1
|
Wang L, Li P. Arginine methylation-enabled FUS phase separation with SMN contributes to neuronal granule formation. Cell Rep 2024; 43:114537. [PMID: 39052476 DOI: 10.1016/j.celrep.2024.114537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Revised: 05/03/2024] [Accepted: 07/09/2024] [Indexed: 07/27/2024] Open
Abstract
Various ribonucleoprotein complexes (RNPs) often function in the form of membraneless organelles derived from multivalence-driven liquid-liquid phase separation (LLPS). Post-translational modifications, such as phosphorylation and arginine methylation, govern the assembly and disassembly of membraneless organelles. This study reveals that asymmetric dimethylation of arginine can create extra binding sites for multivalent Tudor domain-containing proteins like survival of motor neuron (SMN) protein, thereby lowering the threshold for LLPS of RNPs, such as fused in sarcoma (FUS). Accordingly, FUS hypomethylation or knockdown of SMN disrupts the formation and transport of neuronal granules in axons. Wild-type SMN, but not the spinal muscular atrophy-associated form of SMN, SMN-Δ7, rescues neuronal defects due to SMN knockdown. Importantly, a fusion of SMN-Δ7 to an exogenous oligomeric protein is sufficient to rescue axon length defects caused by SMN knockdown. Our findings highlight the significant role of arginine methylation-enabled multivalent interactions in LLPS and suggest their potential impact on various aspects of neuronal activities in neurodegenerative diseases.
Collapse
Affiliation(s)
- Lingyao Wang
- State Key Laboratory of Membrane Biology, Beijing Frontier Research Center for Biological Structure, School of Life Sciences, Tsinghua University; Tsinghua-Peking Center for Life Sciences, Beijing 100084, China
| | - Pilong Li
- State Key Laboratory of Membrane Biology, Beijing Frontier Research Center for Biological Structure, School of Life Sciences, Tsinghua University; Tsinghua-Peking Center for Life Sciences, Beijing 100084, China.
| |
Collapse
|
2
|
Staderini T, Bigi A, Lagrève C, Marzi I, Bemporad F, Chiti F. Biophysical characterization of the phase separation of TDP-43 devoid of the C-terminal domain. Cell Mol Biol Lett 2024; 29:104. [PMID: 38997630 PMCID: PMC11245819 DOI: 10.1186/s11658-024-00615-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Accepted: 06/25/2024] [Indexed: 07/14/2024] Open
Abstract
BACKGROUND Frontotemporal lobar degeneration with ubiquitin-positive inclusions (FTLD-TDP), amyotrophic lateral sclerosis (ALS) and limbic-predominant age-related TDP-43 encephalopathy (LATE) are associated with deposition of cytoplasmic inclusions of TAR DNA-binding protein 43 (TDP-43) in neurons. One complexity of this process lies in the ability of TDP-43 to form liquid-phase membraneless organelles in cells. Previous work has shown that the recombinant, purified, prion-like domain (PrLD) forms liquid droplets in vitro, but the behaviour of the complementary fragment is uncertain. METHODS We have purified such a construct without the PrLD (PrLD-less TDP-43) and have induced its phase separation using a solution-jump method and an array of biophysical techniques to study the morphology, state of matter and structure of the TDP-43 assemblies. RESULTS The fluorescent TMR-labelled protein construct, imaged using confocal fluorescence, formed rapidly (< 1 min) round, homogeneous and 0.5-1.0 µm wide assemblies which then coalesced into larger, yet round, species. When labelled with AlexaFluor488, they initially exhibited fluorescence recovery after photobleaching (FRAP), showing a liquid behaviour distinct from full-length TDP-43 and similar to PrLD. The protein molecules did not undergo major structural changes, as determined with circular dichroism and intrinsic fluorescence spectroscopies. This process had a pH and salt dependence distinct from those of full-length TDP-43 and its PrLD, which can be rationalized on the grounds of electrostatic forces. CONCLUSIONS Similarly to PrLD, PrLD-less TDP-43 forms liquid droplets in vitro through liquid-liquid phase separation (LLPS), unlike the full-length protein that rather undergoes liquid-solid phase separation (LSPS). These results offer a rationale of the complex electrostatic forces governing phase separation of full-length TDP-43 and its fragments. On the one hand, PrLD-less TDP-43 has a low pI and oppositively charged domains, and LLPS is inhibited by salts, which attenuate inter-domain electrostatic attractions. On the other hand, PrLD is positively charged due to a high isoionic point (pI) and LLPS is therefore promoted by salts and pH increases as they both reduce electrostatic repulsions. By contrast, full-length TDP-43 undergoes LSPS most favourably at its pI, with positive and negative salt dependences at lower and higher pH, respectively, depending on whether repulsive or attractive forces dominate, respectively.
Collapse
Affiliation(s)
- Tommaso Staderini
- Department of Experimental and Clinical Biomedical Sciences "Mario Serio", University of Florence, 50134, Florence, Italy
- Department of Chemistry "Ugo Schiff", University of Florence, 50019, Florence, Italy
- Magnetic Resonance Center (CERM), University of Florence, Sesto Fiorentino, 50019, Florence, Italy
| | - Alessandra Bigi
- Department of Experimental and Clinical Biomedical Sciences "Mario Serio", University of Florence, 50134, Florence, Italy
| | - Clément Lagrève
- Department of Experimental and Clinical Biomedical Sciences "Mario Serio", University of Florence, 50134, Florence, Italy
- Chimie ParisTech-PSL, École Nationale Supérieur de Chimie de Paris, 11 rue Pierre et Marie Curie, 75231, Paris, France
| | - Isabella Marzi
- Department of Experimental and Clinical Biomedical Sciences "Mario Serio", University of Florence, 50134, Florence, Italy
| | - Francesco Bemporad
- Department of Experimental and Clinical Biomedical Sciences "Mario Serio", University of Florence, 50134, Florence, Italy
| | - Fabrizio Chiti
- Department of Experimental and Clinical Biomedical Sciences "Mario Serio", University of Florence, 50134, Florence, Italy.
| |
Collapse
|
3
|
Dykstra MM, Weskamp K, Gómez NB, Waksmacki J, Tank E, Glineburg MR, Snyder A, Pinarbasi E, Bekier M, Li X, Bai J, Shahzad S, Nedumaran J, Wieland C, Stewart C, Willey S, Grotewold N, McBride J, Moran JJ, Suryakumar AV, Lucas M, Tessier P, Ward M, Todd P, Barmada SJ. TDP43 autoregulation gives rise to shortened isoforms that are tightly controlled by both transcriptional and post-translational mechanisms. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.02.601776. [PMID: 39005384 PMCID: PMC11244999 DOI: 10.1101/2024.07.02.601776] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/16/2024]
Abstract
The nuclear RNA-binding protein TDP43 is integrally involved in the pathogenesis of amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD). Previous studies uncovered N-terminal TDP43 isoforms that are predominantly cytosolic in localization, highly prone to aggregation, and enriched in susceptible spinal motor neurons. In healthy cells, however, these shortened (s)TDP43 isoforms are difficult to detect in comparison to full-length (fl)TDP43, raising questions regarding their origin and selective regulation. Here, we show that sTDP43 is created as a byproduct of TDP43 autoregulation and cleared by nonsense mediated RNA decay (NMD). The sTDP43-encoding transcripts that escape NMD can lead to toxicity but are rapidly degraded post-translationally. Circumventing these regulatory mechanisms by overexpressing sTDP43 results in neurodegeneration in vitro and in vivo via N-terminal oligomerization and impairment of flTDP43 splicing activity, in addition to RNA binding-dependent gain-of-function toxicity. Collectively, these studies highlight endogenous mechanisms that tightly regulate sTDP43 expression and provide insight into the consequences of aberrant sTDP43 accumulation in disease.
Collapse
Affiliation(s)
- Megan M. Dykstra
- Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI
| | - Kaitlin Weskamp
- Chemistry Department, Nebraska Wesleyan University, Lincoln, NE
| | - Nicolás B. Gómez
- Graduate Program in Cell and Molecular Biology, University of Michigan, Ann Arbor, MI
- Medical Scientist Training Program, University of Michigan, Ann Arbor, MI
| | - Jacob Waksmacki
- Department of Neurology, University of Michigan, Ann Arbor, MI
| | - Elizabeth Tank
- Department of Neurology, University of Michigan, Ann Arbor, MI
| | - M. Rebecca Glineburg
- Biological Sciences, Schmid College of Science and Technology, Chapman University, Orange, CA
| | | | - Emile Pinarbasi
- Department of Neurology, University of Michigan, Ann Arbor, MI
- Neuropathology, Department of Pathology, Michigan Medicine, University of Michigan, Ann Arbor, MI
| | - Michael Bekier
- Department of Neurology, University of Michigan, Ann Arbor, MI
| | - Xingli Li
- Department of Neurology, University of Michigan, Ann Arbor, MI
| | - Jen Bai
- Department of Neurology, University of Michigan, Ann Arbor, MI
| | | | - Juno Nedumaran
- Department of Neurology, University of Michigan, Ann Arbor, MI
| | - Clare Wieland
- Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI
- Medical Scientist Training Program, University of Michigan, Ann Arbor, MI
| | - Corey Stewart
- Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI
| | - Sydney Willey
- Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI
| | - Nikolas Grotewold
- Medical Scientist Training Program, University of Michigan, Ann Arbor, MI
| | - Jonathon McBride
- Department of Anesthesiology, University of Michigan, Ann Arbor, MI
| | - John J. Moran
- Atlanta Pediatric Research Alliance, Emory University, Atlanta, GA
| | | | - Michael Lucas
- Department of Chemical Engineering, University of Michigan, Ann Arbor, MI
| | - Peter Tessier
- Department of Chemical Engineering, University of Michigan, Ann Arbor, MI
| | | | - Peter Todd
- Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI
- Graduate Program in Cell and Molecular Biology, University of Michigan, Ann Arbor, MI
- Medical Scientist Training Program, University of Michigan, Ann Arbor, MI
- Department of Neurology, University of Michigan, Ann Arbor, MI
- Veterans Affairs Medical Center, Ann Arbor, MI
| | - Sami J. Barmada
- Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI
- Graduate Program in Cell and Molecular Biology, University of Michigan, Ann Arbor, MI
- Medical Scientist Training Program, University of Michigan, Ann Arbor, MI
- Department of Neurology, University of Michigan, Ann Arbor, MI
| |
Collapse
|
4
|
Wen X, Xu H, Woolley PR, Conway OM, Yao J, Matouschek A, Lambowitz AM, Paull TT. Senataxin deficiency disrupts proteostasis through nucleolar ncRNA-driven protein aggregation. J Cell Biol 2024; 223:e202309036. [PMID: 38717338 PMCID: PMC11080644 DOI: 10.1083/jcb.202309036] [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: 09/06/2023] [Revised: 01/19/2024] [Accepted: 03/13/2024] [Indexed: 05/12/2024] Open
Abstract
Senataxin is an evolutionarily conserved RNA-DNA helicase involved in DNA repair and transcription termination that is associated with human neurodegenerative disorders. Here, we investigated whether Senataxin loss affects protein homeostasis based on previous work showing R-loop-driven accumulation of DNA damage and protein aggregates in human cells. We find that Senataxin loss results in the accumulation of insoluble proteins, including many factors known to be prone to aggregation in neurodegenerative disorders. These aggregates are located primarily in the nucleolus and are promoted by upregulation of non-coding RNAs expressed from the intergenic spacer region of ribosomal DNA. We also map sites of R-loop accumulation in human cells lacking Senataxin and find higher RNA-DNA hybrids within the ribosomal DNA, peri-centromeric regions, and other intergenic sites but not at annotated protein-coding genes. These findings indicate that Senataxin loss affects the solubility of the proteome through the regulation of transcription-dependent lesions in the nucleus and the nucleolus.
Collapse
Affiliation(s)
- Xuemei Wen
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, USA
| | - Hengyi Xu
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, USA
| | - Phillip R. Woolley
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, USA
| | - Olivia M. Conway
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, USA
| | - Jun Yao
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, USA
| | - Andreas Matouschek
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, USA
| | - Alan M. Lambowitz
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, USA
- Department of Oncology, Dell Medical School, The University of Texas at Austin, Austin, TX, USA
| | - Tanya T. Paull
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, USA
- Department of Oncology, Dell Medical School, The University of Texas at Austin, Austin, TX, USA
| |
Collapse
|
5
|
Guo Q, Ping L, Dammer EB, Yin L, Xu K, Shantaraman A, Fox EJ, Golde TE, Johnson ECB, Roberts BR, Lah JJ, Levey AI, Seyfried NT. Heparin-enriched plasma proteome is significantly altered in Alzheimer's Disease. RESEARCH SQUARE 2024:rs.3.rs-3933136. [PMID: 38464223 PMCID: PMC10925398 DOI: 10.21203/rs.3.rs-3933136/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/12/2024]
Abstract
Introduction Heparin binding proteins (HBPs) with roles in extracellular matrix assembly are strongly correlated to β-amyloid (Aβ) and tau pathology in Alzheimer's disease (AD) brain and cerebrospinal fluid (CSF). However, it remains challenging to detect these proteins in plasma using standard mass spectrometry-based proteomic approaches. Methods We employed heparin affinity chromatography, followed by off-line fractionation and tandem mass tag mass spectrometry (TMT-MS), to capture and enrich HBPs in plasma obtained from AD (n=62) and control (n=47) samples. These profiles were then correlated to a consensus AD brain proteome, as well as with Aβ, tau and phosphorylated tau (pTau) CSF biomarkers from the same individuals. We then leveraged published human postmortem brain proteome datasets to assess the overlap with the heparin-enriched plasma proteome. Results Heparin-enrichment from plasma was highly reproducible, enriched well-known HBPs like APOE and thrombin, and depleted high-abundance proteins such as albumin. A total of 2865 proteins, spanning 10 orders of magnitude were detectable. Utilizing a consensus AD brain protein co-expression network, we observed that specific plasma HBPs exhibited consistent direction of change in both brain and plasma, whereas others displayed divergent changes highlighting the complex interplay between the two compartments. Elevated HBPs in AD plasma, when compared to controls, included members of the matrisome module in brain that accumulate within Aβ deposits, such as SMOC1, SMOC2, SPON1, MDK, OLFML3, FRZB, GPNMB, and APOE. Additionally, heparin enriched plasma proteins demonstrated significant correlations with conventional AD CSF biomarkers, including Aβ, total tau, pTau, and plasma pTau from the same individuals. Conclusion These findings support the utility of a heparin-affinity approach for enriching amyloid-associated proteins, as well as a wide spectrum of plasma biomarkers that reflect pathological changes in the AD brain.
