstract
Rift Valley Fever (RVF) is a mosquito-borne viral disease caused by the Rift Valley Fever Virus. The disease is a zoonosis that largely affects domestic animals, including sheep, goats, and cattle, resulting in severe morbidity and mortality marked by massive storm abortions. To halt human and livestock deaths due to RVF, the development of efficacious vaccines and therapeutics is a compelling and urgent priority. We sought to identify potential key modules (gene clusters), hub genes, and regulatory motifs involved in the pathogenesis of RVF in Bos taurus that are amenable to inhibition. We analyzed 39 Bos taurus RNA-Seq samples using the weighted gene co-expression network analysis (WGCNA) R package and uncovered significantly enriched modules containing genes with potential pivotal roles in RVF progression. Moreover, regulatory motif analysis conducted using the Multiple Expectation Maximization for Motif Elicitation (MEME) suite identified motifs that probably modulate vital biological processes. Gene ontology terms associated with identified motifs were inferred using the GoMo human database. The gene co-expression network constructed in WGCNA using 5000 genes contained seven (7) modules, out of which four were significantly enriched for terms associated with response to viruses, response to interferon-alpha, innate immune response, and viral defense. Additionally, several biological pathways implicated in developmental processes, anatomical structure development, and multicellular organism development were identified. Regulatory motifs analysis identified short, repeated motifs whose function(s) may be amenable to disruption by novel therapeutics. Predicted functions of identified motifs include tissue development, embryonic organ development, and organ morphogenesis. We have identified several hub genes in enriched co-expressed gene modules and regulatory motifs potentially involved in the pathogenesis of RVF in B. taurus that are likely viable targets for disruption by novel therapeutics.
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Affiliation(s)
- John K. Gitau
- University of Nairobi, Biochemistry Department, P.O Box 30197, 00100, Nairobi, Kenya
| | - Rosaline W. Macharia
- University of Nairobi, Biochemistry Department, P.O Box 30197, 00100, Nairobi, Kenya
| | - Kennedy W. Mwangi
- Jomo Kenyatta University of Agriculture and Technology, P.O Box 62000, 00200, Nairobi, Kenya
| | - Nehemiah Ongeso
- University of Nairobi, Biochemistry Department, P.O Box 30197, 00100, Nairobi, Kenya
| | - Edwin Murungi
- Kisii University, Department of Medical Biochemistry, P.O Box 408, 40200, Kisii, Kenya
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13
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Freibaum BD, Messing J, Nakamura H, Yurtsever U, Wu J, Kim HJ, Hixon J, Lemieux R, Duffner J, Huynh W, Wong K, White M, Lee C, Meyers R, Parker R, Taylor JP. Identification of small molecule inhibitors of G3BP-driven stress granule formation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.27.546770. [PMID: 37425931 PMCID: PMC10327151 DOI: 10.1101/2023.06.27.546770] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/11/2023]
Abstract
Stress granule formation is triggered by the release of mRNAs from polysomes and is promoted by the action of the paralogs G3BP1 and G3BP2. G3BP1/2 proteins bind mRNAs and thereby promote the condensation of mRNPs into stress granules. Stress granules have been implicated in several disease states, including cancer and neurodegeneration. Consequently, compounds that limit stress granule formation or promote their dissolution have potential as both experimental tools and novel therapeutics. Herein, we describe two small molecules, referred to as G3BP inhibitor a and b (G3Ia and G3Ib), designed to bind to a specific pocket in G3BP1/2 that is known to be targeted by viral inhibitors of G3BP1/2 function. In addition to disrupting co-condensation of RNA, G3BP1, and caprin 1 in vitro, these compounds inhibit stress granule formation in cells treated prior to or concurrent with stress, and dissolve pre-existing stress granules when added to cells after stress granule formation. These effects are consistent across multiple cell types and a variety of initiating stressors. Thus, these compounds represent ideal tools to probe the biology of stress granules and hold promise for therapeutic interventions designed to modulate stress granule formation.
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Affiliation(s)
- Brian D Freibaum
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - James Messing
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Haruko Nakamura
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Ugur Yurtsever
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Jinjun Wu
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Hong Joo Kim
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Jeff Hixon
- Faze Medicines, Cambridge, Massachusetts, USA
| | | | - Jay Duffner
- Faze Medicines, Cambridge, Massachusetts, USA
| | | | - Kathy Wong
- Faze Medicines, Cambridge, Massachusetts, USA
| | | | | | | | - Roy Parker
- Department of Biochemistry, Howard Hughes Medical Institute, University of Colorado, Boulder, Colorado, USA
| | - J Paul Taylor
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, Tennessee, USA
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14
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Huang Y, Zhou B. Mitochondrial Dysfunction in Cardiac Diseases and Therapeutic Strategies. Biomedicines 2023; 11:biomedicines11051500. [PMID: 37239170 DOI: 10.3390/biomedicines11051500] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Revised: 05/15/2023] [Accepted: 05/16/2023] [Indexed: 05/28/2023] Open
Abstract
Mitochondria are the main site of intracellular synthesis of ATP, which provides energy for various physiological activities of the cell. Cardiomyocytes have a high density of mitochondria and mitochondrial damage is present in a variety of cardiovascular diseases. In this paper, we describe mitochondrial damage in mitochondrial cardiomyopathy, congenital heart disease, coronary heart disease, myocardial ischemia-reperfusion injury, heart failure, and drug-induced cardiotoxicity, in the context of the key roles of mitochondria in cardiac development and homeostasis. Finally, we discuss the main current therapeutic strategies aimed at alleviating mitochondrial impairment-related cardiac dysfunction, including pharmacological strategies, gene therapy, mitochondrial replacement therapy, and mitochondrial transplantation. It is hoped that this will provide new ideas for the treatment of cardiovascular diseases.
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Affiliation(s)
- Yafei Huang
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Science and Peking Union Medical College, 167 North Lishi Road, Xicheng District, Beijing 100037, China
| | - Bingying Zhou
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Science and Peking Union Medical College, 167 North Lishi Road, Xicheng District, Beijing 100037, China
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15
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Sahana TG, Chase KJ, Liu F, Lloyd TE, Rossoll W, Zhang K. c-Jun N-Terminal Kinase Promotes Stress Granule Assembly and Neurodegeneration in C9orf72-Mediated ALS and FTD. J Neurosci 2023; 43:3186-3197. [PMID: 37015810 PMCID: PMC10146492 DOI: 10.1523/jneurosci.1799-22.2023] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 02/09/2023] [Accepted: 03/15/2023] [Indexed: 04/06/2023] Open
Abstract
Stress granules are the RNA/protein condensates assembled in the cells under stress. They play a critical role in the pathogenesis of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). However, how stress granule assembly is regulated and related to ALS/FTD pathomechanism is incompletely understood. Mutation in the C9orf72 gene is the most common cause of familial ALS and FTD. C9orf72 mutation causes the formation of toxic dipeptide repeats. Here we show that the two most toxic dipeptide repeats [i.e., poly(GR) and poly(PR)] activate c-Jun N-terminal kinase (JNK) via the ER-stress response protein IRE1 using fly and cellular models. Further, we show that activated JNK promotes stress granule assembly in cells by promoting the transcription of one of the key stress granule proteins (i.e., G3BP1) by inducing histone 3 phosphorylation. Consistent with these findings, JNK or IRE1 inhibition reduced stress granule formation, histone 3 phosphorylation, G3BP1 mRNA and protein levels, and neurotoxicity in cells overexpressing poly(GR) and poly(PR) or neurons derived from male and female C9ALS/FTD patient-induced pluripotent stem cells. Our findings connect ER stress, JNK activation, and stress granule assembly in a unified pathway contributing to C9ALS/FTD neurodegeneration.SIGNIFICANCE STATEMENT c-Jun N-terminal kinase (JNK) is a part of the mitogen-activated protein kinase pathway, which is the central node for the integration of multiple stress signals. Cells are under constant stress in neurodegenerative diseases, and how these cells respond to stress signals is a critical factor in determining their survival or death. Previous studies have shown JNK as a major contributor to cellular apoptosis. Here, we show the role of JNK in stress granule assembly. We identify that toxic dipeptide repeats produced in ALS/FTD conditions activate JNK. The activated JNK in the nucleus can induce histone modifications which increase G3BP1 expression, thus promoting stress granule assembly and neurodegeneration.
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Affiliation(s)
| | | | - Feilin Liu
- Department of Neuroscience, Mayo Clinic, Jacksonville, Florida 32224
| | - Thomas E Lloyd
- Department of Neurology, Johns Hopkins School of Medicine, Baltimore, Maryland 21205
| | - Wilfried Rossoll
- Department of Neuroscience, Mayo Clinic, Jacksonville, Florida 32224
- Neuroscience Graduate Program, Mayo Clinic Graduate School of Biomedical Sciences, Jacksonville, Florida 32224
| | - Ke Zhang
- Department of Neuroscience, Mayo Clinic, Jacksonville, Florida 32224
- Neuroscience Graduate Program, Mayo Clinic Graduate School of Biomedical Sciences, Jacksonville, Florida 32224
- Institute of Neurological and Psychiatric Disorders, Shenzhen Bay Laboratory, Gaoke Innovation Centre A16, Guangqiao Rd, Shenzhen, Guangdong 518107, China, P.R
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16
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Fujikawa D, Nakamura T, Yoshioka D, Li Z, Moriizumi H, Taguchi M, Tokai-Nishizumi N, Kozuka-Hata H, Oyama M, Takekawa M. Stress granule formation inhibits stress-induced apoptosis by selectively sequestering executioner caspases. Curr Biol 2023; 33:1967-1981.e8. [PMID: 37119817 DOI: 10.1016/j.cub.2023.04.012] [Citation(s) in RCA: 17] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 02/23/2023] [Accepted: 04/06/2023] [Indexed: 05/01/2023]
Abstract
Cytoplasmic stress granules (SGs) are phase-separated membrane-less organelles that form in response to various stress stimuli. SGs are mainly composed of non-canonical stalled 48S preinitiation complexes. In addition, many other proteins also accumulate into SGs, but the list is still incomplete. SG assembly suppresses apoptosis and promotes cell survival under stress. Furthermore, hyperformation of SGs is frequently observed in various human cancers and accelerates tumor development and progression by reducing stress-induced damage of cancer cells. Therefore, they are of clinical importance. However, the precise mechanism underlying SG-mediated inhibition of apoptosis remains ill-defined. Here, using a proximity-labeling proteomic approach, we comprehensively analyzed SG-resident proteins and identified the executioner caspases, caspase-3 and -7, as SG components. We demonstrate that accumulation of caspase-3/7 into SGs is mediated by evolutionarily conserved amino acid residues within their large catalytic domains and inhibits caspase activities and consequent apoptosis induced by various stresses. Expression of an SG-localization-deficient caspase-3 mutant in cells largely counteracted the anti-apoptotic effect of SGs, whereas enforced relocalization of the caspase-3 mutant to SGs restored it. Thus, SG-mediated sequestration of executioner caspases is a mechanism underlying the broad cytoprotective function of SGs. Furthermore, using a mouse xenograft tumor model, we show that this mechanism prevents cancer cells from apoptosis in tumor tissues, thereby promoting cancer progression. Our results reveal the functional crosstalk between SG-mediated cell survival and caspase-mediated cell death signaling pathways and delineate a molecular mechanism that dictates cell-fate decisions under stress and promotes tumorigenesis.
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Affiliation(s)
- Daichi Fujikawa
- Division of Cell Signaling and Molecular Medicine, Institute of Medical Science, The University of Tokyo, 4-6-1, Shirokanedai, Minato-ku, Tokyo 108-8639, Japan; Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Takanori Nakamura
- Division of Cell Signaling and Molecular Medicine, Institute of Medical Science, The University of Tokyo, 4-6-1, Shirokanedai, Minato-ku, Tokyo 108-8639, Japan
| | - Daisuke Yoshioka
- Division of Cell Signaling and Molecular Medicine, Institute of Medical Science, The University of Tokyo, 4-6-1, Shirokanedai, Minato-ku, Tokyo 108-8639, Japan; Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5, Kashiwanoha, Kashiwa 277-8562, Chiba, Japan
| | - Zizheng Li
- Division of Cell Signaling and Molecular Medicine, Institute of Medical Science, The University of Tokyo, 4-6-1, Shirokanedai, Minato-ku, Tokyo 108-8639, Japan; Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5, Kashiwanoha, Kashiwa 277-8562, Chiba, Japan
| | - Hisashi Moriizumi
- Division of Cell Signaling and Molecular Medicine, Institute of Medical Science, The University of Tokyo, 4-6-1, Shirokanedai, Minato-ku, Tokyo 108-8639, Japan; Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5, Kashiwanoha, Kashiwa 277-8562, Chiba, Japan
| | - Mari Taguchi
- Division of Cell Signaling and Molecular Medicine, Institute of Medical Science, The University of Tokyo, 4-6-1, Shirokanedai, Minato-ku, Tokyo 108-8639, Japan; Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Noriko Tokai-Nishizumi
- Division of Cell Signaling and Molecular Medicine, Institute of Medical Science, The University of Tokyo, 4-6-1, Shirokanedai, Minato-ku, Tokyo 108-8639, Japan
| | - Hiroko Kozuka-Hata
- Medical Proteomics Laboratory, Institute of Medical Science, The University of Tokyo, 4-6-1, Shirokanedai, Minato-ku, Tokyo 108-8639, Japan
| | - Masaaki Oyama
- Medical Proteomics Laboratory, Institute of Medical Science, The University of Tokyo, 4-6-1, Shirokanedai, Minato-ku, Tokyo 108-8639, Japan
| | - Mutsuhiro Takekawa
- Division of Cell Signaling and Molecular Medicine, Institute of Medical Science, The University of Tokyo, 4-6-1, Shirokanedai, Minato-ku, Tokyo 108-8639, Japan; Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan; Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5, Kashiwanoha, Kashiwa 277-8562, Chiba, Japan; Medical Proteomics Laboratory, Institute of Medical Science, The University of Tokyo, 4-6-1, Shirokanedai, Minato-ku, Tokyo 108-8639, Japan.
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17
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Muneeswaran G, Lee JY. Mechanistic insights into the conformational switch in profilin-1 subject to collective effects of mutation and histidine tautomerism. Int J Biol Macromol 2023; 230:123403. [PMID: 36706877 DOI: 10.1016/j.ijbiomac.2023.123403] [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: 11/13/2022] [Revised: 01/16/2023] [Accepted: 01/19/2023] [Indexed: 01/26/2023]
Abstract
Mutations and histidine (His) tautomerism in profilin-1 (PFN1) are associated with amyotrophic lateral sclerosis (ALS). The conformational changes in PFN1 caused by the collective effects of G117V mutation and His tautomeric isomers εε, εδ, δε, and δδ were clarified using molecular dynamics (MD) simulations. The predominant structural variations were seen in α-helices, β-sheets, turns, and coils and the His tautomer's unique degree of disruption was seen in these conformations. The content of α-helices was 23.2 % in the εε and δδ isomers, but the observed α-helices in the isomers εδ and δε were 20.3 % and 21.7 % respectively. The percentage of β-sheet was found to be higher (34.1) in the εε isomer than in the εδ, δε, and δδ isomers, and the values were 30.4, 29.7, and 31.9, respectively. Intermolecular water dynamics analysis discloses that His 133 can form an intramolecular H-bond interaction (Nα-H---Nδ), confirming the experimental observations in the simulations of εε, δε, and δδ isomers of G117V PFN1 mutant. It was concluded that these solvent molecules are crucial for aggregation and must be considered in future research on the PFN1 associated with ALS. Overall, the study offers a thorough microscopic understanding of the pathogenic mechanisms behind conformational changes that cause aggregation illnesses like ALS.
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Affiliation(s)
- Gurusamy Muneeswaran
- Department of Chemistry, Sungkyunkwan University, Suwon 16419, Republic of Korea; Department of Physics and Astronomy, Clemson University, Clemson, SC 29634, USA
| | - Jin Yong Lee
- Department of Chemistry, Sungkyunkwan University, Suwon 16419, Republic of Korea.
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18
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Actin dynamics in protein homeostasis. Biosci Rep 2022; 42:231720. [PMID: 36043949 PMCID: PMC9469105 DOI: 10.1042/bsr20210848] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 08/22/2022] [Accepted: 08/31/2022] [Indexed: 11/17/2022] Open
Abstract
Cell homeostasis is maintained in all organisms by the constant adjustment of cell constituents and organisation to account for environmental context. Fine-tuning of the optimal balance of proteins for the conditions, or protein homeostasis, is critical to maintaining cell homeostasis. Actin, a major constituent of the cytoskeleton, forms many different structures which are acutely sensitive to the cell environment. Furthermore, actin structures interact with and are critically important for the function and regulation of multiple factors involved with mRNA and protein production and degradation, and protein regulation. Altogether, actin is a key, if often overlooked, regulator of protein homeostasis across eukaryotes. In this review, we highlight these roles and how they are altered following cell stress, from mRNA transcription to protein degradation.
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19
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Multiple roles for the cytoskeleton in ALS. Exp Neurol 2022; 355:114143. [PMID: 35714755 PMCID: PMC10163623 DOI: 10.1016/j.expneurol.2022.114143] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Revised: 06/05/2022] [Accepted: 06/08/2022] [Indexed: 11/20/2022]
Abstract
Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease caused by more than sixty genes identified through classic linkage analysis and new sequencing methods. Yet no clear mechanism of onset, cure, or effective treatment is known. Popular discourse classifies the proteins encoded from ALS-related genes into four disrupted processes: proteostasis, mitochondrial function and ROS, nucleic acid regulation, and cytoskeletal dynamics. Surprisingly, the mechanisms detailing the contribution of the neuronal cytoskeletal in ALS are the least explored, despite involvement in these cell processes. Eight genes directly regulate properties of cytoskeleton function and are essential for the health and survival of motor neurons, including: TUBA4A, SPAST, KIF5A, DCTN1, NF, PRPH, ALS2, and PFN1. Here we review the properties and studies exploring the contribution of each of these genes to ALS.
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20
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Muneeswaran G, Lee JY. Histidine tautomerism dependent conformational transitions driven aggregation of profilin-1: Implications in amyotrophic lateral sclerosis. Int J Biol Macromol 2022; 214:241-251. [PMID: 35688275 DOI: 10.1016/j.ijbiomac.2022.06.007] [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] [Received: 04/04/2022] [Revised: 05/17/2022] [Accepted: 06/01/2022] [Indexed: 11/26/2022]
Abstract
Aggregation of profilin-1 (PFN1) causes a fatal neurodegenerative disease, familial amyotrophic lateral sclerosis (fALS). Histidine (His) tautomerism has been linked to the formation of fibril aggregation causing neurodegenerative disease. Characterization of intermediate species that form during aggregation is crucial, however, this has proven very challenging for experimentalists due to their transient nature. Hence, molecular dynamics (MD) simulations have been performed on the His tautomeric isomers εε, εδ, δε, and δδ of PFN1 to explain the structural changes and to correlate them with its aggregation propensity. MD simulations show that His133 presumably plays a major role in the aggregation of PFN1 upon His tautomerism compared to His119. Further, the formation of a new 310-helix is observed in εε and δε but 310-helix is not observed in δδ and εδ isomers. In addition, our findings unveil that β-sheet dominating conformations are observed in His119(δ)-His133(δ) δδ isomer of PFN1 with significant antiparallel β-sheets between residues T15-G23, S29-A33, L63-L65, Q68-S76, F83-T89, T97-T105, and K107-K115, suggesting a novel aggregation mechanism possibly occur for the formation of PFN1 aggregates. Overall, these results propose that MD simulations of PFN1 His tautomers can provide a detailed microscopic understanding of the aggregation mechanisms which are hard to probe through experiments.
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Affiliation(s)
- Gurusamy Muneeswaran
- Department of Chemistry, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Jin Yong Lee
- Department of Chemistry, Sungkyunkwan University, Suwon 16419, Republic of Korea.