Collapse
Affiliation(s)
- Qi Guo
- Emory University School of Medicine
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
6
|
García Morato J, Gloeckner CJ, Kahle PJ. Proteomics elucidating physiological and pathological functions of TDP-43. Proteomics 2023; 23:e2200410. [PMID: 37671599 DOI: 10.1002/pmic.202200410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 08/02/2023] [Accepted: 08/10/2023] [Indexed: 09/07/2023]
Abstract
Trans-activation response DNA binding protein of 43 kDa (TDP-43) regulates a great variety of cellular processes in the nucleus and cytosol. In addition, a defined subset of neurodegenerative diseases is characterized by nuclear depletion of TDP-43 as well as cytosolic mislocalization and aggregation. To perform its diverse functions TDP-43 can associate with different ribonucleoprotein complexes. Combined with transcriptomics, MS interactome studies have unveiled associations between TDP-43 and the spliceosome machinery, polysomes and RNA granules. Moreover, the highly dynamic, low-valency interactions regulated by its low-complexity domain calls for innovative proximity labeling methodologies. In addition to protein partners, the analysis of post-translational modifications showed that they may play a role in the nucleocytoplasmic shuttling, RNA binding, liquid-liquid phase separation and protein aggregation of TDP-43. Here we review the various TDP-43 ribonucleoprotein complexes characterized so far, how they contribute to the diverse functions of TDP-43, and roles of post-translational modifications. Further understanding of the fluid dynamic properties of TDP-43 in ribonucleoprotein complexes, RNA granules, and self-assemblies will advance the understanding of RNA processing in cells and perhaps help to develop novel therapeutic approaches for TDPopathies.
Collapse
Affiliation(s)
- Jorge García Morato
- Laboratory of Functional Neurogenetics, Department of Neurodegeneration, German Center of Neurodegenerative Diseases and Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
| | - Christian Johannes Gloeckner
- Research Group Functional Neuroproteomics, German Center of Neurodegenerative Diseases, Tübingen, Germany
- Core Facility for Medical Bioanalytics, Institute for Ophthalmic Research, Center for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Philipp J Kahle
- Laboratory of Functional Neurogenetics, Department of Neurodegeneration, German Center of Neurodegenerative Diseases and Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
- Department of Biochemistry, University of Tübingen, Tübingen, Germany
| |
Collapse
|
7
|
Evangelista BA, Cahalan SR, Ragusa JV, Mordant A, Necarsulmer JC, Perna RJ, Ajit T, White K, Barker NK, Tian X, Cohen S, Meeker R, Herring LE, Cohen TJ. Tandem detergent-extraction and immunoprecipitation of proteinopathy: Scalable enrichment of ALS-associated TDP-43 aggregates. iScience 2023; 26:106645. [PMID: 37182104 PMCID: PMC10173608 DOI: 10.1016/j.isci.2023.106645] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Revised: 01/03/2023] [Accepted: 04/05/2023] [Indexed: 05/16/2023] Open
Abstract
Transactive response DNA-binding protein of 43 kDa (TDP-43) is a highly conserved, ubiquitously expressed nucleic acid-binding protein that regulates DNA/RNA metabolism. Genetics and neuropathology studies have linked TDP-43 to several neuromuscular and neurological disorders including amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD). Under pathological conditions, TDP-43 mislocalizes to the cytoplasm where it forms insoluble, hyper-phosphorylated aggregates during disease progression. Here, we optimized a scalable in vitro immuno-purification strategy referred to as tandem detergent-extraction and immunoprecipitation of proteinopathy (TDiP) to isolate TDP-43 aggregates that recapitulate those identified in postmortem ALS tissue. Moreover, we demonstrate that these purified aggregates can be utilized in biochemical, proteomics, and live-cell assays. This platform offers a rapid, accessible, and streamlined approach to study ALS disease mechanisms, while overcoming many limitations that have hampered TDP-43 disease modeling and therapeutic drug discovery efforts.
Collapse
Affiliation(s)
- Baggio A. Evangelista
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Shannon R. Cahalan
- Medical Student Training in Aging Research, Center for Aging and Health, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Joey V. Ragusa
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Angie Mordant
- Proteomics Core Facility, Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Julie C. Necarsulmer
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Robert J. Perna
- Department of Neurology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Tejazaditya Ajit
- Department of Neurology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Kristen White
- Microscopy Services Laboratory, Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Natalie K. Barker
- Proteomics Core Facility, Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Xu Tian
- Department of Neurology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Sarah Cohen
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Rick Meeker
- Department of Neurology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Laura E. Herring
- Proteomics Core Facility, Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Todd J. Cohen
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Department of Neurology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- UNC Neuroscience Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| |
Collapse
|
8
|
Wijegunawardana D, Vishal SS, Venkatesh N, Gopal PP. Ataxin-2 polyglutamine expansions aberrantly sequester TDP-43, drive ribonucleoprotein condensate transport dysfunction and suppress local translation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.30.526372. [PMID: 36778347 PMCID: PMC9915502 DOI: 10.1101/2023.01.30.526372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Altered RNA metabolism is a common pathogenic mechanism linked to familial and sporadic Amyotrophic lateral sclerosis (ALS). ALS is characterized by mislocalization and aggregation of TDP-43, an RNA-binding protein (RBP) with multiple roles in post-transcriptional RNA processing. Recent studies have identified genetic interactions between TDP-43 and Ataxin-2, a polyglutamine (polyQ) RBP in which intermediate length polyQ expansions confer increased ALS risk. Here, we used live-cell confocal imaging, photobleaching and translation reporter assays to study the localization, transport dynamics and mRNA regulatory functions of TDP-43/Ataxin-2 in rodent primary cortical neurons. We show that Ataxin-2 polyQ expansions aberrantly sequester TDP-43 within ribonucleoprotein (RNP) condensates, and disrupt both its motility along the axon and liquid-like properties. Our data suggest that Ataxin-2 governs motility and translation of neuronal RNP condensates and that Ataxin-2 polyQ expansions fundamentally perturb spatial localization of mRNA and suppress local translation. Overall, these results indicate Ataxin-2 polyQ expansions have detrimental effects on stability, localization, and translation of transcripts critical for axonal and cytoskeletal integrity, particularly important for motor neurons.
Collapse
|
9
|
Huntingtin and Other Neurodegeneration-Associated Proteins in the Development of Intracellular Pathologies: Potential Target Search for Therapeutic Intervention. Int J Mol Sci 2022; 23:ijms232415533. [PMID: 36555175 PMCID: PMC9779313 DOI: 10.3390/ijms232415533] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Revised: 12/02/2022] [Accepted: 12/05/2022] [Indexed: 12/13/2022] Open
Abstract
Neurodegenerative diseases are currently incurable. Numerous experimental data accumulated over the past fifty years have brought us closer to understanding the molecular and cell mechanisms responsible for their development. However, these data are not enough for a complete understanding of the genesis of these diseases, nor to suggest treatment methods. It turns out that many cellular pathologies developing during neurodegeneration coincide from disease to disease. These observations give hope to finding a common intracellular target(s) and to offering a universal method of treatment. In this review, we attempt to analyze data on similar cellular disorders among neurodegenerative diseases in general, and polyglutamine neurodegenerative diseases in particular, focusing on the interaction of various proteins involved in the development of neurodegenerative diseases with various cellular organelles. The main purposes of this review are: (1) to outline the spectrum of common intracellular pathologies and to answer the question of whether it is possible to find potential universal target(s) for therapeutic intervention; (2) to identify specific intracellular pathologies and to speculate about a possible general approach for their treatment.
Collapse
|
10
|
Dhakal S, Robang AS, Bhatt N, Puangmalai N, Fung L, Kayed R, Paravastu AK, Rangachari V. Distinct neurotoxic TDP-43 fibril polymorphs are generated by heterotypic interactions with α-Synuclein. J Biol Chem 2022; 298:102498. [PMID: 36116552 PMCID: PMC9587012 DOI: 10.1016/j.jbc.2022.102498] [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: 06/29/2022] [Revised: 09/08/2022] [Accepted: 09/13/2022] [Indexed: 11/17/2022] Open
Abstract
Amyloid aggregates of specific proteins constitute important pathological hallmarks in many neurodegenerative diseases, defining neuronal degeneration and disease onset. Recently, increasing numbers of patients show comorbidities and overlaps between multiple neurodegenerative diseases, presenting distinct phenotypes. Such overlaps are often accompanied by colocalizations of more than one amyloid protein, prompting the question of whether direct interactions between different amyloid proteins could generate heterotypic amyloids. To answer this question, we investigated the effect of α-synuclein (αS) on the DNA-binding protein TDP-43 aggregation inspired by their coexistence in pathologies such as Lewy body dementia and limbic predominant age-related TDP-43 encephalopathy. We previously showed αS and prion-like C-terminal domain (PrLD) of TDP-43 synergistically interact to generate toxic heterotypic aggregates. Here, we extend these studies to investigate whether αS induces structurally and functionally distinct polymorphs of PrLD aggregates. Using αS-PrLD heterotypic aggregates generated in two different stoichiometric proportions, we show αS can affect PrLD fibril forms. PrLD fibrils show distinctive residue level signatures determined by solid state NMR, dye-binding capability, proteinase K (PK) stability, and thermal stability toward SDS denaturation. Furthremore, by gold nanoparticle labeling and transmission electron microscopy, we show the presence of both αS and PrLD proteins within the same fibrils, confirming the existence of heterotypic amyloid fibrils. We also observe αS and PrLD colocalize in the cytosol of neuroblastoma cells and show that the heterotypic PrLD fibrils selectively induce synaptic dysfunction in primary neurons. These findings establish the existence of heterotypic amyloid and provide a molecular basis for the observed overlap between synucleinopathies and TDP-43 proteinopathies.
Collapse
Affiliation(s)
- Shailendra Dhakal
- Department of Chemistry and Biochemistry, School of Mathematics and Natural Sciences, University of Southern Mississippi, Hattiesburg, Mississippi, USA; Center for Molecular and Cellular Biosciences, University of Southern Mississippi, Hattiesburg, Mississippi, USA
| | - Alicia S Robang
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Nemil Bhatt
- Mitchell Center for Neurodegenerative Disorders, University of Texas Medical Branch, Galveston, Texas, USA
| | - Nicha Puangmalai
- Mitchell Center for Neurodegenerative Disorders, University of Texas Medical Branch, Galveston, Texas, USA
| | - Leiana Fung
- Mitchell Center for Neurodegenerative Disorders, University of Texas Medical Branch, Galveston, Texas, USA
| | - Rakez Kayed
- Mitchell Center for Neurodegenerative Disorders, University of Texas Medical Branch, Galveston, Texas, USA
| | - Anant K Paravastu
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia, USA.
| | - Vijayaraghavan Rangachari
- Department of Chemistry and Biochemistry, School of Mathematics and Natural Sciences, University of Southern Mississippi, Hattiesburg, Mississippi, USA; Center for Molecular and Cellular Biosciences, University of Southern Mississippi, Hattiesburg, Mississippi, USA.
| |
Collapse
|
11
|
Tran NN, Lee BH. Functional implication of ubiquitinating and deubiquitinating mechanisms in TDP-43 proteinopathies. Front Cell Dev Biol 2022; 10:931968. [PMID: 36158183 PMCID: PMC9500471 DOI: 10.3389/fcell.2022.931968] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 08/23/2022] [Indexed: 11/15/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease in which motor neurons in spinal cord and motor cortex are progressively lost. About 15% cases of ALS also develop the frontotemporal dementia (FTD), in which the frontotemporal lobar degeneration (FTLD) occurs in the frontal and temporal lobes of the brain. Among the pathologic commonalities in ALS and FTD is ubiquitin-positive cytoplasmic aggregation of TDP-43 that may reflect both its loss-of-function and gain-of-toxicity from proteostasis impairment. Deep understanding of how protein quality control mechanisms regulate TDP-43 proteinopathies still remains elusive. Recently, a growing body of evidence indicates that ubiquitinating and deubiquitinating pathways are critically engaged in the fate decision of aberrant or pathological TDP-43 proteins. E3 ubiquitin ligases coupled with deubiquitinating enzymes may influence the TDP-43-associated proteotoxicity through diverse events, such as protein stability, translocation, and stress granule or inclusion formation. In this article, we recapitulate our current understanding of how ubiquitinating and deubiquitinating mechanisms can modulate TDP-43 protein quality and its pathogenic nature, thus shedding light on developing targeted therapies for ALS and FTD by harnessing protein degradation machinery.