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21
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Pimm ML, Liu X, Tuli F, Heritz J, Lojko A, Henty-Ridilla JL. Visualizing molecules of functional human profilin. eLife 2022; 11:e76485. [PMID: 35666129 PMCID: PMC9249392 DOI: 10.7554/elife.76485] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Accepted: 06/06/2022] [Indexed: 11/20/2022] Open
Abstract
Profilin-1 (PFN1) is a cytoskeletal protein that regulates the dynamics of actin and microtubule assembly. Thus, PFN1 is essential for the normal division, motility, and morphology of cells. Unfortunately, conventional fusion and direct labeling strategies compromise different facets of PFN1 function. As a consequence, the only methods used to determine known PFN1 functions have been indirect and often deduced in cell-free biochemical assays. We engineered and characterized two genetically encoded versions of tagged PFN1 that behave identical to each other and the tag-free protein. In biochemical assays purified proteins bind to phosphoinositide lipids, catalyze nucleotide exchange on actin monomers, stimulate formin-mediated actin filament assembly, and bound tubulin dimers (kD = 1.89 µM) to impact microtubule dynamics. In PFN1-deficient mammalian cells, Halo-PFN1 or mApple-PFN1 (mAp-PEN1) restored morphological and cytoskeletal functions. Titrations of self-labeling Halo-ligands were used to visualize molecules of PFN1. This approach combined with specific function-disrupting point-mutants (Y6D and R88E) revealed PFN1 bound to microtubules in live cells. Cells expressing the ALS-associated G118V disease variant did not associate with actin filaments or microtubules. Thus, these tagged PFN1s are reliable tools for studying the dynamic interactions of PFN1 with actin or microtubules in vitro as well as in important cell processes or disease-states.
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Affiliation(s)
- Morgan L Pimm
- Department of Biochemistry and Molecular Biology, SUNY Upstate Medical UniversitySyracuseUnited States
| | - Xinbei Liu
- Department of Biochemistry and Molecular Biology, SUNY Upstate Medical UniversitySyracuseUnited States
| | - Farzana Tuli
- Department of Biochemistry and Molecular Biology, SUNY Upstate Medical UniversitySyracuseUnited States
| | - Jennifer Heritz
- Department of Biochemistry and Molecular Biology, SUNY Upstate Medical UniversitySyracuseUnited States
| | - Ashley Lojko
- Department of Biochemistry and Molecular Biology, SUNY Upstate Medical UniversitySyracuseUnited States
| | - Jessica L Henty-Ridilla
- Department of Biochemistry and Molecular Biology, SUNY Upstate Medical UniversitySyracuseUnited States
- Department of Neuroscience and Physiology, SUNY Upstate Medical UniversitySyracuseUnited States
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22
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Pushpalatha KV, Solyga M, Nakamura A, Besse F. RNP components condense into repressive RNP granules in the aging brain. Nat Commun 2022; 13:2782. [PMID: 35589695 PMCID: PMC9120078 DOI: 10.1038/s41467-022-30066-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Accepted: 04/11/2022] [Indexed: 12/21/2022] Open
Abstract
Cytoplasmic RNP condensates enriched in mRNAs and proteins are found in various cell types and associated with both buffering and regulatory functions. While a clear link has been established between accumulation of aberrant RNP aggregates and progression of aging-related neurodegenerative diseases, the impact of physiological aging on neuronal RNP condensates has never been explored. Through high-resolution imaging, we uncover that RNP components progressively cluster into large yet dynamic granules in the aging Drosophila brain. We further show that age-dependent clustering is caused by an increase in the stoichiometry of the conserved helicase Me31B/DDX6, and requires PKA kinase activity. Finally, our functional analysis reveals that mRNA species recruited to RNP condensates upon aging exhibit age-dependent translational repression, indicating that co-clustering of selected mRNAs and translation regulators into repressive condensates may contribute to the specific post-transcriptional changes in gene expression observed in the course of aging. Aberrant RNA condensates are a hallmark of age-related neurodegenerative diseases. Here, the authors show that RNA condensation increases in aging Drosophila brains, triggering translation repression.
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Affiliation(s)
| | - Mathilde Solyga
- Université Côte d'Azur, CNRS, Inserm, Institut de Biologie Valrose, Nice, France
| | - Akira Nakamura
- Department of Germline Development, Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto, Japan.,Graduate School of Pharmaceutical Sciences, Kumamoto University, Kumamoto, Japan
| | - Florence Besse
- Université Côte d'Azur, CNRS, Inserm, Institut de Biologie Valrose, Nice, France.
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23
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The Amyotrophic Lateral Sclerosis M114T PFN1 Mutation Deregulates Alternative Autophagy Pathways and Mitochondrial Homeostasis. Int J Mol Sci 2022; 23:ijms23105694. [PMID: 35628504 PMCID: PMC9143529 DOI: 10.3390/ijms23105694] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 05/13/2022] [Accepted: 05/15/2022] [Indexed: 12/10/2022] Open
Abstract
Mutations in profilin 1 (PFN1) have been identified in rare familial cases of Amyotrophic Lateral Sclerosis (ALS). PFN1 is involved in multiple pathways that could intervene in ALS pathology. However, the specific pathogenic role of PFN1 mutations in ALS is still not fully understood. We hypothesized that PFN1 could play a role in regulating autophagy pathways and that PFN1 mutations could disrupt this function. We used patient cells (lymphoblasts) or tissue (post-mortem) carrying PFN1 mutations (M114T and E117G), and designed experimental models expressing wild-type or mutant PFN1 (cell lines and novel PFN1 mice established by lentiviral transgenesis) to study the effects of PFN1 mutations on autophagic pathway markers. We observed no accumulation of PFN1 in the spinal cord of one E117G mutation carrier. Moreover, in patient lymphoblasts and transfected cell lines, the M114T mutant PFN1 protein was unstable and deregulated the RAB9-mediated alternative autophagy pathway involved in the clearance of damaged mitochondria. In vivo, motor neurons expressing M114T mutant PFN1 showed mitochondrial abnormalities. Our results demonstrate that the M114T PFN1 mutation is more deleterious than the E117G variant in patient cells and experimental models and suggest a role for the RAB9-dependent autophagic pathway in ALS.
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24
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Hu L, Mao S, Lin L, Bai G, Liu B, Mao J. Stress granules in the spinal muscular atrophy and amyotrophic lateral sclerosis: The correlation and promising therapy. Neurobiol Dis 2022; 170:105749. [PMID: 35568100 DOI: 10.1016/j.nbd.2022.105749] [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: 01/22/2022] [Revised: 03/27/2022] [Accepted: 05/05/2022] [Indexed: 10/18/2022] Open
Abstract
Increasing genetic and biochemical evidence has broadened our view of the pathomechanisms that lead to Spinal muscular atrophy (SMA) and Amyotrophic lateral sclerosis (ALS), two fatal neurodegenerative diseases with similar symptoms and causes. Stress granules are dynamic cytosolic storage hubs for mRNAs in response to stress exposures, that are evolutionarily conserved cytoplasmic RNA granules in somatic cells. A lot of previous studies have shown that the impaired stress granules are crucial events in SMA/ALS pathogenesis. In this review, we described the key stress granules related RNA binding proteins (SMN, TDP-43, and FUS) involved in SMA/ALS, summarized the reported mutations in these RNA binding proteins involved in SMA/ALS pathogenesis, and discussed the mechanisms through which stress granules dynamics participate in the diseases. Meanwhile, we described the applications and limitation of current therapies targeting SMA/ALS. We futher proposed the promising targets on stress granules in the future therapeutic interventions of SMA/ALS.
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Affiliation(s)
- LiDan Hu
- the Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou 310052, China.
| | - Shanshan Mao
- the Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou 310052, China
| | - Li Lin
- the Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou 310052, China
| | - Guannan Bai
- the Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou 310052, China
| | - Bingjie Liu
- State Key Laboratory of Membrane Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Jianhua Mao
- the Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou 310052, China
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25
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Kubinski S, Claus P. Protein Network Analysis Reveals a Functional Connectivity of Dysregulated Processes in ALS and SMA. Neurosci Insights 2022; 17:26331055221087740. [PMID: 35372839 PMCID: PMC8966079 DOI: 10.1177/26331055221087740] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Accepted: 02/28/2022] [Indexed: 01/09/2023] Open
Abstract
Spinal Muscular Atrophy (SMA) and Amyotrophic Lateral Sclerosis (ALS) are neurodegenerative diseases which are characterized by the loss of motoneurons within the central nervous system. SMA is a monogenic disease caused by reduced levels of the Survival of motoneuron protein, whereas ALS is a multi-genic disease with over 50 identified disease-causing genes and involvement of environmental risk factors. Although these diseases have different causes, they partially share identical phenotypes and pathomechanisms. To analyze and identify functional connections and to get a global overview of altered pathways in both diseases, protein network analyses are commonly used. Here, we used an in silico tool to test for functional associations between proteins that are involved in actin cytoskeleton dynamics, fatty acid metabolism, skeletal muscle metabolism, stress granule dynamics as well as SMA or ALS risk factors, respectively. In network biology, interactions are represented by edges which connect proteins (nodes). Our approach showed that only a few edges are necessary to present a complex protein network of different biological processes. Moreover, Superoxide dismutase 1, which is mutated in ALS, and the actin-binding protein profilin1 play a central role in the connectivity of the aforementioned pathways. Our network indicates functional links between altered processes that are described in either ALS or SMA. These links may not have been considered in the past but represent putative targets to restore altered processes and reveal overlapping pathomechanisms in both diseases.
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Affiliation(s)
- Sabrina Kubinski
- Institute of Neuroanatomy and Cell Biology, Hannover Medical School, Hannover, Germany
- Center for Systems Neuroscience (ZSN), Hannover, Germany
| | - Peter Claus
- Center for Systems Neuroscience (ZSN), Hannover, Germany
- SMATHERIA gGmbH – Non-Profit Biomedical Research Institute, Hannover, Germany
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26
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Davidson JM, Chung RS, Lee A. The converging roles of sequestosome-1/p62 in the molecular pathways of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Neurobiol Dis 2022; 166:105653. [PMID: 35143965 DOI: 10.1016/j.nbd.2022.105653] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Revised: 01/18/2022] [Accepted: 02/03/2022] [Indexed: 01/03/2023] Open
Abstract
Investigations into the pathogenetic mechanisms underlying amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) have provided significant insight into the disease. At the cellular level, ALS and FTD are classified as proteinopathies, which is motor neuron degeneration and death characterized by pathological protein aggregates or dysregulated proteostasis. At both the clinical and molecular level there are common signaling pathways dysregulated across the ALS and FTD spectrum (ALS/FTD). Sequestosome-1/p62 is a multifunctional scaffold protein with roles in several signaling pathways including proteostasis, protein degradation via the ubiquitin proteasome system and autophagy, the antioxidant response, inflammatory response, and apoptosis. Notably these pathways are dysregulated in ALS and FTD. Mutations in the functional domains of p62 provide links to the pathogenetic mechanisms of p62 and dyshomeostasis of p62 levels is noted in several types of ALS and FTD. We present here that the dysregulated ALS and FTD signaling pathways are linked, with p62 converging the molecular mechanisms. This review summarizes the current literature on the complex role of p62 in the pathogenesis across the ALS/FTD spectrum. The focus is on the underlying convergent molecular mechanisms of ALS and FTD-associated proteins and pathways that dysregulate p62 levels or are dysregulated by p62, with emphasis on how p62 is implicated across the ALS/FTD spectrum.
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Affiliation(s)
- Jennilee M Davidson
- Centre for Motor Neuron Disease Research, Macquarie Medical School, Faculty of Medicine, Health and Human Sciences, Macquarie University, 2 Technology Place, NSW 2109, Australia..
| | - Roger S Chung
- Centre for Motor Neuron Disease Research, Macquarie Medical School, Faculty of Medicine, Health and Human Sciences, Macquarie University, 2 Technology Place, NSW 2109, Australia..
| | - Albert Lee
- Centre for Motor Neuron Disease Research, Macquarie Medical School, Faculty of Medicine, Health and Human Sciences, Macquarie University, 2 Technology Place, NSW 2109, Australia..
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27
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Carey JL, Guo L. Liquid-Liquid Phase Separation of TDP-43 and FUS in Physiology and Pathology of Neurodegenerative Diseases. Front Mol Biosci 2022; 9:826719. [PMID: 35187086 PMCID: PMC8847598 DOI: 10.3389/fmolb.2022.826719] [Citation(s) in RCA: 62] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 01/11/2022] [Indexed: 12/12/2022] Open
Abstract
Liquid-liquid phase separation of RNA-binding proteins mediates the formation of numerous membraneless organelles with essential cellular function. However, aberrant phase transition of these proteins leads to the formation of insoluble protein aggregates, which are pathological hallmarks of neurodegenerative diseases including ALS and FTD. TDP-43 and FUS are two such RNA-binding proteins that mislocalize and aggregate in patients of ALS and FTD. They have similar domain structures that provide multivalent interactions driving their phase separation in vitro and in the cellular environment. In this article, we review the factors that mediate and regulate phase separation of TDP-43 and FUS. We also review evidences that connect the phase separation property of TDP-43 and FUS to their functional roles in cells. Aberrant phase transition of TDP-43 and FUS leads to protein aggregation and disrupts their regular cell function. Therefore, restoration of functional protein phase of TDP-43 and FUS could be beneficial for neuronal cells. We discuss possible mechanisms for TDP-43 and FUS aberrant phase transition and aggregation while reviewing the methods that are currently being explored as potential therapeutic strategies to mitigate aberrant phase transition and aggregation of TDP-43 and FUS.
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28
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Liu X, Pimm ML, Haarer B, Brawner AT, Henty-Ridilla JL. Biochemical characterization of actin assembly mechanisms with ALS-associated profilin variants. Eur J Cell Biol 2022; 101:151212. [PMID: 35248815 PMCID: PMC10163920 DOI: 10.1016/j.ejcb.2022.151212] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 02/23/2022] [Accepted: 02/25/2022] [Indexed: 12/26/2022] Open
Abstract
Eight separate mutations in the actin-binding protein profilin-1 have been identified as a rare cause of amyotrophic lateral sclerosis (ALS). Profilin is essential for many neuronal cell processes through its regulation of lipids, nuclear signals, and cytoskeletal dynamics, including actin filament assembly. Direct interactions between profilin and actin monomers inhibit actin filament polymerization. In contrast, profilin can also stimulate polymerization by simultaneously binding actin monomers and proline-rich tracts found in other proteins. Whether the ALS-associated mutations in profilin compromise these actin assembly functions is unclear. We performed a quantitative biochemical comparison of the direct and formin mediated impact for the eight ALS-associated profilin variants on actin assembly using classic protein-binding and single-filament microscopy assays. We determined that the binding constant of each profilin for actin monomers generally correlates with the actin nucleation strength associated with each ALS-related profilin. In the presence of formin, the A20T, R136W, Q139L, and C71G variants failed to activate the elongation phase of actin assembly. This diverse range of formin-activities is not fully explained through profilin-poly-L-proline (PLP) interactions, as all ALS-associated variants bind a formin-derived PLP peptide with similar affinities. However, chemical denaturation experiments suggest that the folding stability of these profilins impact some of these effects on actin assembly. Thus, changes in profilin protein stability and alterations in actin filament polymerization may both contribute to the profilin-mediated actin disruptions in ALS.
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Affiliation(s)
- Xinbei Liu
- Department of Biochemistry & Molecular Biology, SUNY Upstate Medical University, Syracuse, NY 13210, USA
| | - Morgan L Pimm
- Department of Biochemistry & Molecular Biology, SUNY Upstate Medical University, Syracuse, NY 13210, USA
| | - Brian Haarer
- Department of Biochemistry & Molecular Biology, SUNY Upstate Medical University, Syracuse, NY 13210, USA
| | - Andrew T Brawner
- Department of Neuroscience & Physiology, SUNY Upstate Medical University, Syracuse, NY 13210, USA
| | - Jessica L Henty-Ridilla
- Department of Biochemistry & Molecular Biology, SUNY Upstate Medical University, Syracuse, NY 13210, USA; Department of Neuroscience & Physiology, SUNY Upstate Medical University, Syracuse, NY 13210, USA.
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29
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Sundberg CA, Lakk M, Paul S, Figueroa KP, Scoles DR, Pulst SM, Križaj D. The RNA-binding protein and stress granule component ATAXIN-2 is expressed in mouse and human tissues associated with glaucoma pathogenesis. J Comp Neurol 2022; 530:537-552. [PMID: 34350994 PMCID: PMC8716417 DOI: 10.1002/cne.25228] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Accepted: 07/06/2021] [Indexed: 02/03/2023]
Abstract
Polyglutamine repeat expansions in the Ataxin-2 (ATXN2) gene were first implicated in Spinocerebellar Ataxia Type 2, a disease associated with degeneration of motor neurons and Purkinje cells. Recent studies linked single nucleotide polymorphisms in the gene to elevated intraocular pressure in primary open angle glaucoma (POAG); yet, the localization of ATXN2 across glaucoma-relevant tissues of the vertebrate eye has not been thoroughly examined. This study characterizes ATXN2 expression in the mouse and human retina, and anterior eye, using an antibody validated in ATXN2-/- retinas. ATXN2-ir was localized to cytosolic sub compartments in retinal ganglion cell (RGC) somata and proximal dendrites in addition to GABAergic, glycinergic, and cholinergic amacrine cells in the inner plexiform layer (IPL) and displaced amacrine cells. Human, but not mouse retinas showed modest immunolabeling of bipolar cells. ATXN2 immunofluorescence was prominent in the trabecular meshwork and pigmented and nonpigmented cells of the ciliary body, with analyses of primary human trabecular meshwork cells confirming the finding. The expression of ATXN2 in key POAG-relevant ocular tissues supports the potential role in autophagy and stress granule formation in response to ocular hypertension.
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Affiliation(s)
- Chad A. Sundberg
- Department of Ophthalmology & Visual Sciences, University of Utah, Salt Lake City, Utah, USA
- Department of Neurology, University of Utah, Salt Lake City, Utah, USA
| | - Monika Lakk
- Department of Ophthalmology & Visual Sciences, University of Utah, Salt Lake City, Utah, USA
| | - Sharan Paul
- Department of Neurology, University of Utah, Salt Lake City, Utah, USA
| | - Karla P. Figueroa
- Department of Neurology, University of Utah, Salt Lake City, Utah, USA
| | - Daniel R. Scoles
- Department of Neurology, University of Utah, Salt Lake City, Utah, USA
| | - Stefan M. Pulst
- Department of Neurology, University of Utah, Salt Lake City, Utah, USA
| | - David Križaj
- Department of Ophthalmology & Visual Sciences, University of Utah, Salt Lake City, Utah, USA
- Department of Bioengineering, University of Utah, Salt Lake City, Utah, USA
- Department of Neurobiology & Anatomy, University of Utah, Salt Lake City, Utah, USA
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30
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Del Castillo U, Norkett R, Lu W, Serpinskaya A, Gelfand VI. Ataxin-2 is essential for cytoskeletal dynamics and neurodevelopment in Drosophila. iScience 2022; 25:103536. [PMID: 34977501 PMCID: PMC8689088 DOI: 10.1016/j.isci.2021.103536] [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: 04/30/2021] [Revised: 08/19/2021] [Accepted: 11/25/2021] [Indexed: 12/03/2022] Open
Abstract
Ataxin-2 (Atx2) is a highly conserved RNA binding protein. Atx2 undergoes polyglutamine expansion leading to amyotrophic lateral sclerosis (ALS) or spinocerebellar ataxia type 2 (SCA2). However, the physiological functions of Atx2 in neurons remain unknown. Here, using the powerful genetics of Drosophila, we show that Atx2 is essential for normal neuronal cytoskeletal dynamics and organelle trafficking. Upon neuron-specific Atx2 loss, the microtubule and actin networks were abnormally stabilized and cargo transport was drastically inhibited. Depletion of Atx2 caused multiple morphological defects in the nervous system of third instar larvae. These include reduced brain size, impaired axon development, and decreased dendrite outgrowth. Defects in the nervous system caused loss of the ability to crawl and lethality at the pupal stage. Taken together, these data mark Atx2 as a major regulator of cytoskeletal dynamics and denote Atx2 as an essential gene in neurodevelopment, as well as a neurodegenerative factor. Atx2 is a major regulator of the cytoskeleton in neurons Atx2 is responsible for maintaining dynamic cytoskeletal networks Atx2 depletion in the Drosophila larval CNS severely impairs organelle transport Atx2 is necessary for correct neurite outgrowth and CNS development in Drosophila
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Affiliation(s)
- Urko Del Castillo
- Department of Cell and Developmental Biology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Rosalind Norkett
- Department of Cell and Developmental Biology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Wen Lu
- Department of Cell and Developmental Biology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Anna Serpinskaya
- Department of Cell and Developmental Biology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Vladimir I Gelfand
- Department of Cell and Developmental Biology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
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31
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Freibaum BD, Messing J, Yang P, Kim HJ, Taylor JP. High-fidelity reconstitution of stress granules and nucleoli in mammalian cellular lysate. J Cell Biol 2021; 220:211726. [PMID: 33502444 PMCID: PMC7845923 DOI: 10.1083/jcb.202009079] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 12/09/2020] [Accepted: 12/28/2020] [Indexed: 01/08/2023] Open
Abstract
Liquid–liquid phase separation (LLPS) is a mechanism of intracellular organization that underlies the assembly of a variety of RNP granules. Fundamental biophysical principles governing LLPS during granule assembly have been revealed by simple in vitro systems, but these systems have limitations when studying the biology of complex, multicomponent RNP granules. Visualization of RNP granules in cells has validated key principles revealed by simple in vitro systems, but this approach presents difficulties for interrogating biophysical features of RNP granules and provides limited ability to manipulate protein, nucleic acid, or small molecule concentrations. Here, we introduce a system that builds upon recent insights into the mechanisms underlying RNP granule assembly and permits high-fidelity reconstitution of stress granules and the granular component of nucleoli in mammalian cellular lysate. This system fills the gap between simple in vitro systems and live cells and allows for a variety of studies of membraneless organelles, including the development of therapeutics that modify properties of specific condensates.