Collapse
Affiliation(s)
- Non-Nuoc Tran
- Department of New Biology, Daegu-Gyeongbuk Institute of Science and Technology (DGIST), Daegu, South Korea
| | - Byung-Hoon Lee
- Department of New Biology, Daegu-Gyeongbuk Institute of Science and Technology (DGIST), Daegu, South Korea
- Department of New Biology Research Center (NBRC), Daegu-Gyeongbuk Institute of Science and Technology (DGIST), Daegu, South Korea
- *Correspondence: Byung-Hoon Lee,
| |
Collapse
|
12
|
Krause LJ, Herrera MG, Winklhofer KF. The Role of Ubiquitin in Regulating Stress Granule Dynamics. Front Physiol 2022; 13:910759. [PMID: 35694405 PMCID: PMC9174786 DOI: 10.3389/fphys.2022.910759] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Accepted: 05/09/2022] [Indexed: 11/30/2022] Open
Abstract
Stress granules (SGs) are dynamic, reversible biomolecular condensates, which assemble in the cytoplasm of eukaryotic cells under various stress conditions. Formation of SGs typically occurs upon stress-induced translational arrest and polysome disassembly. The increase in cytoplasmic mRNAs triggers the formation of a protein-RNA network that undergoes liquid-liquid phase separation when a critical interaction threshold has been reached. This adaptive stress response allows a transient shutdown of several cellular processes until the stress is removed. During the recovery from stress, SGs disassemble to re-establish cellular activities. Persistent stress and disease-related mutations in SG components favor the formation of aberrant SGs that are impaired in disassembly and prone to aggregation. Recently, posttranslational modifications of SG components have been identified as major regulators of SG dynamics. Here, we summarize new insights into the role of ubiquitination in affecting SG dynamics and clearance and discuss implications for neurodegenerative diseases linked to aberrant SG formation.
Collapse
Affiliation(s)
- Laura J. Krause
- Department of Molecular Cell Biology, Institute of Biochemistry and Pathobiochemistry, Ruhr University Bochum, Bochum, Germany
- RESOLV Cluster of Excellence, Ruhr University Bochum, Bochum, Germany
| | - Maria G. Herrera
- Department of Molecular Cell Biology, Institute of Biochemistry and Pathobiochemistry, Ruhr University Bochum, Bochum, Germany
| | - Konstanze F. Winklhofer
- Department of Molecular Cell Biology, Institute of Biochemistry and Pathobiochemistry, Ruhr University Bochum, Bochum, Germany
- RESOLV Cluster of Excellence, Ruhr University Bochum, Bochum, Germany
| |
Collapse
|
13
|
Huiting W, Dekker SL, van der Lienden JCJ, Mergener R, Musskopf MK, Furtado GV, Gerrits E, Coit D, Oghbaie M, Di Stefano LH, Schepers H, van Waarde-Verhagen MAWH, Couzijn S, Barazzuol L, LaCava J, Kampinga HH, Bergink S. Targeting DNA topoisomerases or checkpoint kinases results in an overload of chaperone systems, triggering aggregation of a metastable subproteome. eLife 2022; 11:70726. [PMID: 35200138 PMCID: PMC8871389 DOI: 10.7554/elife.70726] [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: 05/27/2021] [Accepted: 01/07/2022] [Indexed: 02/07/2023] Open
Abstract
A loss of the checkpoint kinase ataxia telangiectasia mutated (ATM) leads to impairments in the DNA damage response, and in humans causes cerebellar neurodegeneration, and an increased risk of cancer. A loss of ATM is also associated with increased protein aggregation. The relevance and characteristics of this aggregation are still incompletely understood. Moreover, it is unclear to what extent other genotoxic conditions can trigger protein aggregation as well. Here, we show that targeting ATM, but also ATR or DNA topoisomerases, results in the widespread aggregation of a metastable, disease-associated subfraction of the proteome. Aggregation-prone model substrates, including Huntingtin exon 1 containing an expanded polyglutamine repeat, aggregate faster under these conditions. This increased aggregation results from an overload of chaperone systems, which lowers the cell-intrinsic threshold for proteins to aggregate. In line with this, we find that inhibition of the HSP70 chaperone system further exacerbates the increased protein aggregation. Moreover, we identify the molecular chaperone HSPB5 as a cell-specific suppressor of it. Our findings reveal that various genotoxic conditions trigger widespread protein aggregation in a manner that is highly reminiscent of the aggregation occurring in situations of proteotoxic stress and in proteinopathies. Cells are constantly perceiving and responding to changes in their surroundings, and challenging conditions such as extreme heat or toxic chemicals can put cells under stress. When this happens, protein production can be affected. Proteins are long chains of chemical building blocks called amino acids, and they can only perform their roles if they fold into the right shape. Some proteins fold easily and remain folded, but others can be unstable and often become misfolded. Unfolded proteins can become a problem because they stick to each other, forming large clumps called aggregates that can interfere with the normal activity of cells, causing damage. The causes of stress that have a direct effect on protein folding are called proteotoxic stresses, and include, for example, high temperatures, which make proteins more flexible and unstable, increasing their chances of becoming unfolded. To prevent proteins becoming misfolded, cells can make ‘protein chaperones’, a type of proteins that help other proteins fold correctly and stay folded. The production of protein chaperones often increases in response to proteotoxic stress. However, there are other types of stress too, such as genotoxic stress, which damages DNA. It is unclear what effect genotoxic stress has on protein folding. Huiting et al. studied protein folding during genotoxic stress in human cells grown in the lab. Stress was induced by either blocking the proteins that repair DNA or by ‘trapping’ the proteins that release DNA tension, both of which result in DNA damage. The analysis showed that, similar to the effects of proteotoxic stress, genotoxic stress increased the number of proteins that aggregate, although certain proteins formed aggregates even without stress, particularly if they were common and relatively unstable proteins. Huiting et al.’s results suggest that aggregation increases in cells under genotoxic stress because the cells fail to produce enough chaperones to effectively fold all the proteins that need it. Indeed, Huiting et al. showed that aggregates contain many proteins that rely on chaperones, and that increasing the number of chaperones in stressed cells reduced protein aggregation. This work shows that genotoxic stress can affect protein folding by limiting the availability of chaperones, which increases protein aggregation. Remarkably, there is a substantial overlap between proteins that aggregate in diseases that affect the brain – such as Alzheimer’s disease – and proteins that aggregate after genotoxic stress. Therefore, further research could focus on determining whether genotoxic stress is involved in the progression of these neurological diseases.
Collapse
Affiliation(s)
- Wouter Huiting
- Department of Biomedical Sciences of Cells and Systems, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Suzanne L Dekker
- Department of Biomedical Sciences of Cells and Systems, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Joris C J van der Lienden
- Department of Biomedical Sciences of Cells and Systems, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Rafaella Mergener
- Department of Biomedical Sciences of Cells and Systems, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Maiara K Musskopf
- Department of Biomedical Sciences of Cells and Systems, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Gabriel V Furtado
- Department of Biomedical Sciences of Cells and Systems, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Emma Gerrits
- Department of Biomedical Sciences of Cells and Systems, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - David Coit
- Laboratory of Cellular and Structural Biology, The Rockefeller University, New York, United States
| | - Mehrnoosh Oghbaie
- Laboratory of Cellular and Structural Biology, The Rockefeller University, New York, United States.,European Research Institute for the Biology of Ageing, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Luciano H Di Stefano
- European Research Institute for the Biology of Ageing, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Hein Schepers
- Department of Biomedical Sciences of Cells and Systems, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Maria A W H van Waarde-Verhagen
- Department of Biomedical Sciences of Cells and Systems, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Suzanne Couzijn
- Department of Biomedical Sciences of Cells and Systems, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Lara Barazzuol
- Department of Biomedical Sciences of Cells and Systems, University Medical Center Groningen, University of Groningen, Groningen, Netherlands.,Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - John LaCava
- Laboratory of Cellular and Structural Biology, The Rockefeller University, New York, United States.,European Research Institute for the Biology of Ageing, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Harm H Kampinga
- Department of Biomedical Sciences of Cells and Systems, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Steven Bergink
- Department of Biomedical Sciences of Cells and Systems, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| |
Collapse
|
14
|
Zaepfel BL, Rothstein JD. Polyadenylated RNA and RNA-Binding Proteins Exhibit Unique Response to Hyperosmotic Stress. Front Cell Dev Biol 2021; 9:809859. [PMID: 34970554 PMCID: PMC8712688 DOI: 10.3389/fcell.2021.809859] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Accepted: 11/25/2021] [Indexed: 11/13/2022] Open
Abstract
Stress granule formation is a complex and rapidly evolving process that significantly disrupts cellular metabolism in response to a variety of cellular stressors. Recently, it has become evident that different chemical stressors lead to the formation of compositionally distinct stress granules. However, it is unclear which proteins are required for the formation of stress granules under different conditions. In addition, the effect of various stressors on polyadenylated RNA metabolism remains enigmatic. Here, we demonstrate that G3BP1/2, which are common stress granule components, are not required for the formation of stress granules specifically during osmotic stress induced by sorbitol and related polyols. Furthermore, sorbitol-induced osmotic stress leads to significant depletion of nuclear polyadenylated RNA, a process that we demonstrate is dependent on active mRNA export, as well as cytoplasmic and subnuclear shifts in the presence of many nuclear RNA-binding proteins. We assessed the function of multiple shifted RBPs and found that hnRNP U, but not TDP-43 or hnRNP I, exhibit reduced function following this cytoplasmic shift. Finally, we observe that multiple stress pathways lead to a significant reduction in transcription, providing a possible explanation for our inability to observe loss of TDP-43 or hnRNP I function. Overall, we identify unique outcomes following osmotic stress that provide important insight into the regulation of RNA-binding protein localization and function.
Collapse
Affiliation(s)
- Benjamin L. Zaepfel
- Biochemistry, Cellular and Molecular Biology Program, Johns Hopkins University School of Medicine, Baltimore, MD, United States
- Molecular Biology and Genetics Department, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Jeffrey D. Rothstein
- Brain Science Institute, Johns Hopkins University School of Medicine, Baltimore, MD, United States
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| |
Collapse
|
15
|
Parkin beyond Parkinson’s Disease—A Functional Meaning of Parkin Downregulation in TDP-43 Proteinopathies. Cells 2021; 10:cells10123389. [PMID: 34943897 PMCID: PMC8699658 DOI: 10.3390/cells10123389] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 11/27/2021] [Accepted: 11/29/2021] [Indexed: 12/15/2022] Open
Abstract
Parkin and PINK1 are key regulators of mitophagy, an autophagic pathway for selective elimination of dysfunctional mitochondria. To this date, parkin depletion has been associated with recessive early onset Parkinson’s disease (PD) caused by loss-of-function mutations in the PARK2 gene, while, in sporadic PD, the activity and abundance of this protein can be compromised by stress-related modifications. Intriguingly, research in recent years has shown that parkin depletion is not limited to PD but is also observed in other neurodegenerative diseases—especially those characterized by TDP-43 proteinopathies, such as amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD). Here, we discuss the evidence of parkin downregulation in these disease phenotypes, its emerging connections with TDP-43, and its possible functional implications.
Collapse
|
16
|
de Mena L, Lopez-Scarim J, Rincon-Limas DE. TDP-43 and ER Stress in Neurodegeneration: Friends or Foes? Front Mol Neurosci 2021; 14:772226. [PMID: 34759799 PMCID: PMC8573113 DOI: 10.3389/fnmol.2021.772226] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Accepted: 09/30/2021] [Indexed: 02/05/2023] Open
Abstract
Nuclear depletion, abnormal modification, and cytoplasmic aggregation of TAR DNA-binding protein 43 (TDP-43) are linked to a group of fatal neurodegenerative diseases called TDP-43 proteinopathies, which include amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD). Although our understanding of the physiological function of TDP-43 is rapidly advancing, the molecular mechanisms associated with its pathogenesis remain poorly understood. Accumulating evidence suggests that endoplasmic reticulum (ER) stress and the unfolded protein response (UPR) are important players in TDP-43 pathology. However, while neurons derived from autopsied ALS and FTLD patients revealed TDP-43 deposits in the ER and displayed UPR activation, data originated from in vitro and in vivo TDP-43 models produced contradictory results. In this review, we will explore the complex interplay between TDP-43 pathology, ER stress, and the UPR by breaking down the evidence available in the literature and addressing the reasons behind these discrepancies. We also highlight underexplored areas and key unanswered questions in the field. A better synchronization and integration of methodologies, models, and mechanistic pathways will be crucial to discover the true nature of the TDP-43 and ER stress relationship and, ultimately, to uncover the full therapeutic potential of the UPR.
Collapse
Affiliation(s)
- Lorena de Mena
- Department of Neurology, McKnight Brain Institute, and Norman Fixel Institute for Neurological Diseases, University of Florida, Gainesville, FL, United States
| | - Joshua Lopez-Scarim
- Department of Neurology, McKnight Brain Institute, and Norman Fixel Institute for Neurological Diseases, University of Florida, Gainesville, FL, United States
| | - Diego E Rincon-Limas
- Department of Neurology, McKnight Brain Institute, and Norman Fixel Institute for Neurological Diseases, University of Florida, Gainesville, FL, United States.,Department of Neuroscience, Center for Translational Research in Neurodegenerative Disease, University of Florida, Gainesville, FL, United States.,Genetics Institute, University of Florida, Gainesville, FL, United States
| |
Collapse
|
17
|
Kundinger SR, Dammer EB, Yin L, Hurst C, Shapley S, Ping L, Khoshnevis S, Ghalei H, Duong DM, Seyfried NT. Phosphorylation regulates arginine-rich RNA-binding protein solubility and oligomerization. J Biol Chem 2021; 297:101306. [PMID: 34673031 PMCID: PMC8569591 DOI: 10.1016/j.jbc.2021.101306] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 10/05/2021] [Accepted: 10/13/2021] [Indexed: 12/16/2022] Open
Abstract
Posttranslational modifications (PTMs) such as phosphorylation of RNA-binding proteins (RBPs) regulate several critical steps in RNA metabolism, including spliceosome assembly, alternative splicing, and mRNA export. Notably, serine-/arginine- (SR)-rich RBPs are densely phosphorylated compared with the remainder of the proteome. Previously, we showed that dephosphorylation of the splicing factor SRSF2 regulated increased interactions with similar arginine-rich RBPs U1-70K and LUC7L3. However, the large-scale functional and structural impact of these modifications on RBPs remains unclear. In this work, we dephosphorylated nuclear extracts using phosphatase in vitro and analyzed equal amounts of detergent-soluble and -insoluble fractions by mass-spectrometry-based proteomics. Correlation network analysis resolved 27 distinct modules of differentially soluble nucleoplasm proteins. We found classes of arginine-rich RBPs that decrease in solubility following dephosphorylation and enrich the insoluble pelleted fraction, including the SR protein family and the SR-like LUC7L RBP family. Importantly, increased insolubility was not observed across broad classes of RBPs. We determined that phosphorylation regulated SRSF2 structure, as dephosphorylated SRSF2 formed high-molecular-weight oligomeric species in vitro. Reciprocally, phosphorylation of SRSF2 by serine/arginine protein kinase 2 (SRPK2) in vitro decreased high-molecular-weight SRSF2 species formation. Furthermore, upon pharmacological inhibition of SRPKs in mammalian cells, we observed SRSF2 cytoplasmic mislocalization and increased formation of cytoplasmic granules as well as cytoplasmic tubular structures that associated with microtubules by immunocytochemical staining. Collectively, these findings demonstrate that phosphorylation may be a critical modification that prevents arginine-rich RBP insolubility and oligomerization.
Collapse
Affiliation(s)
- Sean R Kundinger
- Department of Biochemistry, Emory University, Atlanta, Georgia, USA
| | - Eric B Dammer
- Department of Biochemistry, Emory University, Atlanta, Georgia, USA
| | - Luming Yin
- Department of Biochemistry, Emory University, Atlanta, Georgia, USA
| | - Cheyenne Hurst
- Department of Biochemistry, Emory University, Atlanta, Georgia, USA
| | - Sarah Shapley
- Department of Biochemistry, Emory University, Atlanta, Georgia, USA
| | - Lingyan Ping
- Department of Biochemistry, Emory University, Atlanta, Georgia, USA
| | | | - Homa Ghalei
- Department of Biochemistry, Emory University, Atlanta, Georgia, USA
| | - Duc M Duong
- Department of Biochemistry, Emory University, Atlanta, Georgia, USA
| | - Nicholas T Seyfried
- Department of Biochemistry, Emory University, Atlanta, Georgia, USA; Department of Neurology, Emory University School of Medicine, Atlanta, Georgia, USA.
| |
Collapse
|
18
|
Corbet GA, Wheeler JR, Parker R, Weskamp K. TDP43 ribonucleoprotein granules: physiologic function to pathologic aggregates. RNA Biol 2021; 18:128-138. [PMID: 34412568 DOI: 10.1080/15476286.2021.1963099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
Ribonucleoprotein (RNP) assemblies are ubiquitous in eukaryotic cells and have functions throughout RNA transcription, splicing, and stability. Of the RNA-binding proteins that form RNPs, TAR DNA-binding protein of 43 kD (TDP43) is of particular interest due to its essential nature and its association with disease. TDP43 plays critical roles in RNA metabolism, many of which require its recruitment to RNP granules such as stress granules, myo-granules, and neuronal transport granules. Moreover, the presence of cytoplasmic TDP43-positive inclusions is a pathological hallmark of several neurodegenerative diseases. Despite the pervasiveness of TDP43 aggregates, TDP43 mutations are exceedingly rare, suggesting that aggregation may be linked to dysregulation of TDP43 function. Oligomerization is a part of normal TDP43 function; thus, it is of interest to understand what triggers the irreversible aggregation that is seen in disease. Herein, we examine TDP43 functions, particularly in RNP granules, and the mechanisms which may explain pathological TDP43 aggregation.
Collapse
Affiliation(s)
- Giulia Ada Corbet
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO, USA
| | | | - Roy Parker
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO, USA.,Department of Chemistry, Howard Hughes Medical Institute, Chevy Chase, MD, USA
| | | |
Collapse
|
19
|
Esposto JC, Martic S. Phosphorylated TAR DNA-Binding Protein-43: Aggregation and Antibody-Based Inhibition. Biochim Biophys Acta Mol Basis Dis 2021; 1867:166234. [PMID: 34339840 DOI: 10.1016/j.bbadis.2021.166234] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 07/21/2021] [Accepted: 07/27/2021] [Indexed: 12/28/2022]
Abstract
TAR DNA-binding protein-43 (TDP-43) pathology, including fibrillar aggregates and mutations, develops in amyotrophic lateral sclerosis (ALS), frontotemporal lobar degeneration (FTLD) and limbic-predominant age-related TDP-43 encephalopathy (LATE). Hyperphosphorylation and aggregation of TDP-43 contribute to pathology and are viable therapeutic targets for ALS. In vivo inhibition of TDP-43 aggregation was evaluated using anti-TDP-43 antibodies with promising outcomes. However, the exact mechanism of antibody-based inhibition targeting TDP-43 is not well understood but may lead to the identification of viable immunotherapies. Herein, the mechanism of in vitro aggregation of phosphorylated TDP-43 was explored, and the anti-TDP-43 antibodies tested for their inhibitor efficacies. Specifically, the aggregation of phosphorylated full-length TDP-43 protein (pS410) was monitored by transmission electron microscopy (TEM), turbidity absorbance, and thioflavin (ThT). The protein aggregates were insoluble, ThT-positive and characterized with heterogeneous morphologies (fibers, amorphous structures). Antibodies specific to epitopes 178-393 and 256-269, within the RRM2-CTD domain, reduced the formation of β-sheets and insoluble aggregates, at low antibody loading (antibody: protein ratio = 1 ug/mL: 45 ug/mL). Inhibition outcomes were highly dependent on the type and loading of antibodies, indicating dual functionality of such inhibitors, as aggregation inhibitors or aggregation promoters. Anti-SOD1 and anti-tau antibodies were not effective inhibitors against TDP-43 aggregation, indicating selective inhibition.
Collapse
Affiliation(s)
- Josephine C Esposto
- Environmental and Life Sciences, Trent University, Peterborough, Ontario, Canada K9L 0G2.
| | - Sanela Martic
- Department of Forensic Science, Trent University, Peterborough, Ontario, Canada K9L 0G2.
| |
Collapse
|
20
|
Mohanan G, Das A, Rajyaguru PI. Genotoxic stress response: What is the role of cytoplasmic mRNA fate? Bioessays 2021; 43:e2000311. [PMID: 34096096 DOI: 10.1002/bies.202000311] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 05/15/2021] [Accepted: 05/18/2021] [Indexed: 12/18/2022]
Abstract
Genotoxic stress leads to DNA damage which can be detrimental to the cell. A well-orchestrated cellular response is mounted to manage and repair the genotoxic stress-induced DNA damage. Our understanding of genotoxic stress response is derived mainly from studies focused on transcription, mRNA splicing, and protein turnover. Surprisingly not as much is understood about the role of mRNA translation and decay in genotoxic stress response. This is despite the fact that regulation of gene expression at the level of mRNA translation and decay plays a critical role in a myriad of cellular processes. This review aims to summarize some of the known findings of the role of mRNA translation and decay by focusing on two categories of examples. We discuss examples of mRNA whose fates are regulated in the cytoplasm and RNA-binding proteins that regulate mRNA fates in response to genotoxic stress.
Collapse
Affiliation(s)
- Gayatri Mohanan
- Department of Biochemistry, Indian Institute of Science, Bangalore, India
| | - Amiyaranjan Das
- Department of Biochemistry, Indian Institute of Science, Bangalore, India
| | | |
Collapse
|
21
|
PARP-1 activation leads to cytosolic accumulation of TDP-43 in neurons. Neurochem Int 2021; 148:105077. [PMID: 34082062 DOI: 10.1016/j.neuint.2021.105077] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Accepted: 05/20/2021] [Indexed: 11/21/2022]
Abstract
Oxidative stress in neurodegenerative disease leads to poly(ADP-ribose) polymerase 1 (PARP-1) overactivation and subsequent cell death via excessive generation of Poly(ADP-ribose) polymer (PAR). PAR binds to neurodegenerative disease linked protein TAR DNA binding protein of 43 kDa (TDP-43). However, the consequence of this interaction is not yet fully understood. TDP-43 translocates from the nucleus to the cytoplasm in response to oxidative stress, but the mechanism of stress-induced translocation remains unknown. We used N-methyl-N-nitroso-N'-nitroguanidine (MNNG) and oxygen-glucose deprivation (OGD) in mouse neuronal cultures to activate PARP-1 and observed that pharmacological inhibition of PARP-1 blocked the cytosolic translocation of TDP-43. PARP-1 inhibition is also neuroprotective against both MNNG and OGD, suggesting that PARP inhibitors could play a role in the neuroprotective role in neurodegenerative diseases involving TDP-43. Together, these data present the novel finding that TDP-43 translocation depends on PARP-1 activation and set a ground for future research of how PARP-1 activation or PAR binding to TDP-43 may facilitate its cytosolic accumulation.
Collapse
|
22
|
Chhangani D, Martín-Peña A, Rincon-Limas DE. Molecular, functional, and pathological aspects of TDP-43 fragmentation. iScience 2021; 24:102459. [PMID: 34013172 PMCID: PMC8113996 DOI: 10.1016/j.isci.2021.102459] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Transactive response DNA binding protein 43 (TDP-43) is a DNA/RNA binding protein involved in transcriptional regulation and RNA processing. It is linked to sporadic and familial amyotrophic lateral sclerosis and frontotemporal lobar degeneration. TDP-43 is predominantly nuclear, but it translocates to the cytoplasm under pathological conditions. Cytoplasmic accumulation, phosphorylation, ubiquitination and truncation of TDP-43 are the main hallmarks of TDP-43 proteinopathies. Among these processes, the pathways leading to TDP-43 fragmentation remain poorly understood. We review here the molecular and biochemical properties of several TDP-43 fragments, the mechanisms and factors mediating their production, and their potential role in disease progression. We also address the presence of TDP-43 C-terminal fragments in several neurological disorders, including Alzheimer's disease, and highlight their respective implications. Finally, we discuss features of animal models expressing TDP-43 fragments as well as recent therapeutic strategies to approach TDP-43 truncation.
Collapse
Affiliation(s)
- Deepak Chhangani
- Department of Neurology, McKnight Brain Institute, and Norman Fixel Institute for Neurological Diseases, University of Florida, Gainesville, FL 32611, USA
| | - Alfonso Martín-Peña
- Department of Neurology, McKnight Brain Institute, and Norman Fixel Institute for Neurological Diseases, University of Florida, Gainesville, FL 32611, USA
| | - Diego E Rincon-Limas
- Department of Neurology, McKnight Brain Institute, and Norman Fixel Institute for Neurological Diseases, University of Florida, Gainesville, FL 32611, USA.,Department of Neuroscience, Center for Translational Research in Neurodegenerative Disease, University of Florida, Gainesville, FL 32611, USA.,Genetics Institute, University of Florida, Gainesville, FL 32611, USA
| |
Collapse
|
23
|
Asakawa K, Handa H, Kawakami K. Multi-phaseted problems of TDP-43 in selective neuronal vulnerability in ALS. Cell Mol Life Sci 2021; 78:4453-4465. [PMID: 33709256 PMCID: PMC8195926 DOI: 10.1007/s00018-021-03792-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 02/03/2021] [Accepted: 02/18/2021] [Indexed: 10/28/2022]
Abstract
Transactive response DNA-binding protein 43 kDa (TDP-43) encoded by the TARDBP gene is an evolutionarily conserved heterogeneous nuclear ribonucleoprotein (hnRNP) that regulates multiple steps of RNA metabolism, and its cytoplasmic aggregation characterizes degenerating motor neurons in amyotrophic lateral sclerosis (ALS). In most ALS cases, cytoplasmic TDP-43 aggregation occurs in the absence of mutations in the coding sequence of TARDBP. Thus, a major challenge in ALS research is to understand the nature of pathological changes occurring in wild-type TDP-43 and to explore upstream events in intracellular and extracellular milieu that promote the pathological transition of TDP-43. Despite the inherent obstacles to analyzing TDP-43 dynamics in in vivo motor neurons due to their anatomical complexity and inaccessibility, recent studies using cellular and animal models have provided important mechanistic insights into potential links between TDP-43 and motor neuron vulnerability in ALS. This review is intended to provide an overview of the current literature on the function and regulation of TDP-43-containing RNP granules or membraneless organelles, as revealed by various models, and to discuss the potential mechanisms by which TDP-43 can cause selective vulnerability of motor neurons in ALS.
Collapse
Affiliation(s)
- Kazuhide Asakawa
- Department of Chemical Biology, Tokyo Medical University, Shinjuku-ku, Tokyo, 160-8402, Japan.
- Division of Molecular and Developmental Biology, National Institute of Genetics, 1111 Yata, Mishima, Shizuoka, 411-8540, Japan.
- Department of Genetics, Graduate University for Advanced Studies (SOKENDAI), 1111 Yata, Mishima, Shizuoka, 411-8540, Japan.
| | - Hiroshi Handa
- Department of Chemical Biology, Tokyo Medical University, Shinjuku-ku, Tokyo, 160-8402, Japan
| | - Koichi Kawakami
- Division of Molecular and Developmental Biology, National Institute of Genetics, 1111 Yata, Mishima, Shizuoka, 411-8540, Japan
- Department of Genetics, Graduate University for Advanced Studies (SOKENDAI), 1111 Yata, Mishima, Shizuoka, 411-8540, Japan
| |
Collapse
|
24
|
Velázquez-Cruz A, Baños-Jaime B, Díaz-Quintana A, De la Rosa MA, Díaz-Moreno I. Post-translational Control of RNA-Binding Proteins and Disease-Related Dysregulation. Front Mol Biosci 2021; 8:658852. [PMID: 33987205 PMCID: PMC8111222 DOI: 10.3389/fmolb.2021.658852] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 03/22/2021] [Indexed: 12/20/2022] Open
Abstract
Cell signaling mechanisms modulate gene expression in response to internal and external stimuli. Cellular adaptation requires a precise and coordinated regulation of the transcription and translation processes. The post-transcriptional control of mRNA metabolism is mediated by the so-called RNA-binding proteins (RBPs), which assemble with specific transcripts forming messenger ribonucleoprotein particles of highly dynamic composition. RBPs constitute a class of trans-acting regulatory proteins with affinity for certain consensus elements present in mRNA molecules. However, these regulators are subjected to post-translational modifications (PTMs) that constantly adjust their activity to maintain cell homeostasis. PTMs can dramatically change the subcellular localization, the binding affinity for RNA and protein partners, and the turnover rate of RBPs. Moreover, the ability of many RBPs to undergo phase transition and/or their recruitment to previously formed membrane-less organelles, such as stress granules, is also regulated by specific PTMs. Interestingly, the dysregulation of PTMs in RBPs has been associated with the pathophysiology of many different diseases. Abnormal PTM patterns can lead to the distortion of the physiological role of RBPs due to mislocalization, loss or gain of function, and/or accelerated or disrupted degradation. This Mini Review offers a broad overview of the post-translational regulation of selected RBPs and the involvement of their dysregulation in neurodegenerative disorders, cancer and other pathologies.