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Affiliation(s)
- Brian D Freibaum
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, TN
| | - James Messing
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, TN.,Howard Hughes Medical Institute, Chevy Chase, MD
| | - Peiguo Yang
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, TN
| | - Hong Joo Kim
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, TN
| | - J Paul Taylor
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, TN.,Howard Hughes Medical Institute, Chevy Chase, MD
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32
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Murk K, Ornaghi M, Schiweck J. Profilin Isoforms in Health and Disease - All the Same but Different. Front Cell Dev Biol 2021; 9:681122. [PMID: 34458253 PMCID: PMC8387879 DOI: 10.3389/fcell.2021.681122] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Accepted: 07/12/2021] [Indexed: 12/11/2022] Open
Abstract
Profilins are small actin binding proteins, which are structurally conserved throughout evolution. They are probably best known to promote and direct actin polymerization. However, they also participate in numerous cell biological processes beyond the roles typically ascribed to the actin cytoskeleton. Moreover, most complex organisms express several profilin isoforms. Their cellular functions are far from being understood, whereas a growing number of publications indicate that profilin isoforms are involved in the pathogenesis of various diseases. In this review, we will provide an overview of the profilin family and "typical" profilin properties including the control of actin dynamics. We will then discuss the profilin isoforms of higher animals in detail. In terms of cellular functions, we will focus on the role of Profilin 1 (PFN1) and Profilin 2a (PFN2a), which are co-expressed in the central nervous system. Finally, we will discuss recent findings that link PFN1 and PFN2a to neurological diseases, such as amyotrophic lateral sclerosis (ALS), Fragile X syndrome (FXS), Huntington's disease and spinal muscular atrophy (SMA).
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Affiliation(s)
- Kai Murk
- Institute of Biochemistry, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Marta Ornaghi
- Institute of Biochemistry, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Juliane Schiweck
- Institute of Biochemistry, Charité Universitätsmedizin Berlin, Berlin, Germany
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33
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Fagan SG, Helm M, Prehn JHM. tRNA-derived fragments: A new class of non-coding RNA with key roles in nervous system function and dysfunction. Prog Neurobiol 2021; 205:102118. [PMID: 34245849 DOI: 10.1016/j.pneurobio.2021.102118] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Revised: 06/30/2021] [Accepted: 07/06/2021] [Indexed: 01/12/2023]
Abstract
tRNA-derived small RNAs (tsRNA) are a recently identified family of non-coding RNA that have been associated with a variety of cellular functions including the regulation of protein translation and gene expression. Recent sequencing and bioinformatic studies have identified the broad spectrum of tsRNA in the nervous system and demonstrated that this new class of non-coding RNA is produced from tRNA by specific cleavage events catalysed by ribonucleases such as angiogenin and dicer. Evidence is also accumulating that production of tsRNA is increased during disease processes where they regulate stress responses, proteostasis, and neuronal survival. Mutations to tRNA cleaving and modifying enzymes have been implicated in several neurodegenerative disorders, and tsRNA levels in the blood are advancing as biomarkers for neurological disease. In this review we summarize the physiological importance of tsRNA in the central nervous system and their relevance to neurological disease.
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Affiliation(s)
- Steven G Fagan
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, St. Stephen'S Green, Dublin 2, Ireland; SFI FutureNeuro Research Centre, Royal College of Surgeons in Ireland, St. Stephen's Green, Dublin 2, Ireland
| | - Mark Helm
- Institute of Pharmaceutical and Biomedical Sciences - IPBS, Johannes Gutenberg-University, 55128, Mainz, Germany
| | - Jochen H M Prehn
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, St. Stephen'S Green, Dublin 2, Ireland; SFI FutureNeuro Research Centre, Royal College of Surgeons in Ireland, St. Stephen's Green, Dublin 2, Ireland.
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34
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Gwon Y, Maxwell BA, Kolaitis RM, Zhang P, Kim HJ, Taylor JP. Ubiquitination of G3BP1 mediates stress granule disassembly in a context-specific manner. Science 2021; 372:eabf6548. [PMID: 34739333 PMCID: PMC8574224 DOI: 10.1126/science.abf6548] [Citation(s) in RCA: 136] [Impact Index Per Article: 45.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Stress granules are dynamic, reversible condensates composed of RNA and protein that assemble in eukaryotic cells in response to a variety of stressors and are normally disassembled after stress is removed. The composition and assembly of stress granules is well understood, but little is known about the mechanisms that govern disassembly. Impaired disassembly has been implicated in some diseases including amyotrophic lateral sclerosis, frontotemporal dementia, and multisystem proteinopathy. Using cultured human cells, we found that stress granule disassembly was context-dependent: Specifically in the setting of heat shock, disassembly required ubiquitination of G3BP1, the central protein within the stress granule RNA-protein network. We found that ubiquitinated G3BP1 interacted with the endoplasmic reticulum–associated protein FAF2, which engaged the ubiquitin-dependent segregase p97/VCP (valosin-containing protein). Thus, targeting of G3BP1 weakened the stress granule–specific interaction network, resulting in granule disassembly.
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Affiliation(s)
- Youngdae Gwon
- Department of Cell and Molecular Biology, St. Jude Children’s Research Hospital, Memphis, TN, USA
| | - Brian A. Maxwell
- Department of Cell and Molecular Biology, St. Jude Children’s Research Hospital, Memphis, TN, USA
| | - Regina-Maria Kolaitis
- Department of Cell and Molecular Biology, St. Jude Children’s Research Hospital, Memphis, TN, USA
| | - Peipei Zhang
- Department of Cell and Molecular Biology, St. Jude Children’s Research Hospital, Memphis, TN, USA
| | - Hong Joo Kim
- Department of Cell and Molecular Biology, St. Jude Children’s Research Hospital, Memphis, TN, USA
| | - J. Paul Taylor
- Department of Cell and Molecular Biology, St. Jude Children’s Research Hospital, Memphis, TN, USA
- Howard Hughes Medical Institute, Chevy Chase, MD 20815
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35
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Maxwell BA, Gwon Y, Mishra A, Peng J, Nakamura H, Zhang K, Kim HJ, Taylor JP. Ubiquitination is essential for recovery of cellular activities after heat shock. Science 2021; 372:eabc3593. [PMID: 34739326 PMCID: PMC8574219 DOI: 10.1126/science.abc3593] [Citation(s) in RCA: 83] [Impact Index Per Article: 27.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/07/2023]
Abstract
Eukaryotic cells respond to stress through adaptive programs that include reversible shutdown of key cellular processes, the formation of stress granules, and a global increase in ubiquitination. The primary function of this ubiquitination is thought to be for tagging damaged or misfolded proteins for degradation. Here, working in mammalian cultured cells, we found that different stresses elicited distinct ubiquitination patterns. For heat stress, ubiquitination targeted specific proteins associated with cellular activities that are down-regulated during stress, including nucleocytoplasmic transport and translation, as well as stress granule constituents. Ubiquitination was not required for the shutdown of these processes or for stress granule formation but was essential for the resumption of cellular activities and for stress granule disassembly. Thus, stress-induced ubiquitination primes the cell for recovery after heat stress.
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Affiliation(s)
- Brian A. Maxwell
- Department of Cell and Molecular Biology, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
| | - Youngdae Gwon
- Department of Cell and Molecular Biology, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
| | - Ashutosh Mishra
- Department of Structural Biology Department, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
| | - Junmin Peng
- Department of Structural Biology Department, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
| | - Haruko Nakamura
- Department of Cell and Molecular Biology, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
| | - Ke Zhang
- Department of Neuroscience, Mayo Clinic Florida, Jacksonville, FL 32224, USA
| | - Hong Joo Kim
- Department of Cell and Molecular Biology, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
| | - J. Paul Taylor
- Department of Cell and Molecular Biology, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
- Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA
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36
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ALS-linked PFN1 variants exhibit loss and gain of functions in the context of formin-induced actin polymerization. Proc Natl Acad Sci U S A 2021; 118:2024605118. [PMID: 34074767 DOI: 10.1073/pnas.2024605118] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Profilin-1 (PFN1) plays important roles in modulating actin dynamics through binding both monomeric actin and proteins enriched with polyproline motifs. Mutations in PFN1 have been linked to the neurodegenerative disease amyotrophic lateral sclerosis (ALS). However, whether ALS-linked mutations affect PFN1 function has remained unclear. To address this question, we employed an unbiased proteomics analysis in mammalian cells to identify proteins that differentially interact with mutant and wild-type (WT) PFN1. These studies uncovered differential binding between two ALS-linked PFN1 variants, G118V and M114T, and select formin proteins. Furthermore, both variants augmented formin-mediated actin assembly relative to PFN1 WT. Molecular dynamics simulations revealed mutation-induced changes in the internal dynamic couplings within an alpha helix of PFN1 that directly contacts both actin and polyproline, as well as structural fluctuations within the actin- and polyproline-binding regions of PFN1. These data indicate that ALS-PFN1 variants have the potential for heightened flexibility in the context of the ternary actin-PFN1-polyproline complex during actin assembly. Conversely, PFN1 C71G was more severely destabilized than the other PFN1 variants, resulting in reduced protein expression in both transfected and ALS patient lymphoblast cell lines. Moreover, this variant exhibited loss-of-function phenotypes in the context of actin assembly. Perturbations in actin dynamics and assembly can therefore result from ALS-linked mutations in PFN1. However, ALS-PFN1 variants may dysregulate actin polymerization through different mechanisms that depend upon the solubility and stability of the mutant protein.
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37
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Connecting the "dots": RNP granule network in health and disease. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2021; 1868:119058. [PMID: 33989700 DOI: 10.1016/j.bbamcr.2021.119058] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 01/17/2021] [Revised: 05/01/2021] [Accepted: 05/07/2021] [Indexed: 12/26/2022]
Abstract
All cells contain ribonucleoprotein (RNP) granules - large membraneless structures composed of RNA and proteins. Recent breakthroughs in RNP granule research have brought a new appreciation of their crucial role in organising virtually all cellular processes. Cells widely exploit the flexible, dynamic nature of RNP granules to adapt to a variety of functional states and the ever-changing environment. Constant exchange of molecules between the different RNP granules connects them into a network. This network controls basal cellular activities and is remodelled to enable efficient stress response. Alterations in RNP granule structure and regulation have been found to lead to fatal human diseases. The interconnectedness of RNP granules suggests that the RNP granule network as a whole becomes affected in disease states such as a representative neurodegenerative disease amyotrophic lateral sclerosis (ALS). In this review, we summarize available evidence on the communication between different RNP granules and on the RNP granule network disruption as a primary ALS pathomechanism.
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Kim W, Kim DY, Lee KH. RNA-Binding Proteins and the Complex Pathophysiology of ALS. Int J Mol Sci 2021; 22:ijms22052598. [PMID: 33807542 PMCID: PMC7961459 DOI: 10.3390/ijms22052598] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 02/26/2021] [Accepted: 03/01/2021] [Indexed: 12/21/2022] Open
Abstract
Genetic analyses of patients with amyotrophic lateral sclerosis (ALS) have identified disease-causing mutations and accelerated the unveiling of complex molecular pathogenic mechanisms, which may be important for understanding the disease and developing therapeutic strategies. Many disease-related genes encode RNA-binding proteins, and most of the disease-causing RNA or proteins encoded by these genes form aggregates and disrupt cellular function related to RNA metabolism. Disease-related RNA or proteins interact or sequester other RNA-binding proteins. Eventually, many disease-causing mutations lead to the dysregulation of nucleocytoplasmic shuttling, the dysfunction of stress granules, and the altered dynamic function of the nucleolus as well as other membrane-less organelles. As RNA-binding proteins are usually components of several RNA-binding protein complexes that have other roles, the dysregulation of RNA-binding proteins tends to cause diverse forms of cellular dysfunction. Therefore, understanding the role of RNA-binding proteins will help elucidate the complex pathophysiology of ALS. Here, we summarize the current knowledge regarding the function of disease-associated RNA-binding proteins and their role in the dysfunction of membrane-less organelles.
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Affiliation(s)
- Wanil Kim
- Division of Cosmetic Science and Technology, Daegu Haany University, Hanuidae-ro 1, Gyeongsan, Gyeongbuk 38610, Korea;
| | - Do-Yeon Kim
- Department of Pharmacology, School of Dentistry, Kyungpook National University, Daegu 41940, Korea
- Correspondence: (D.-Y.K.); (K.-H.L.); Tel.: +82-53-660-6880 (D.-Y.K.); +82-53-819-7743 (K.-H.L.)
| | - Kyung-Ha Lee
- Division of Cosmetic Science and Technology, Daegu Haany University, Hanuidae-ro 1, Gyeongsan, Gyeongbuk 38610, Korea;
- Correspondence: (D.-Y.K.); (K.-H.L.); Tel.: +82-53-660-6880 (D.-Y.K.); +82-53-819-7743 (K.-H.L.)
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Yang P, Mathieu C, Kolaitis RM, Zhang P, Messing J, Yurtsever U, Yang Z, Wu J, Li Y, Pan Q, Yu J, Martin EW, Mittag T, Kim HJ, Taylor JP. G3BP1 Is a Tunable Switch that Triggers Phase Separation to Assemble Stress Granules. Cell 2020; 181:325-345.e28. [PMID: 32302571 DOI: 10.1016/j.cell.2020.03.046] [Citation(s) in RCA: 626] [Impact Index Per Article: 156.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Revised: 10/23/2019] [Accepted: 03/20/2020] [Indexed: 12/18/2022]
Abstract
The mechanisms underlying ribonucleoprotein (RNP) granule assembly, including the basis for establishing and maintaining RNP granules with distinct composition, are unknown. One prominent type of RNP granule is the stress granule (SG), a dynamic and reversible cytoplasmic assembly formed in eukaryotic cells in response to stress. Here, we show that SGs assemble through liquid-liquid phase separation (LLPS) arising from interactions distributed unevenly across a core protein-RNA interaction network. The central node of this network is G3BP1, which functions as a molecular switch that triggers RNA-dependent LLPS in response to a rise in intracellular free RNA concentrations. Moreover, we show that interplay between three distinct intrinsically disordered regions (IDRs) in G3BP1 regulates its intrinsic propensity for LLPS, and this is fine-tuned by phosphorylation within the IDRs. Further regulation of SG assembly arises through positive or negative cooperativity by extrinsic G3BP1-binding factors that strengthen or weaken, respectively, the core SG network.
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Affiliation(s)
- Peiguo Yang
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Cécile Mathieu
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA; Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA
| | - Regina-Maria Kolaitis
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Peipei Zhang
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - James Messing
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA; Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA
| | - Ugur Yurtsever
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA; Graduate School of Structure and Dynamics of Living Systems, Université Paris-Saclay, Gif-sur-Yvette, 91190, France
| | - Zemin Yang
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Jinjun Wu
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Yuxin Li
- Center for Proteomics and Metabolomics, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Qingfei Pan
- Department of Computational Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Jiyang Yu
- Department of Computational Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Erik W Martin
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Tanja Mittag
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Hong Joo Kim
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - J Paul Taylor
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA; Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA.
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Lee AK, Klein J, Fon Tacer K, Lord T, Oatley MJ, Oatley JM, Porter SN, Pruett-Miller SM, Tikhonova EB, Karamyshev AL, Wang YD, Yang P, Korff A, Kim HJ, Taylor JP, Potts PR. Translational Repression of G3BP in Cancer and Germ Cells Suppresses Stress Granules and Enhances Stress Tolerance. Mol Cell 2020; 79:645-659.e9. [PMID: 32692974 DOI: 10.1016/j.molcel.2020.06.037] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Revised: 05/10/2020] [Accepted: 06/29/2020] [Indexed: 02/08/2023]
Abstract
Stress granules (SGs) are membrane-less ribonucleoprotein condensates that form in response to various stress stimuli via phase separation. SGs act as a protective mechanism to cope with acute stress, but persistent SGs have cytotoxic effects that are associated with several age-related diseases. Here, we demonstrate that the testis-specific protein, MAGE-B2, increases cellular stress tolerance by suppressing SG formation through translational inhibition of the key SG nucleator G3BP. MAGE-B2 reduces G3BP protein levels below the critical concentration for phase separation and suppresses SG initiation. Knockout of the MAGE-B2 mouse ortholog or overexpression of G3BP1 confers hypersensitivity of the male germline to heat stress in vivo. Thus, MAGE-B2 provides cytoprotection to maintain mammalian spermatogenesis, a highly thermosensitive process that must be preserved throughout reproductive life. These results demonstrate a mechanism that allows for tissue-specific resistance against stress and could aid in the development of male fertility therapies.
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Affiliation(s)
- Anna K Lee
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Jonathon Klein
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Klementina Fon Tacer
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Tessa Lord
- Center for Reproductive Biology, College of Veterinary Medicine, Washington State University, Pullman, WA, USA
| | - Melissa J Oatley
- Center for Reproductive Biology, College of Veterinary Medicine, Washington State University, Pullman, WA, USA
| | - Jon M Oatley
- Center for Reproductive Biology, College of Veterinary Medicine, Washington State University, Pullman, WA, USA
| | - Shaina N Porter
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Shondra M Pruett-Miller
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Elena B Tikhonova
- Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - Andrey L Karamyshev
- Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - Yong-Dong Wang
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Peiguo Yang
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Ane Korff
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Hong Joo Kim
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - J Paul Taylor
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, TN, USA; Howard Hughes Medical Institute, Chevy Chase, MD, USA
| | - Patrick Ryan Potts
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, TN, USA.
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Pimm ML, Hotaling J, Henty-Ridilla JL. Profilin choreographs actin and microtubules in cells and cancer. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2020; 355:155-204. [PMID: 32859370 PMCID: PMC7461721 DOI: 10.1016/bs.ircmb.2020.05.005] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Actin and microtubules play essential roles in aberrant cell processes that define and converge in cancer including: signaling, morphology, motility, and division. Actin and microtubules do not directly interact, however shared regulators coordinate these polymers. While many of the individual proteins important for regulating and choreographing actin and microtubule behaviors have been identified, the way these molecules collaborate or fail in normal or disease contexts is not fully understood. Decades of research focus on Profilin as a signaling molecule, lipid-binding protein, and canonical regulator of actin assembly. Recent reports demonstrate that Profilin also regulates microtubule dynamics and polymerization. Thus, Profilin can coordinate both actin and microtubule polymer systems. Here we reconsider the biochemical and cellular roles for Profilin with a focus on the essential cytoskeletal-based cell processes that go awry in cancer. We also explore how the use of model organisms has helped to elucidate mechanisms that underlie the regulatory essence of Profilin in vivo and in the context of disease.
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Affiliation(s)
- Morgan L Pimm
- Department of Cell and Developmental Biology, State University of New York (SUNY) Upstate Medical University, Syracuse, NY, United States
| | - Jessica Hotaling
- Department of Cell and Developmental Biology, State University of New York (SUNY) Upstate Medical University, Syracuse, NY, United States
| | - Jessica L Henty-Ridilla
- Department of Cell and Developmental Biology, State University of New York (SUNY) Upstate Medical University, Syracuse, NY, United States; Department of Biochemistry and Molecular Biology, State University of New York (SUNY) Upstate Medical University, Syracuse, NY, United States.