Collapse
Affiliation(s)
- Alejandro Velázquez-Cruz
- Instituto de Investigaciones Químicas, Centro de Investigaciones Científicas Isla de la Cartuja, Universidad de Sevilla, Consejo Superior de Investigaciones Científicas, Seville, Spain
| | - Blanca Baños-Jaime
- Instituto de Investigaciones Químicas, Centro de Investigaciones Científicas Isla de la Cartuja, Universidad de Sevilla, Consejo Superior de Investigaciones Científicas, Seville, Spain
| | - Antonio Díaz-Quintana
- Instituto de Investigaciones Químicas, Centro de Investigaciones Científicas Isla de la Cartuja, Universidad de Sevilla, Consejo Superior de Investigaciones Científicas, Seville, Spain
| | - Miguel A De la Rosa
- Instituto de Investigaciones Químicas, Centro de Investigaciones Científicas Isla de la Cartuja, Universidad de Sevilla, Consejo Superior de Investigaciones Científicas, Seville, Spain
| | - Irene Díaz-Moreno
- Instituto de Investigaciones Químicas, Centro de Investigaciones Científicas Isla de la Cartuja, Universidad de Sevilla, Consejo Superior de Investigaciones Científicas, Seville, Spain
| |
Collapse
|
25
|
Guo Q, Dammer EB, Zhou M, Kundinger SR, Gearing M, Lah JJ, Levey AI, Shulman JM, Seyfried NT. Targeted Quantification of Detergent-Insoluble RNA-Binding Proteins in Human Brain Reveals Stage and Disease Specific Co-aggregation in Alzheimer's Disease. Front Mol Neurosci 2021; 14:623659. [PMID: 33815056 PMCID: PMC8014091 DOI: 10.3389/fnmol.2021.623659] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 02/12/2021] [Indexed: 01/02/2023] Open
Abstract
Core spliceosome and related RNA-binding proteins aggregate in Alzheimer’s disease (AD) brain even in early asymptomatic stages (AsymAD) of disease. To assess the specificity of RNA-binding protein aggregation in AD, we developed a targeted mass spectrometry approach to quantify broad classes of RNA-binding proteins with other pathological proteins including tau and amyloid beta (Aβ) in detergent insoluble fractions from control, AsymAD, AD and Parkinson’s disease (PD) brain. Relative levels of specific insoluble RNA-binding proteins across different disease groups correlated with accumulation of Aβ and tau aggregates. RNA-binding proteins, including splicing factors with homology to the basic-acidic dipeptide repeats of U1-70K, preferentially aggregated in AsymAD and AD. In contrast, PD brain aggregates were relatively depleted of many RNA-binding proteins compared to AsymAD and AD groups. Correlation network analyses resolved 29 distinct modules of co-aggregating proteins including modules linked to spliceosome assembly, nuclear speckles and RNA splicing. Modules related to spliceosome assembly and nuclear speckles showed stage-specific enrichment of insoluble RBPs from AsymAD and AD brains, whereas the RNA splicing module was reduced specifically in PD. Collectively, this work identifies classes of RNA-binding proteins that distinctly co-aggregate in detergent-insoluble fractions across the specific neurodegenerative diseases we examined.
Collapse
Affiliation(s)
- Qi Guo
- Department of Biochemistry, School of Medicine, Emory University, Atlanta, GA, United States
| | - Eric B Dammer
- Department of Biochemistry, School of Medicine, Emory University, Atlanta, GA, United States.,Goizueta Alzheimer's Disease Research Center, School of Medicine, Emory University, Atlanta, GA, United States
| | - Maotian Zhou
- Department of Biochemistry, School of Medicine, Emory University, Atlanta, GA, United States
| | - Sean R Kundinger
- Department of Biochemistry, School of Medicine, Emory University, Atlanta, GA, United States
| | - Marla Gearing
- Goizueta Alzheimer's Disease Research Center, School of Medicine, Emory University, Atlanta, GA, United States.,Department of Pathology and Laboratory Medicine, School of Medicine, Emory University, Atlanta, GA, United States
| | - James J Lah
- Goizueta Alzheimer's Disease Research Center, School of Medicine, Emory University, Atlanta, GA, United States.,Department of Neurology, School of Medicine, Emory University, Atlanta, GA, United States
| | - Allan I Levey
- Goizueta Alzheimer's Disease Research Center, School of Medicine, Emory University, Atlanta, GA, United States.,Department of Neurology, School of Medicine, Emory University, Atlanta, GA, United States
| | - Joshua M Shulman
- Departments of Neurology, Neuroscience and Molecular & Human Genetics, Baylor College of Medicine, Houston, TX, United States.,Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, United States
| | - Nicholas T Seyfried
- Department of Biochemistry, School of Medicine, Emory University, Atlanta, GA, United States.,Goizueta Alzheimer's Disease Research Center, School of Medicine, Emory University, Atlanta, GA, United States.,Department of Neurology, School of Medicine, Emory University, Atlanta, GA, United States
| |
Collapse
|
26
|
Asakawa K, Handa H, Kawakami K. Illuminating ALS Motor Neurons With Optogenetics in Zebrafish. Front Cell Dev Biol 2021; 9:640414. [PMID: 33816488 PMCID: PMC8012537 DOI: 10.3389/fcell.2021.640414] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Accepted: 02/22/2021] [Indexed: 11/13/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal neurological disorder characterized by progressive degeneration of motor neurons in the brain and spinal cord. Spinal motor neurons align along the spinal cord length within the vertebral column, and extend long axons to connect with skeletal muscles covering the body surface. Due to this anatomy, spinal motor neurons are among the most difficult cells to observe in vivo. Larval zebrafish have transparent bodies that allow non-invasive visualization of whole cells of single spinal motor neurons, from somas to the neuromuscular synapses. This unique feature, combined with its amenability to genome editing, pharmacology, and optogenetics, enables functional analyses of ALS-associated proteins in the spinal motor neurons in vivo with subcellular resolution. Here, we review the zebrafish skeletal neuromuscular system and the optical methods used to study it. We then introduce a recently developed optogenetic zebrafish ALS model that uses light illumination to control oligomerization, phase transition and aggregation of the ALS-associated DNA/RNA-binding protein called TDP-43. Finally, we will discuss how this disease-in-a-fish ALS model can help solve key questions about ALS pathogenesis and lead to new ALS therapeutics.
Collapse
Affiliation(s)
- Kazuhide Asakawa
- Department of Chemical Biology, Tokyo Medical University, Tokyo, Japan
| | - Hiroshi Handa
- Department of Chemical Biology, Tokyo Medical University, Tokyo, Japan
| | - Koichi Kawakami
- Division of Molecular and Developmental Biology, National Institute of Genetics, Mishima, Japan.,Department of Genetics, Graduate University for Advanced Studies (SOKENDAI), Mishima, Japan
| |
Collapse
|
27
|
Ma P, Li Y, Wang H, Mao B. Haploinsufficiency of the TDP43 ubiquitin E3 ligase RNF220 leads to ALS-like motor neuron defects in the mouse. J Mol Cell Biol 2021; 13:374-382. [PMID: 33386850 PMCID: PMC8373269 DOI: 10.1093/jmcb/mjaa072] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Revised: 09/16/2020] [Accepted: 10/04/2020] [Indexed: 11/14/2022] Open
Abstract
TDP43 pathology is seen in a large majority of amyotrophic lateral sclerosis (ALS) cases, suggesting a central pathogenic role of this regulatory protein. Clarifying the molecular mechanism controlling TDP43 stability and subcellular location might provide important insights into ALS therapy. The ubiquitin E3 ligase RNF220 is involved in different neural developmental processes through various molecular targets in the mouse. Here, we report that the RNF220+/− mice showed progressively decreasing mobility to different extents, some of which developed typical ALS pathological characteristics in spinal motor neurons, including TDP43 cytoplasmic accumulation, atrocytosis, muscle denervation, and atrophy. Mechanistically, RNF220 interacts with TDP43 in vitro and in vivo and promotes its polyubiquitination and proteasomal degradation. In conclusion, we propose that RNF220 might be a modifier of TDP43 function in vivo and contribute to TDP43 pathology in neurodegenerative disease like ALS.
Collapse
Affiliation(s)
- Pengcheng Ma
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
| | - Yuwei Li
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China.,Kunming College of Life Science, University of Chinese Academy of Sciences, Kunming, China
| | - Huishan Wang
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China.,Kunming College of Life Science, University of Chinese Academy of Sciences, Kunming, China
| | - Bingyu Mao
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China.,Center for Excellence in Animal Evolution and Genetics, Chinese Academy of Sciences, Kunming, China
| |
Collapse
|
28
|
Buratti E. Trends in Understanding the Pathological Roles of TDP-43 and FUS Proteins. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1281:243-267. [PMID: 33433879 DOI: 10.1007/978-3-030-51140-1_15] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Following the discovery of TDP-43 and FUS involvement in amyotrophic lateral sclerosis (ALS) and frontotemporal lobar dementia (FTLD), the major challenge in the field has been to understand their physiological functions, both in normal and disease conditions. The hope is that this knowledge will improve our understanding of disease and lead to the development of effective therapeutic options. Initially, the focus has been directed at characterizing the role of these proteins in the control of RNA metabolism, because the main function of TDP-43 and FUS is to bind coding and noncoding RNAs to regulate their life cycle within cells. As a result, we now have an in-depth picture of the alterations that occur in RNA metabolism following their aggregation in various ALS/FTLD models and, to a somewhat lesser extent, in patients' brains. In parallel, progress has been made with regard to understanding how aggregation of these proteins occurs in neurons, how it can spread in different brain regions, and how these changes affect various metabolic cellular pathways to result in neuronal death. The aim of this chapter will be to provide a general overview of the trending topics in TDP-43 and FUS investigations and to highlight what might represent the most promising avenues of research in the years to come.
Collapse
Affiliation(s)
- Emanuele Buratti
- International Centre for Genetic Engineering and Biotechnology (ICGEB), Trieste, Italy.
| |
Collapse
|
29
|
Neumann M, Lee EB, Mackenzie IR. Frontotemporal Lobar Degeneration TDP-43-Immunoreactive Pathological Subtypes: Clinical and Mechanistic Significance. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1281:201-217. [PMID: 33433877 DOI: 10.1007/978-3-030-51140-1_13] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Frontotemporal lobar degeneration with TPD-43-immunoreactive pathology (FTLD-TDP) is subclassified based on the type and cortical laminar distribution of neuronal inclusions. The relevance of these pathological subtypes is supported by the presence of relatively specific clinical and genetic correlations. Recent evidence suggests that the different patterns of pathology are a reflection of biochemical differences in the pathological TDP-43 species, each of which is influenced by differing genetic factors. As a result, patient FTLD-TDP subtype may be an important factor to consider when developing biomarkers and targeted therapies for frontotemporal dementia. In this chapter, we first describe the pathological features, clinical and genetic correlations of the currently recognized FTLD-TDP subtypes. We then discuss a number of novel patterns of TDP-43 pathology. Finally, we provide an overview of what is currently known about the biochemical basis of the different FTLD-TDP subtypes and how this may explain the observed phenotypic and pathological heterogeneity.
Collapse
Affiliation(s)
- Manuela Neumann
- Department of Neuropathology, University of Tübingen, Tübingen, Germany.,DZNE, German Center for Neurodegenerative Diseases, Tübingen, Germany
| | - Edward B Lee
- Department of Pathology and Laboratory Medicine, and Center for Neurodegenerative Disease Research, University of Pennsylvania, Philadelphia, PA, USA
| | - Ian R Mackenzie
- Department of Pathology, University of British Columbia, Vancouver, BC, Canada. .,Department of Pathology, Vancouver General Hospital, Vancouver, BC, Canada.
| |
Collapse
|
30
|
Le Guerroué F, Youle RJ. Ubiquitin signaling in neurodegenerative diseases: an autophagy and proteasome perspective. Cell Death Differ 2020; 28:439-454. [PMID: 33208890 DOI: 10.1038/s41418-020-00667-x] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2020] [Revised: 10/28/2020] [Accepted: 10/30/2020] [Indexed: 12/13/2022] Open
Abstract
Ubiquitin signaling is a sequence of events driving the fate of a protein based on the type of ubiquitin modifications attached. In the case of neurodegenerative diseases, ubiquitin signaling is mainly associated with degradation signals to process aberrant proteins, which form aggregates often fatal for the brain cells. This signaling is often perturbed by the aggregates themselves and leads to the accumulation of toxic aggregates and inclusion bodies that are deleterious due to a toxic gain of function. Decrease in quality control pathways is often seen with age and is a critical onset for the development of neurodegeneration. Many aggregates are now thought to propagate in a prion-like manner, where mutated proteins acting like seeds are transitioning from cell to cell, converting normal proteins to toxic aggregates. Modulation of ubiquitin signaling, by stimulating ubiquitin ligase activation, is a potential therapeutic strategy to treat patients with neurodegeneration diseases.