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42
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Chernoff YO, Grizel AV, Rubel AA, Zelinsky AA, Chandramowlishwaran P, Chernova TA. Application of yeast to studying amyloid and prion diseases. ADVANCES IN GENETICS 2020; 105:293-380. [PMID: 32560789 PMCID: PMC7527210 DOI: 10.1016/bs.adgen.2020.01.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Amyloids are fibrous cross-β protein aggregates that are capable of proliferation via nucleated polymerization. Amyloid conformation likely represents an ancient protein fold and is linked to various biological or pathological manifestations. Self-perpetuating amyloid-based protein conformers provide a molecular basis for transmissible (infectious or heritable) protein isoforms, termed prions. Amyloids and prions, as well as other types of misfolded aggregated proteins are associated with a variety of devastating mammalian and human diseases, such as Alzheimer's, Parkinson's and Huntington's diseases, transmissible spongiform encephalopathies (TSEs), amyotrophic lateral sclerosis (ALS) and transthyretinopathies. In yeast and fungi, amyloid-based prions control phenotypically detectable heritable traits. Simplicity of cultivation requirements and availability of powerful genetic approaches makes yeast Saccharomyces cerevisiae an excellent model system for studying molecular and cellular mechanisms governing amyloid formation and propagation. Genetic techniques allowing for the expression of mammalian or human amyloidogenic and prionogenic proteins in yeast enable researchers to capitalize on yeast advantages for characterization of the properties of disease-related proteins. Chimeric constructs employing mammalian and human aggregation-prone proteins or domains, fused to fluorophores or to endogenous yeast proteins allow for cytological or phenotypic detection of disease-related protein aggregation in yeast cells. Yeast systems are amenable to high-throughput screening for antagonists of amyloid formation, propagation and/or toxicity. This review summarizes up to date achievements of yeast assays in application to studying mammalian and human disease-related aggregating proteins, and discusses both limitations and further perspectives of yeast-based strategies.
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Affiliation(s)
- Yury O Chernoff
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, United States; Laboratory of Amyloid Biology, St. Petersburg State University, St. Petersburg, Russia.
| | - Anastasia V Grizel
- Laboratory of Amyloid Biology, St. Petersburg State University, St. Petersburg, Russia
| | - Aleksandr A Rubel
- Laboratory of Amyloid Biology, St. Petersburg State University, St. Petersburg, Russia; Department of Genetics and Biotechnology, St. Petersburg State University, St. Petersburg, Russia; Sirius University of Science and Technology, Sochi, Russia
| | - Andrew A Zelinsky
- Laboratory of Amyloid Biology, St. Petersburg State University, St. Petersburg, Russia
| | | | - Tatiana A Chernova
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA, United States
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43
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Disease-modifying therapies in amyotrophic lateral sclerosis. Neuropharmacology 2020; 167:107986. [DOI: 10.1016/j.neuropharm.2020.107986] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Revised: 01/21/2020] [Accepted: 01/31/2020] [Indexed: 02/08/2023]
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44
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Baron DM, Matheny T, Lin YC, Leszyk JD, Kenna K, Gall KV, Santos DP, Tischbein M, Funes S, Hayward LJ, Kiskinis E, Landers JE, Parker R, Shaffer SA, Bosco DA. Quantitative proteomics identifies proteins that resist translational repression and become dysregulated in ALS-FUS. Hum Mol Genet 2020; 28:2143-2160. [PMID: 30806671 DOI: 10.1093/hmg/ddz048] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Revised: 02/01/2019] [Accepted: 02/07/2019] [Indexed: 12/13/2022] Open
Abstract
Aberrant translational repression is a feature of multiple neurodegenerative diseases. The association between disease-linked proteins and stress granules further implicates impaired stress responses in neurodegeneration. However, our knowledge of the proteins that evade translational repression is incomplete. It is also unclear whether disease-linked proteins influence the proteome under conditions of translational repression. To address these questions, a quantitative proteomics approach was used to identify proteins that evade stress-induced translational repression in arsenite-treated cells expressing either wild-type or amyotrophic lateral sclerosis (ALS)-linked mutant FUS. This study revealed hundreds of proteins that are actively synthesized during stress-induced translational repression, irrespective of FUS genotype. In addition to proteins involved in RNA- and protein-processing, proteins associated with neurodegenerative diseases such as ALS were also actively synthesized during stress. Protein synthesis under stress was largely unperturbed by mutant FUS, although several proteins were found to be differentially expressed between mutant and control cells. One protein in particular, COPBI, was downregulated in mutant FUS-expressing cells under stress. COPBI is the beta subunit of the coat protein I (COPI), which is involved in Golgi to endoplasmic reticulum (ER) retrograde transport. Further investigation revealed reduced levels of other COPI subunit proteins and defects in COPBI-relatedprocesses in cells expressing mutant FUS. Even in the absence of stress, COPBI localization was altered in primary and human stem cell-derived neurons expressing ALS-linked FUS variants. Our results suggest that Golgi to ER retrograde transport may be important under conditions of stress and is perturbed upon the expression of disease-linked proteins such as FUS.
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Affiliation(s)
- Desiree M Baron
- Department of Neurology, University of Massachusetts Medical School, Worcester, MA, USA
| | - Tyler Matheny
- Department of Chemistry and Biochemistry, University of Colorado, Boulder, CO, USA
| | - Yen-Chen Lin
- Department of Neurology, University of Massachusetts Medical School, Worcester, MA, USA
| | - John D Leszyk
- Department of Biochemistry and Molecular Pharmacology, Worcester, MA, USA.,Mass Spectrometry Facility, University of Massachusetts Medical School, Shrewsbury, MA, USA
| | - Kevin Kenna
- Department of Neurology, University of Massachusetts Medical School, Worcester, MA, USA.,Department of Neurology, Brain Center Rudolf Magnus, University Medical Center Utrecht, University of Utrecht, Utrecht, The Netherlands
| | - Katherine V Gall
- Department of Neurology, University of Massachusetts Medical School, Worcester, MA, USA
| | - David P Santos
- The Ken & Ruth Davee Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.,Department of Physiology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Maeve Tischbein
- Department of Neurology, University of Massachusetts Medical School, Worcester, MA, USA
| | - Salome Funes
- Department of Neurology, University of Massachusetts Medical School, Worcester, MA, USA
| | - Lawrence J Hayward
- Department of Neurology, University of Massachusetts Medical School, Worcester, MA, USA
| | - Evangelos Kiskinis
- The Ken & Ruth Davee Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.,Department of Physiology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - John E Landers
- Department of Neurology, University of Massachusetts Medical School, Worcester, MA, USA
| | - Roy Parker
- Department of Chemistry and Biochemistry, University of Colorado, Boulder, CO, USA.,Howard Hughes Medical Institute, Chevy Chase, MD, USA
| | - Scott A Shaffer
- Department of Biochemistry and Molecular Pharmacology, Worcester, MA, USA.,Mass Spectrometry Facility, University of Massachusetts Medical School, Shrewsbury, MA, USA
| | - Daryl A Bosco
- Department of Neurology, University of Massachusetts Medical School, Worcester, MA, USA.,Department of Biochemistry and Molecular Pharmacology, Worcester, MA, USA
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45
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Tauber D, Tauber G, Khong A, Van Treeck B, Pelletier J, Parker R. Modulation of RNA Condensation by the DEAD-Box Protein eIF4A. Cell 2020; 180:411-426.e16. [PMID: 31928844 DOI: 10.1016/j.cell.2019.12.031] [Citation(s) in RCA: 153] [Impact Index Per Article: 38.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 11/04/2019] [Accepted: 12/20/2019] [Indexed: 01/12/2023]
Abstract
Stress granules are condensates of non-translating mRNAs and proteins involved in the stress response and neurodegenerative diseases. Stress granules form in part through intermolecular RNA-RNA interactions, and to better understand how RNA-based condensation occurs, we demonstrate that RNA is effectively recruited to the surfaces of RNA or RNP condensates in vitro. We demonstrate that, through ATP-dependent RNA binding, the DEAD-box protein eIF4A reduces RNA condensation in vitro and limits stress granule formation in cells. This defines a function for eIF4A to limit intermolecular RNA-RNA interactions in cells. These results establish an important role for eIF4A, and potentially other DEAD-box proteins, as ATP-dependent RNA chaperones that limit the condensation of RNA, analogous to the function of proteins like HSP70 in combatting protein aggregates.
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Affiliation(s)
- Devin Tauber
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO 80309, USA
| | - Gabriel Tauber
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO 80309, USA
| | - Anthony Khong
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO 80309, USA; Howard Hughes Medical Institute, University of Colorado Boulder, Boulder, CO 80309, USA
| | - Briana Van Treeck
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO 80309, USA
| | - Jerry Pelletier
- Department of Biochemistry, McGill University, Montreal, QC H3G 1Y6, Canada; The Rosalind and Morris Goodman Cancer Research Center and the Department of Oncology, McGill University, Montreal, QC, Canada
| | - Roy Parker
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO 80309, USA; Howard Hughes Medical Institute, University of Colorado Boulder, Boulder, CO 80309, USA.
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Chi J, Chen J, Li Y, Huang Z, Wang L, Zhang Y. A Familial Phenotypic and Genetic Study of Mutations in PFN1 Associated with Amyotrophic Lateral Sclerosis. Neurosci Bull 2019; 36:174-178. [PMID: 31802421 DOI: 10.1007/s12264-019-00448-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2019] [Accepted: 07/29/2019] [Indexed: 12/11/2022] Open
Affiliation(s)
- Jieshan Chi
- Department of Neurology, Guangdong Neuroscience Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, 510080, China
| | - Junling Chen
- Department of Neurology, Guangdong Neuroscience Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, 510080, China
| | - Yan Li
- Department of Neurology, Guangdong Neuroscience Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, 510080, China
| | - Zhiheng Huang
- Department of Neurology, Guangdong Neuroscience Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, 510080, China
| | - Lijuan Wang
- Department of Neurology, Guangdong Neuroscience Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, 510080, China
| | - Yuhu Zhang
- Department of Neurology, Guangdong Neuroscience Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, 510080, China.