Collapse
Affiliation(s)
- François Le Guerroué
- Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Richard J Youle
- Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, 20892, USA.
| |
Collapse
|
31
|
Marques RF, Engler JB, Küchler K, Jones RA, Lingner T, Salinas G, Gillingwater TH, Friese MA, Duncan KE. Motor neuron translatome reveals deregulation of SYNGR4 and PLEKHB1 in mutant TDP-43 amyotrophic lateral sclerosis models. Hum Mol Genet 2020; 29:2647-2661. [PMID: 32686835 PMCID: PMC7530531 DOI: 10.1093/hmg/ddaa140] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Revised: 06/18/2020] [Accepted: 06/30/2020] [Indexed: 12/11/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is an incurable neurological disease with progressive loss of motor neuron (MN) function in the brain and spinal cord. Mutations in TARDBP, encoding the RNA-binding protein TDP-43, are one cause of ALS, and TDP-43 mislocalization in MNs is a key pathological feature of >95% of ALS cases. While numerous studies support altered RNA regulation by TDP-43 as a major cause of disease, specific changes within MNs that trigger disease onset remain unclear. Here, we combined translating ribosome affinity purification (TRAP) with RNA sequencing to identify molecular changes in spinal MNs of TDP-43-driven ALS at motor symptom onset. By comparing the MN translatome of hTDP-43A315T mice to littermate controls and to mice expressing wild type hTDP-43, we identified hundreds of mRNAs that were selectively up- or downregulated in MNs. We validated the deregulated candidates Tex26, Syngr4, and Plekhb1 mRNAs in an independent TRAP experiment. Moreover, by quantitative immunostaining of spinal cord MNs, we found corresponding protein level changes for SYNGR4 and PLEKHB1. We also observed these changes in spinal MNs of an independent ALS mouse model caused by a different patient mutant allele of TDP-43, suggesting that they are general features of TDP-43-driven ALS. Thus, we identified SYNGR4 and PLEKHB1 to be deregulated in MNs at motor symptom onset in TDP-43-driven ALS models. This spatial and temporal pattern suggests that these proteins could be functionally important for driving the transition to the symptomatic phase of the disease.
Collapse
Affiliation(s)
- Rita F Marques
- Neuronal Translational Control Research Group, Center for Molecular Neurobiology Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg 20251, Germany
| | - Jan B Engler
- Institute of Neuroimmunology and Multiple Sclerosis, Center for Molecular Neurobiology Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg 20251, Germany
| | - Katrin Küchler
- Neuronal Translational Control Research Group, Center for Molecular Neurobiology Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg 20251, Germany
| | - Ross A Jones
- Edinburgh Medical School: Biomedical Sciences, University of Edinburgh, Edinburgh EH8 9XD, United Kingdom
| | - Thomas Lingner
- NGS—Integrative Genomics Core Unit (NIG), Institute of Human Genetics, University Medical Center Göttingen, Göttingen 37077, Germany
| | - Gabriela Salinas
- NGS—Integrative Genomics Core Unit (NIG), Institute of Human Genetics, University Medical Center Göttingen, Göttingen 37077, Germany
| | - Thomas H Gillingwater
- Edinburgh Medical School: Biomedical Sciences, University of Edinburgh, Edinburgh EH8 9XD, United Kingdom
| | - Manuel A Friese
- Institute of Neuroimmunology and Multiple Sclerosis, Center for Molecular Neurobiology Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg 20251, Germany
| | - Kent E Duncan
- Neuronal Translational Control Research Group, Center for Molecular Neurobiology Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg 20251, Germany
| |
Collapse
|
32
|
Hofmann S, Kedersha N, Anderson P, Ivanov P. Molecular mechanisms of stress granule assembly and disassembly. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2020; 1868:118876. [PMID: 33007331 DOI: 10.1016/j.bbamcr.2020.118876] [Citation(s) in RCA: 162] [Impact Index Per Article: 40.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 09/18/2020] [Accepted: 09/19/2020] [Indexed: 12/11/2022]
Abstract
Stress granules (SGs) are membrane-less ribonucleoprotein (RNP)-based cellular compartments that form in the cytoplasm of a cell upon exposure to various environmental stressors. SGs contain a large set of proteins, as well as mRNAs that have been stalled in translation as a result of stress-induced polysome disassembly. Despite the fact that SGs have been extensively studied for many years, their function is still not clear. They presumably help the cell to cope with the encountered stress, and facilitate the recovery process after stress removal upon which SGs disassemble. Aberrant formation of SGs and impaired SG disassembly majorly contribute to various pathological phenomena in cancer, viral infections, and neurodegeneration. The assembly of SGs is largely driven by liquid-liquid phase separation (LLPS), however, the molecular mechanisms behind that are not fully understood. Recent studies have proposed a novel mechanism for SG formation that involves the interplay of a large interaction network of mRNAs and proteins. Here, we review this novel concept of SG assembly, and discuss the current insights into SG disassembly.
Collapse
Affiliation(s)
- Sarah Hofmann
- Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Nancy Kedersha
- Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Paul Anderson
- Brigham and Women's Hospital, Harvard Medical School, Harvard Initiative for RNA Medicine, Boston, MA 02115, USA
| | - Pavel Ivanov
- Brigham and Women's Hospital, Harvard Medical School, Harvard Initiative for RNA Medicine, Boston, MA 02115, USA.
| |
Collapse
|
33
|
Proteostasis Failure in Neurodegenerative Diseases: Focus on Oxidative Stress. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2020; 2020:5497046. [PMID: 32308803 PMCID: PMC7140146 DOI: 10.1155/2020/5497046] [Citation(s) in RCA: 82] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Accepted: 03/03/2020] [Indexed: 12/11/2022]
Abstract
Protein homeostasis or proteostasis is an essential balance of cellular protein levels mediated through an extensive network of biochemical pathways that regulate different steps of the protein quality control, from the synthesis to the degradation. All proteins in a cell continuously turn over, contributing to development, differentiation, and aging. Due to the multiple interactions and connections of proteostasis pathways, exposure to stress conditions may cause various types of protein damage, altering cellular homeostasis and disrupting the entire network with additional cellular stress. Furthermore, protein misfolding and/or alterations during protein synthesis results in inactive or toxic proteins, which may overload the degradation mechanisms. The maintenance of a balanced proteome, preventing the formation of impaired proteins, is accomplished by two major catabolic routes: the ubiquitin proteasomal system (UPS) and the autophagy-lysosomal system. The proteostasis network is particularly important in nondividing, long-lived cells, such as neurons, as its failure is implicated with the development of neurodegenerative diseases, such as Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis. These neurological disorders share common risk factors such as aging, oxidative stress, environmental stress, and protein dysfunction, all of which alter cellular proteostasis, suggesting that general mechanisms controlling proteostasis may underlay the etiology of these diseases. In this review, we describe the major pathways of cellular proteostasis and discuss how their disruption contributes to the onset and progression of neurodegenerative diseases, focusing on the role of oxidative stress.
Collapse
|
34
|
Hergesheimer RC, Chami AA, de Assis DR, Vourc'h P, Andres CR, Corcia P, Lanznaster D, Blasco H. The debated toxic role of aggregated TDP-43 in amyotrophic lateral sclerosis: a resolution in sight? Brain 2020; 142:1176-1194. [PMID: 30938443 PMCID: PMC6487324 DOI: 10.1093/brain/awz078] [Citation(s) in RCA: 111] [Impact Index Per Article: 27.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Revised: 02/11/2019] [Accepted: 02/16/2019] [Indexed: 12/11/2022] Open
Abstract
Transactive response DNA-binding protein-43 (TDP-43) is an RNA/DNA binding protein that forms phosphorylated and ubiquitinated aggregates in the cytoplasm of motor neurons in amyotrophic lateral sclerosis, which is a hallmark of this disease. Amyotrophic lateral sclerosis is a neurodegenerative condition affecting the upper and lower motor neurons. Even though the aggregative property of TDP-43 is considered a cornerstone of amyotrophic lateral sclerosis, there has been major controversy regarding the functional link between TDP-43 aggregates and cell death. In this review, we attempt to reconcile the current literature surrounding this debate by discussing the results and limitations of the published data relating TDP-43 aggregates to cytotoxicity, as well as therapeutic perspectives of TDP-43 aggregate clearance. We point out key data suggesting that the formation of TDP-43 aggregates and the capacity to self-template and propagate among cells as a 'prion-like' protein, another pathological property of TDP-43 aggregates, are a significant cause of motor neuronal death. We discuss the disparities among the various studies, particularly with respect to the type of models and the different forms of TDP-43 used to evaluate cellular toxicity. We also examine how these disparities can interfere with the interpretation of the results pertaining to a direct toxic effect of TDP-43 aggregates. Furthermore, we present perspectives for improving models in order to better uncover the toxic role of aggregated TDP-43. Finally, we review the recent studies on the enhancement of the cellular clearance mechanisms of autophagy, the ubiquitin proteasome system, and endocytosis in an attempt to counteract TDP-43 aggregation-induced toxicity. Altogether, the data available so far encourage us to suggest that the cytoplasmic aggregation of TDP-43 is key for the neurodegeneration observed in motor neurons in patients with amyotrophic lateral sclerosis. The corresponding findings provide novel avenues toward early therapeutic interventions and clinical outcomes for amyotrophic lateral sclerosis management.
Collapse
Affiliation(s)
| | - Anna A Chami
- UMR 1253, iBRAIN, Université de Tours, INSERM, Tours, France
| | | | - Patrick Vourc'h
- UMR 1253, iBRAIN, Université de Tours, INSERM, Tours, France.,CHU de Tours, Service de Biochimie et Biologie Moléculaire, Tours, France
| | - Christian R Andres
- UMR 1253, iBRAIN, Université de Tours, INSERM, Tours, France.,CHU de Tours, Service de Biochimie et Biologie Moléculaire, Tours, France
| | - Philippe Corcia
- UMR 1253, iBRAIN, Université de Tours, INSERM, Tours, France.,CHU de Tours, Service de Neurologie, Tours, France
| | | | - Hélène Blasco
- UMR 1253, iBRAIN, Université de Tours, INSERM, Tours, France.,CHU de Tours, Service de Biochimie et Biologie Moléculaire, Tours, France
| |
Collapse
|
35
|
Weskamp K, Tank EM, Miguez R, McBride JP, Gómez NB, White M, Lin Z, Gonzalez CM, Serio A, Sreedharan J, Barmada SJ. Shortened TDP43 isoforms upregulated by neuronal hyperactivity drive TDP43 pathology in ALS. J Clin Invest 2020; 130:1139-1155. [PMID: 31714900 PMCID: PMC7269575 DOI: 10.1172/jci130988] [Citation(s) in RCA: 72] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Accepted: 11/06/2019] [Indexed: 12/13/2022] Open
Abstract
Cortical hyperexcitability and mislocalization of the RNA-binding protein TDP43 are highly conserved features in amyotrophic lateral sclerosis (ALS). Nevertheless, the relationship between these phenomena remains poorly defined. Here, we showed that hyperexcitability recapitulates TDP43 pathology by upregulating shortened TDP43 (sTDP43) splice isoforms. These truncated isoforms accumulated in the cytoplasm and formed insoluble inclusions that sequestered full-length TDP43 via preserved N-terminal interactions. Consistent with these findings, sTDP43 overexpression was toxic to mammalian neurons, suggesting neurodegeneration arising from complementary gain- and loss-of-function mechanisms. In humans and mice, sTDP43 transcripts were enriched in vulnerable motor neurons, and we observed a striking accumulation of sTDP43 within neurons and glia of ALS patients. Collectively, these studies uncover a pathogenic role for alternative TDP43 isoforms in ALS, and implicate sTDP43 as a key contributor to the susceptibility of motor neurons in this disorder.
Collapse
Affiliation(s)
| | | | | | - Jonathon P. McBride
- Department of Neurology
- Cellular and Molecular Biology Program, Michigan Medicine, University of Michigan, Ann Arbor, Michigan, USA
| | - Nicolás B. Gómez
- Department of Neurology
- Cellular and Molecular Biology Program, Michigan Medicine, University of Michigan, Ann Arbor, Michigan, USA
| | | | - Ziqiang Lin
- Department of Basic and Clinical Neuroscience and
| | - Carmen Moreno Gonzalez
- Centre for Craniofacial and Regenerative Biology, King’s College London, London, United Kingdom
| | - Andrea Serio
- Centre for Craniofacial and Regenerative Biology, King’s College London, London, United Kingdom
| | | | - Sami J. Barmada
- Department of Neurology
- Neuroscience Graduate Program, and
- Cellular and Molecular Biology Program, Michigan Medicine, University of Michigan, Ann Arbor, Michigan, USA
| |
Collapse
|
36
|
Spadotto V, Giambruno R, Massignani E, Mihailovich M, Maniaci M, Patuzzo F, Ghini F, Nicassio F, Bonaldi T. PRMT1-mediated methylation of the microprocessor-associated proteins regulates microRNA biogenesis. Nucleic Acids Res 2020; 48:96-115. [PMID: 31777917 PMCID: PMC6943135 DOI: 10.1093/nar/gkz1051] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Revised: 10/04/2019] [Accepted: 11/22/2019] [Indexed: 12/17/2022] Open
Abstract
MicroRNA (miRNA) biogenesis is a tightly controlled multi-step process operated in the nucleus by the activity of the Microprocessor and its associated proteins. Through high resolution mass spectrometry (MS)- proteomics we discovered that this complex is extensively methylated, with 84 methylated sites associated to 19 out of its 24 subunits. The majority of the modifications occurs on arginine (R) residues (61), leading to 81 methylation events, while 30 lysine (K)-methylation events occurs on 23 sites of the complex. Interestingly, both depletion and pharmacological inhibition of the Type-I Protein Arginine Methyltransferases (PRMTs) lead to a widespread change in the methylation state of the complex and induce global decrease of miRNA expression, as a consequence of the impairment of the pri-to-pre-miRNA processing step. In particular, we show that the reduced methylation of the Microprocessor subunit ILF3 is linked to its diminished binding to the pri-miRNAs miR-15a/16, miR-17-92, miR-301a and miR-331. Our study uncovers a previously uncharacterized role of R-methylation in the regulation of miRNA biogenesis in mammalian cells.