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Casci I, Krishnamurthy K, Kour S, Tripathy V, Ramesh N, Anderson EN, Marrone L, Grant RA, Oliver S, Gochenaur L, Patel K, Sterneckert J, Gleixner AM, Donnelly CJ, Ruepp MD, Sini AM, Zuccaro E, Pennuto M, Pasinelli P, Pandey UB. Muscleblind acts as a modifier of FUS toxicity by modulating stress granule dynamics and SMN localization. Nat Commun 2019; 10:5583. [PMID: 31811140 PMCID: PMC6898697 DOI: 10.1038/s41467-019-13383-z] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Accepted: 11/05/2019] [Indexed: 12/12/2022] Open
Abstract
Mutations in fused in sarcoma (FUS) lead to amyotrophic lateral sclerosis (ALS) with varying ages of onset, progression and severity. This suggests that unknown genetic factors contribute to disease pathogenesis. Here we show the identification of muscleblind as a novel modifier of FUS-mediated neurodegeneration in vivo. Muscleblind regulates cytoplasmic mislocalization of mutant FUS and subsequent accumulation in stress granules, dendritic morphology and toxicity in mammalian neuronal and human iPSC-derived neurons. Interestingly, genetic modulation of endogenous muscleblind was sufficient to restore survival motor neuron (SMN) protein localization in neurons expressing pathogenic mutations in FUS, suggesting a potential mode of suppression of FUS toxicity. Upregulation of SMN suppressed FUS toxicity in Drosophila and primary cortical neurons, indicating a link between FUS and SMN. Our data provide in vivo evidence that muscleblind is a dominant modifier of FUS-mediated neurodegeneration by regulating FUS-mediated ALS pathogenesis.
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Affiliation(s)
- Ian Casci
- Department of Human Genetics, University of Pittsburgh Graduate School of Public Health, Pittsburgh, PA, USA
- Department of Pediatrics, Children's Hospital of Pittsburgh, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Karthik Krishnamurthy
- Department of Neuroscience, Jefferson Weinberg ALS Center, Vickie and Jack Farber Institute for Neuroscience, Jefferson University, Philadelphia, PA, USA
| | - Sukhleen Kour
- Department of Pediatrics, Children's Hospital of Pittsburgh, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Vadreenath Tripathy
- Center for Regenerative Therapies TU Dresden, Technische Universität Dresden, Fetscherstr. 105, 01307, Dresden, Germany
| | - Nandini Ramesh
- Department of Human Genetics, University of Pittsburgh Graduate School of Public Health, Pittsburgh, PA, USA
- Department of Pediatrics, Children's Hospital of Pittsburgh, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Eric N Anderson
- Department of Pediatrics, Children's Hospital of Pittsburgh, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Lara Marrone
- Center for Regenerative Therapies TU Dresden, Technische Universität Dresden, Fetscherstr. 105, 01307, Dresden, Germany
| | - Rogan A Grant
- Department of Pediatrics, Children's Hospital of Pittsburgh, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Stacie Oliver
- Department of Pediatrics, Children's Hospital of Pittsburgh, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Lauren Gochenaur
- Department of Pediatrics, Children's Hospital of Pittsburgh, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Krishani Patel
- Department of Pediatrics, Children's Hospital of Pittsburgh, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Jared Sterneckert
- Center for Regenerative Therapies TU Dresden, Technische Universität Dresden, Fetscherstr. 105, 01307, Dresden, Germany
| | - Amanda M Gleixner
- Department of Neurobiology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
- Live Like Lou Center for ALS Research, Brain Institute, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Christopher J Donnelly
- Department of Neurobiology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
- Live Like Lou Center for ALS Research, Brain Institute, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Marc-David Ruepp
- UK Dementia Research Institute at King's College London, Institute of Psychiatry, Psychology and Neuroscience, Maurice Wohl Clinical Neuroscience Institute, King's College London, London, SE5 9NU, UK
| | - Antonella M Sini
- Department of Biomedical Sciences (DBS), University of Padova, Padova, Italy
| | - Emanuela Zuccaro
- Department of Biomedical Sciences (DBS), University of Padova, Padova, Italy
- Veneto Institute of Molecular Medicine (VIMM), Padova, Italy
| | - Maria Pennuto
- Department of Biomedical Sciences (DBS), University of Padova, Padova, Italy
- Veneto Institute of Molecular Medicine (VIMM), Padova, Italy
| | - Piera Pasinelli
- Department of Neuroscience, Jefferson Weinberg ALS Center, Vickie and Jack Farber Institute for Neuroscience, Jefferson University, Philadelphia, PA, USA
| | - Udai Bhan Pandey
- Department of Human Genetics, University of Pittsburgh Graduate School of Public Health, Pittsburgh, PA, USA.
- Department of Pediatrics, Children's Hospital of Pittsburgh, University of Pittsburgh Medical Center, Pittsburgh, PA, USA.
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McAlary L, Plotkin SS, Yerbury JJ, Cashman NR. Prion-Like Propagation of Protein Misfolding and Aggregation in Amyotrophic Lateral Sclerosis. Front Mol Neurosci 2019; 12:262. [PMID: 31736708 PMCID: PMC6838634 DOI: 10.3389/fnmol.2019.00262] [Citation(s) in RCA: 83] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Accepted: 10/14/2019] [Indexed: 01/26/2023] Open
Abstract
The discovery that prion protein can misfold into a pathological conformation that encodes structural information capable of both propagation and inducing severe neuropathology has revolutionized our understanding of neurodegenerative disease. Many neurodegenerative diseases with a protein misfolding component are now classified as “prion-like” owing to the propagation of both symptoms and protein aggregation pathology in affected individuals. The neuromuscular disorder amyotrophic lateral sclerosis (ALS) is characterized by protein inclusions formed by either TAR DNA-binding protein of 43 kDa (TDP-43), Cu/Zn superoxide dismutase (SOD1), or fused in sarcoma (FUS), in both upper and lower motor neurons. Evidence from in vitro, cell culture, and in vivo studies has provided strong evidence to support the involvement of a prion-like mechanism in ALS. In this article, we review the evidence suggesting that prion-like propagation of protein aggregation is a primary pathomechanism in ALS, focusing on the key proteins and genes involved in disease (TDP-43, SOD1, FUS, and C9orf72). In each case, we discuss the evidence ranging from biophysical studies to in vivo examinations of prion-like spreading. We suggest that the idiopathic nature of ALS may stem from its prion-like nature and that elucidation of the specific propagating protein assemblies is paramount to developing effective therapies.
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Affiliation(s)
- Luke McAlary
- Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW, Australia.,Molecular Horizons and School of Chemistry and Molecular Bioscience, Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, NSW, Australia
| | - Steven S Plotkin
- Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, Canada.,Genome Sciences and Technology Program, University of British Columbia, Vancouver, BC, Canada
| | - Justin J Yerbury
- Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW, Australia.,Molecular Horizons and School of Chemistry and Molecular Bioscience, Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, NSW, Australia
| | - Neil R Cashman
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada
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Abstract
Recent advances suggest that the response of RNA metabolism to stress has an important role in the pathophysiology of neurodegenerative diseases, particularly amyotrophic lateral sclerosis, frontotemporal dementias and Alzheimer disease. RNA-binding proteins (RBPs) control the utilization of mRNA during stress, in part through the formation of membraneless organelles termed stress granules (SGs). These structures form through a process of liquid-liquid phase separation. Multiple biochemical pathways regulate SG biology. The major signalling pathways regulating SG formation include the mammalian target of rapamycin (mTOR)-eukaryotic translation initiation factor 4F (eIF4F) and eIF2α pathways, whereas the pathways regulating SG dispersion and removal are mediated by valosin-containing protein and the autolysosomal cascade. Post-translational modifications of RBPs also strongly contribute to the regulation of SGs. Evidence indicates that SGs are supposed to be transient structures, but the chronic stresses associated with ageing lead to chronic, persistent SGs that appear to act as a nidus for the aggregation of disease-related proteins. We suggest a model describing how intrinsic vulnerabilities within the cellular RNA metabolism might lead to the pathological aggregation of RBPs when SGs become persistent. This process might accelerate the pathophysiology of many neurodegenerative diseases and myopathies, and it suggests new targets for disease intervention.
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Affiliation(s)
- Benjamin Wolozin
- Department of Pharmacology, Boston University School of Medicine, Boston, MA, USA.
- Department of Neurology, Boston University School of Medicine, Boston, MA, USA.
| | - Pavel Ivanov
- Division of Rheumatology, Immunology and Allergy, Brigham and Women's Hospital, Boston, MA, USA
- Department of Medicine, Harvard Medical School, Boston, MA, USA
- The Broad Institute of Harvard and MIT, Cambridge, MA, USA
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Ryan VH, Fawzi NL. Physiological, Pathological, and Targetable Membraneless Organelles in Neurons. Trends Neurosci 2019; 42:693-708. [PMID: 31493925 PMCID: PMC6779520 DOI: 10.1016/j.tins.2019.08.005] [Citation(s) in RCA: 72] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2019] [Revised: 07/03/2019] [Accepted: 08/05/2019] [Indexed: 12/20/2022]
Abstract
Neurons require unique subcellular compartmentalization to function efficiently. Formed from proteins and RNAs through liquid-liquid phase separation, membraneless organelles (MLOs) have emerged as one way in which cells form distinct, specialized compartments in the absence of lipid membranes. We first discuss MLOs that are common to many cell types as well as those that are specific to neurons. Interestingly, many proteins associated with neurodegenerative disease are found in MLOs, particularly in stress and transport granules. We next review possible links between neurodegeneration and MLOs, and the hypothesis that the protein and RNA inclusions formed in disease are related to the functional complexes occurring inside these MLOs. Finally, we discuss the hypothesis that protein post-translational modifications (PTMs), which can alter phase separation, can modulate MLO formation and provide potential new therapeutic strategies for currently untreatable neurodegenerative diseases.
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Affiliation(s)
- Veronica H Ryan
- Neuroscience Graduate Program, Brown University, Providence, RI 02912, USA
| | - Nicolas L Fawzi
- Department of Molecular Pharmacology, Physiology, and Biotechnology, Brown University, Providence, RI 02912, USA.
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