Collapse
Affiliation(s)
- Valeria Spadotto
- Department of Experimental Oncology, IEO, European Institute of Oncology IRCCS, Milan, Italy
| | - Roberto Giambruno
- Department of Experimental Oncology, IEO, European Institute of Oncology IRCCS, Milan, Italy
| | - Enrico Massignani
- Department of Experimental Oncology, IEO, European Institute of Oncology IRCCS, Milan, Italy
| | - Marija Mihailovich
- Department of Experimental Oncology, IEO, European Institute of Oncology IRCCS, Milan, Italy
| | - Marianna Maniaci
- Department of Experimental Oncology, IEO, European Institute of Oncology IRCCS, Milan, Italy
| | - Francesca Patuzzo
- Department of Experimental Oncology, IEO, European Institute of Oncology IRCCS, Milan, Italy
| | - Francesco Ghini
- Center for Genomic Science of IIT@SEMM, Istituto Italiano di Tecnologia, Milan, Italy
| | - Francesco Nicassio
- Center for Genomic Science of IIT@SEMM, Istituto Italiano di Tecnologia, Milan, Italy
| | - Tiziana Bonaldi
- Department of Experimental Oncology, IEO, European Institute of Oncology IRCCS, Milan, Italy
| |
Collapse
|
37
|
Germeys C, Vandoorne T, Bercier V, Van Den Bosch L. Existing and Emerging Metabolomic Tools for ALS Research. Genes (Basel) 2019; 10:E1011. [PMID: 31817338 PMCID: PMC6947647 DOI: 10.3390/genes10121011] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Revised: 11/23/2019] [Accepted: 12/03/2019] [Indexed: 12/12/2022] Open
Abstract
Growing evidence suggests that aberrant energy metabolism could play an important role in the pathogenesis of amyotrophic lateral sclerosis (ALS). Despite this, studies applying advanced technologies to investigate energy metabolism in ALS remain scarce. The rapidly growing field of metabolomics offers exciting new possibilities for ALS research. Here, we review existing and emerging metabolomic tools that could be used to further investigate the role of metabolism in ALS. A better understanding of the metabolic state of motor neurons and their surrounding cells could hopefully result in novel therapeutic strategies.
Collapse
Affiliation(s)
- Christine Germeys
- Department of Neurosciences, Experimental Neurology, and Leuven Brain Institute (LBI), KU Leuven—University of Leuven, 3000 Leuven, Belgium; (C.G.); (T.V.); (V.B.)
- VIB, Center for Brain & Disease Research, Laboratory of Neurobiology, 3000 Leuven, Belgium
| | - Tijs Vandoorne
- Department of Neurosciences, Experimental Neurology, and Leuven Brain Institute (LBI), KU Leuven—University of Leuven, 3000 Leuven, Belgium; (C.G.); (T.V.); (V.B.)
- VIB, Center for Brain & Disease Research, Laboratory of Neurobiology, 3000 Leuven, Belgium
| | - Valérie Bercier
- Department of Neurosciences, Experimental Neurology, and Leuven Brain Institute (LBI), KU Leuven—University of Leuven, 3000 Leuven, Belgium; (C.G.); (T.V.); (V.B.)
- VIB, Center for Brain & Disease Research, Laboratory of Neurobiology, 3000 Leuven, Belgium
| | - Ludo Van Den Bosch
- Department of Neurosciences, Experimental Neurology, and Leuven Brain Institute (LBI), KU Leuven—University of Leuven, 3000 Leuven, Belgium; (C.G.); (T.V.); (V.B.)
- VIB, Center for Brain & Disease Research, Laboratory of Neurobiology, 3000 Leuven, Belgium
| |
Collapse
|
38
|
The Acetylation of Lysine-376 of G3BP1 Regulates RNA Binding and Stress Granule Dynamics. Mol Cell Biol 2019; 39:MCB.00052-19. [PMID: 31481451 DOI: 10.1128/mcb.00052-19] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Accepted: 08/29/2019] [Indexed: 01/11/2023] Open
Abstract
Stress granules (SGs) are ribonucleoprotein aggregates that form in response to stress conditions. The regulation of SG dynamics is not fully understood. Permanent pathological SG-like structures were reported in neurodegenerative diseases such as amyotrophic lateral sclerosis. The Ras GTPase-activating protein-binding protein G3BP1 is a central regulator of SG dynamics. We found that the lysine 376 residue (K376) of G3BP1, which is in the RRM RNA binding domain, was acetylated. Consequently, G3BP1 RNA binding was impaired by K376 acetylation. In addition, the acetylation-mimicking mutation K376Q impaired the RNA-dependent interaction of G3BP1 with poly(A)-binding protein 1 (PABP1), but its RNA-independent interactions with caprin-1 and USP10 were little affected. The formation of G3BP1 SGs depended on G3BP1 RNA binding; thus, replacement of endogenous G3BP1 with the K376Q mutant or the RNA binding-deficient F380L/F382L mutant interfered with SG formation. Significant G3BP1 K376 acetylation was detected during SG resolution, and K376-acetylated G3BP1 was seen outside SGs. G3BP1 acetylation is regulated by histone deacetylase 6 (HDAC6) and CBP/p300. Our data suggest that the acetylation of G3BP1 facilitates the disassembly of SGs, offering a potential avenue to mitigate hyperactive stress responses under pathological conditions.
Collapse
|
39
|
Galves M, Rathi R, Prag G, Ashkenazi A. Ubiquitin Signaling and Degradation of Aggregate-Prone Proteins. Trends Biochem Sci 2019; 44:872-884. [DOI: 10.1016/j.tibs.2019.04.007] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2019] [Revised: 04/08/2019] [Accepted: 04/11/2019] [Indexed: 12/30/2022]
|
40
|
Ma L, Herren AW, Espinal G, Randol J, McLaughlin B, Martinez-Cerdeño V, Pessah IN, Hagerman RJ, Hagerman PJ. Composition of the Intranuclear Inclusions of Fragile X-associated Tremor/Ataxia Syndrome. Acta Neuropathol Commun 2019; 7:143. [PMID: 31481131 PMCID: PMC6720097 DOI: 10.1186/s40478-019-0796-1] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Accepted: 08/24/2019] [Indexed: 12/11/2022] Open
Abstract
Fragile X-associated tremor/ataxia syndrome (FXTAS) is a neurodegenerative disorder associated with a premutation repeat expansion (55-200 CGG repeats) in the 5' noncoding region of the FMR1 gene. Solitary intranuclear inclusions within FXTAS neurons and astrocytes constitute a hallmark of the disorder, yet our understanding of how and why these bodies form is limited. Here, we have discovered that FXTAS inclusions emit a distinct autofluorescence spectrum, which forms the basis of a novel, unbiased method for isolating FXTAS inclusions by preparative fluorescence-activated cell sorting (FACS). Using a combination of autofluorescence-based FACS and liquid chromatography/tandem mass spectrometry (LC-MS/MS)-based proteomics, we have identified more than two hundred proteins that are enriched within the inclusions relative to FXTAS whole nuclei. Whereas no single protein species dominates inclusion composition, highly enriched levels of conjugated small ubiquitin-related modifier 2 (SUMO 2) protein and p62/sequestosome-1 (p62/SQSTM1) protein were found within the inclusions. Many additional proteins involved with RNA binding, protein turnover, and DNA damage repair were enriched within inclusions relative to total nuclear protein. The current analysis has also allowed the first direct detection, through peptide sequencing, of endogenous FMRpolyG peptide, the product of repeat-associated non-ATG (RAN) translation of the FMR1 mRNA. However, this peptide was found only at extremely low levels and not within whole FXTAS nuclear preparations, raising the question whether endogenous RAN products exist at quantities sufficient to contribute to FXTAS pathogenesis. The abundance of the inclusion-associated ubiquitin- and SUMO-based modifiers supports a model for inclusion formation as the result of increased protein loads and elevated oxidative stress leading to maladaptive autophagy. These results highlight the need to further investigate FXTAS pathogenesis in the context of endogenous systems.
Collapse
Affiliation(s)
- Lisa Ma
- Department of Biochemistry and Molecular Medicine, University of California Davis, School of Medicine, One Shields Ave, Davis, CA, USA
| | - Anthony W Herren
- Genome Center, University of California Davis, Davis, California, USA
| | - Glenda Espinal
- Department of Biochemistry and Molecular Medicine, University of California Davis, School of Medicine, One Shields Ave, Davis, CA, USA
| | - Jamie Randol
- Department of Biochemistry and Molecular Medicine, University of California Davis, School of Medicine, One Shields Ave, Davis, CA, USA
| | - Bridget McLaughlin
- Department of Pathology and Laboratory Medicine, University of California Davis, School of Medicine, Sacramento, California, USA
| | - Veronica Martinez-Cerdeño
- Department of Pathology and Laboratory Medicine, University of California Davis, School of Medicine, Sacramento, California, USA
- Institute for Pediatric Regenerative Medicine, Shriners Hospital of Northern California, University of California Davis, School of Medicine, Sacramento, California, USA
- MIND Institute, University of California Davis Health, Sacramento, California, USA
| | - Isaac N Pessah
- MIND Institute, University of California Davis Health, Sacramento, California, USA
- Department of Molecular Biosciences, University of California Davis, School of Veterinary Medicine, Davis, California, USA
| | - Randi J Hagerman
- MIND Institute, University of California Davis Health, Sacramento, California, USA
- Department of Pediatrics, University of California Davis, School of Medicine, Sacramento, California, USA
| | - Paul J Hagerman
- Department of Biochemistry and Molecular Medicine, University of California Davis, School of Medicine, One Shields Ave, Davis, CA, USA.
- MIND Institute, University of California Davis Health, Sacramento, California, USA.
| |
Collapse
|
41
|
Cobos SN, Bennett SA, Torrente MP. The impact of histone post-translational modifications in neurodegenerative diseases. Biochim Biophys Acta Mol Basis Dis 2019; 1865:1982-1991. [PMID: 30352259 PMCID: PMC6475498 DOI: 10.1016/j.bbadis.2018.10.019] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Revised: 10/05/2018] [Accepted: 10/11/2018] [Indexed: 02/08/2023]
Abstract
Every year, neurodegenerative disorders take more than 5000 lives in the US alone. Cures have not yet been found for many of the multitude of neuropathies. The majority of amyotrophic lateral sclerosis (ALS), frontotemporal dementia (FTD) and Parkinson's disease (PD) cases have no known genetic basis. Thus, it is evident that contemporary genetic approaches have failed to explain the etiology or etiologies of ALS/FTD and PD. Recent investigations have explored the potential role of epigenetic mechanisms in disease development. Epigenetics comprises heritable changes in gene utilization that are not derived from changes in the genome. A main epigenetic mechanism involves the post-translational modification of histones. Increased knowledge of the epigenomic landscape of neurodegenerative diseases would not only further our understanding of the disease pathologies, but also lead to the development of treatments able to halt their progress. Here, we review recent advances on the association of histone post-translational modifications with ALS, FTD, PD and several ataxias.
Collapse
Affiliation(s)
- Samantha N Cobos
- Chemistry Department of Brooklyn College, Brooklyn, New York 11210, United States; Ph.D. Program in Chemistry, The Graduate Center of the City University of New York, New York, NY 10016, United States
| | - Seth A Bennett
- Chemistry Department of Brooklyn College, Brooklyn, New York 11210, United States; Ph.D. Program in Biochemistry, The Graduate Center of the City University of New York, New York, NY 10016, United States
| | - Mariana P Torrente
- Chemistry Department of Brooklyn College, Brooklyn, New York 11210, United States; Ph.D. Programs in Chemistry, Biochemistry, and Biology, The Graduate Center of the City University of New York, New York 10016, United States.
| |
Collapse
|
42
|
Lorton BM, Shechter D. Cellular consequences of arginine methylation. Cell Mol Life Sci 2019; 76:2933-2956. [PMID: 31101937 PMCID: PMC6642692 DOI: 10.1007/s00018-019-03140-2] [Citation(s) in RCA: 91] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Revised: 04/22/2019] [Accepted: 05/10/2019] [Indexed: 02/07/2023]
Abstract
Arginine methylation is a ubiquitous post-translational modification. Three predominant types of arginine-guanidino methylation occur in Eukarya: mono (Rme1/MMA), symmetric (Rme2s/SDMA), and asymmetric (Rme2a/ADMA). Arginine methylation frequently occurs at sites of protein-protein and protein-nucleic acid interactions, providing specificity for binding partners and stabilization of important biological interactions in diverse cellular processes. Each methylarginine isoform-catalyzed by members of the protein arginine methyltransferase family, Type I (PRMT1-4,6,8) and Type II (PRMT5,9)-has unique downstream consequences. Methylarginines are found in ordered domains, domains of low complexity, and in intrinsically disordered regions of proteins-the latter two of which are intimately connected with biological liquid-liquid phase separation. This review highlights discoveries illuminating how arginine methylation affects genome integrity, gene transcription, mRNA splicing and mRNP biology, protein translation and stability, and phase separation. As more proteins and processes are found to be regulated by arginine methylation, its importance for understanding cellular physiology will continue to grow.
Collapse
Affiliation(s)
- Benjamin M Lorton
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
| | - David Shechter
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY, 10461, USA.
| |
Collapse
|
43
|
Hedl TJ, San Gil R, Cheng F, Rayner SL, Davidson JM, De Luca A, Villalva MD, Ecroyd H, Walker AK, Lee A. Proteomics Approaches for Biomarker and Drug Target Discovery in ALS and FTD. Front Neurosci 2019; 13:548. [PMID: 31244593 PMCID: PMC6579929 DOI: 10.3389/fnins.2019.00548] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Accepted: 05/13/2019] [Indexed: 12/11/2022] Open
Abstract
Neurodegenerative disorders such as amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) are increasing in prevalence but lack targeted therapeutics. Although the pathological mechanisms behind these diseases remain unclear, both ALS and FTD are characterized pathologically by aberrant protein aggregation and inclusion formation within neurons, which correlates with neurodegeneration. Notably, aggregation of several key proteins, including TAR DNA binding protein of 43 kDa (TDP-43), superoxide dismutase 1 (SOD1), and tau, have been implicated in these diseases. Proteomics methods are being increasingly applied to better understand disease-related mechanisms and to identify biomarkers of disease, using model systems as well as human samples. Proteomics-based approaches offer unbiased, high-throughput, and quantitative results with numerous applications for investigating proteins of interest. Here, we review recent advances in the understanding of ALS and FTD pathophysiology obtained using proteomics approaches, and we assess technical and experimental limitations. We compare findings from various mass spectrometry (MS) approaches including quantitative proteomics methods such as stable isotope labeling by amino acids in cell culture (SILAC) and tandem mass tagging (TMT) to approaches such as label-free quantitation (LFQ) and sequential windowed acquisition of all theoretical fragment ion mass spectra (SWATH-MS) in studies of ALS and FTD. Similarly, we describe disease-related protein-protein interaction (PPI) studies using approaches including immunoprecipitation mass spectrometry (IP-MS) and proximity-dependent biotin identification (BioID) and discuss future application of new techniques including proximity-dependent ascorbic acid peroxidase labeling (APEX), and biotinylation by antibody recognition (BAR). Furthermore, we explore the use of MS to detect post-translational modifications (PTMs), such as ubiquitination and phosphorylation, of disease-relevant proteins in ALS and FTD. We also discuss upstream technologies that enable enrichment of proteins of interest, highlighting the contributions of new techniques to isolate disease-relevant protein inclusions including flow cytometric analysis of inclusions and trafficking (FloIT). These recently developed approaches, as well as related advances yet to be applied to studies of these neurodegenerative diseases, offer numerous opportunities for discovery of potential therapeutic targets and biomarkers for ALS and FTD.
Collapse
Affiliation(s)
- Thomas J Hedl
- Neurodegeneration Pathobiology Laboratory, Queensland Brain Institute, The University of Queensland, St Lucia, QLD, Australia
| | - Rebecca San Gil
- Neurodegeneration Pathobiology Laboratory, Queensland Brain Institute, The University of Queensland, St Lucia, QLD, Australia
| | - Flora Cheng
- Centre for Motor Neuron Disease Research, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, North Ryde, NSW, Australia
| | - Stephanie L Rayner
- Centre for Motor Neuron Disease Research, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, North Ryde, NSW, Australia
| | - Jennilee M Davidson
- Centre for Motor Neuron Disease Research, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, North Ryde, NSW, Australia
| | - Alana De Luca
- Centre for Motor Neuron Disease Research, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, North Ryde, NSW, Australia
| | - Maria D Villalva
- Centre for Motor Neuron Disease Research, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, North Ryde, NSW, Australia
| | - Heath Ecroyd
- School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW, Australia.,Illawarra Health and Medical Research Institute, Wollongong, NSW, Australia
| | - Adam K Walker
- Neurodegeneration Pathobiology Laboratory, Queensland Brain Institute, The University of Queensland, St Lucia, QLD, Australia.,Centre for Motor Neuron Disease Research, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, North Ryde, NSW, Australia
| | - Albert Lee
- Centre for Motor Neuron Disease Research, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, North Ryde, NSW, Australia
| |
Collapse
|
44
|
Verdile V, De Paola E, Paronetto MP. Aberrant Phase Transitions: Side Effects and Novel Therapeutic Strategies in Human Disease. Front Genet 2019; 10:173. [PMID: 30967892 PMCID: PMC6440380 DOI: 10.3389/fgene.2019.00173] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Accepted: 02/18/2019] [Indexed: 12/12/2022] Open
Abstract
Phase separation is a physiological process occurring spontaneously when single-phase molecular complexes separate in two phases, a concentrated phase and a more diluted one. Eukaryotic cells employ phase transition strategies to promote the formation of intracellular territories not delimited by membranes with increased local RNA concentration, such as nucleolus, paraspeckles, P granules, Cajal bodies, P-bodies, and stress granules. These organelles contain both proteins and coding and non-coding RNAs and play important roles in different steps of the regulation of gene expression and in cellular signaling. Recently, it has been shown that most human RNA-binding proteins (RBPs) contain at least one low-complexity domain, called prion-like domain (PrLD), because proteins harboring them display aggregation properties like prion proteins. PrLDs support RBP function and contribute to liquid–liquid phase transitions that drive ribonucleoprotein granule assembly, but also render RBPs prone to misfolding by promoting the formation of pathological aggregates that lead to toxicity in specific cell types. Protein–protein and protein-RNA interactions within the separated phase can enhance the transition of RBPs into solid aberrant aggregates, thus causing diseases. In this review, we highlight the role of phase transition in human disease such as amyotrophic lateral sclerosis (ALS), frontotemporal dementia (FTD), and in cancer. Moreover, we discuss novel therapeutic strategies focused to control phase transitions by preventing the conversion into aberrant aggregates. In this regard, the stimulation of chaperone machinery to disassemble membrane-less organelles, the induction of pathways that could inhibit aberrant phase separation, and the development of antisense oligonucleotides (ASOs) to knockdown RNAs could be evaluated as novel therapeutic strategies for the treatment of those human diseases characterized by aberrant phase transition aggregates.
Collapse
Affiliation(s)
- Veronica Verdile
- University of Rome "Foro Italico", Rome, Italy.,Laboratory of Cellular and Molecular Neurobiology, Fondazione Santa Lucia, Rome, Italy
| | - Elisa De Paola
- University of Rome "Foro Italico", Rome, Italy.,Laboratory of Cellular and Molecular Neurobiology, Fondazione Santa Lucia, Rome, Italy
| | - Maria Paola Paronetto
- University of Rome "Foro Italico", Rome, Italy.,Laboratory of Cellular and Molecular Neurobiology, Fondazione Santa Lucia, Rome, Italy
| |
Collapse
|
45
|
Prasad A, Bharathi V, Sivalingam V, Girdhar A, Patel BK. Molecular Mechanisms of TDP-43 Misfolding and Pathology in Amyotrophic Lateral Sclerosis. Front Mol Neurosci 2019; 12:25. [PMID: 30837838 PMCID: PMC6382748 DOI: 10.3389/fnmol.2019.00025] [Citation(s) in RCA: 407] [Impact Index Per Article: 81.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Accepted: 01/21/2019] [Indexed: 12/11/2022] Open
Abstract
TAR DNA binding protein 43 (TDP-43) is a versatile RNA/DNA binding protein involved in RNA-related metabolism. Hyper-phosphorylated and ubiquitinated TDP-43 deposits act as inclusion bodies in the brain and spinal cord of patients with the motor neuron diseases: amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD). While the majority of ALS cases (90-95%) are sporadic (sALS), among familial ALS cases 5-10% involve the inheritance of mutations in the TARDBP gene and the remaining (90-95%) are due to mutations in other genes such as: C9ORF72, SOD1, FUS, and NEK1 etc. Strikingly however, the majority of sporadic ALS patients (up to 97%) also contain the TDP-43 protein deposited in the neuronal inclusions, which suggests of its pivotal role in the ALS pathology. Thus, unraveling the molecular mechanisms of the TDP-43 pathology seems central to the ALS therapeutics, hence, we comprehensively review the current understanding of the TDP-43's pathology in ALS. We discuss the roles of TDP-43's mutations, its cytoplasmic mis-localization and aberrant post-translational modifications in ALS. Also, we evaluate TDP-43's amyloid-like in vitro aggregation, its physiological vs. pathological oligomerization in vivo, liquid-liquid phase separation (LLPS), and potential prion-like propagation propensity of the TDP-43 inclusions. Finally, we describe the various evolving TDP-43-induced toxicity mechanisms, such as the impairment of endocytosis and mitotoxicity etc. and also discuss the emerging strategies toward TDP-43 disaggregation and ALS therapeutics.
Collapse
Affiliation(s)
| | | | | | | | - Basant K. Patel
- Department of Biotechnology, Indian Institute of Technology Hyderabad, Sangareddy, India
| |
Collapse
|
46
|
Duan Y, Du A, Gu J, Duan G, Wang C, Gui X, Ma Z, Qian B, Deng X, Zhang K, Sun L, Tian K, Zhang Y, Jiang H, Liu C, Fang Y. PARylation regulates stress granule dynamics, phase separation, and neurotoxicity of disease-related RNA-binding proteins. Cell Res 2019; 29:233-247. [PMID: 30728452 DOI: 10.1038/s41422-019-0141-z] [Citation(s) in RCA: 168] [Impact Index Per Article: 33.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Accepted: 01/07/2019] [Indexed: 01/07/2023] Open
Abstract
Mutations in RNA-binding proteins (RBPs) localized in ribonucleoprotein (RNP) granules, such as hnRNP A1 and TDP-43, promote aberrant protein aggregation, which is a pathological hallmark of various neurodegenerative diseases, such as amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Protein posttranslational modifications (PTMs) are known to regulate RNP granules. In this study, we investigate the function of poly(ADP-ribosyl)ation (PARylation), an important PTM involved in DNA damage repair and cell death, in RNP granule-related neurodegeneration. We reveal that PARylation levels are a major regulator of the assembly-disassembly dynamics of RNP granules containing disease-related RBPs, hnRNP A1 and TDP-43. We find that hnRNP A1 can both be PARylated and bind to PARylated proteins or poly(ADP-ribose) (PAR). We further uncover that PARylation of hnRNP A1 at K298 controls its nucleocytoplasmic transport, whereas PAR-binding via the PAR-binding motif (PBM) of hnRNP A1 regulates its association with stress granules. Moreover, we reveal that PAR not only dramatically enhances the liquid-liquid phase separation of hnRNP A1, but also promotes the co-phase separation of hnRNP A1 and TDP-43 in vitro and their interaction in vivo. Finally, both genetic and pharmacological inhibition of PARP mitigates hnRNP A1- and TDP-43-mediated neurotoxicity in cell and Drosophila models of ALS. Together, our findings suggest a novel and crucial role for PARylation in regulating the dynamics of RNP granules, and that dysregulation in PARylation and PAR levels may contribute to ALS disease pathogenesis by promoting protein aggregation.
Collapse
Affiliation(s)
- Yongjia Duan
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, 201210, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Aiying Du
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, 201210, China
| | - Jinge Gu
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, 201210, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Gang Duan
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, 201210, China
| | - Chen Wang
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, 201210, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xinrui Gui
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, 201210, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Zhiwei Ma
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, 201210, China.,Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Beituo Qian
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, 201210, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xue Deng
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, 201210, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Kai Zhang
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, 201210, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Le Sun
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, 201210, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Kuili Tian
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, 201210, China
| | - Yaoyang Zhang
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, 201210, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Hong Jiang
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, 201210, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Cong Liu
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, 201210, China. .,University of Chinese Academy of Sciences, Beijing, 100049, China.
| | - Yanshan Fang
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, 201210, China. .,University of Chinese Academy of Sciences, Beijing, 100049, China.
| |
Collapse
|
47
|
Abreha MH, Dammer EB, Ping L, Zhang T, Duong DM, Gearing M, Lah JJ, Levey AI, Seyfried NT. Quantitative Analysis of the Brain Ubiquitylome in Alzheimer's Disease. Proteomics 2018; 18:e1800108. [PMID: 30230243 PMCID: PMC6283072 DOI: 10.1002/pmic.201800108] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Revised: 08/16/2018] [Indexed: 12/15/2022]
Abstract
Several neurodegenerative diseases including Alzheimer's Disease (AD) are characterized by ubiquitin-positive pathological protein aggregates. Here, an immunoaffinity approach is utilized to enrich ubiquitylated isopeptides after trypsin digestion from five AD and five age-matched control postmortem brain tissues. Label-free MS-based proteomic analysis identifies 4291 unique ubiquitylation sites mapping to 1682 unique proteins. Differential enrichment analysis shows that over 800 ubiquitylation sites are significantly altered between AD and control cases. Of these, ≈80% are increased in AD, including seven poly ubiquitin linkages, which is consistent with proteolytic stress and high burden of ubiquitylated pathological aggregates in AD. The microtubule associated protein Tau, the core component of neurofibrillary tangles, has the highest number of increased sites of ubiquitylation per any protein in AD. Tau poly ubiquitylation from AD brain homogenates is confirmed by reciprocal co-immunoprecipitation and by affinity capture using tandem ubiquitin binding entities. Co-modified peptides, with both ubiquitylation and phosphorylation sites, are also enriched in AD. Notably, many of the co-modified peptides mapped to Tau within KXGS motifs in the microtubule binding region suggesting that crosstalk between phosphorylation and ubiquitylation occurs on Tau in AD. Overall, these findings highlight the utility of MS to map ubiquitylated substrates in human brain and provides insight into mechanisms underlying pathological protein posttranslational modification in AD.
Collapse
Affiliation(s)
- Measho H. Abreha
- Center for Neurodegenerative Diseases, Emory University
School of Medicine, Atlanta, GA, 30322
| | - Eric B. Dammer
- Department of Biochemistry, Emory University School of
Medicine, Atlanta, GA, 30322
- Center for Neurodegenerative Diseases, Emory University
School of Medicine, Atlanta, GA, 30322
| | - Lingyan Ping
- Department of Biochemistry, Emory University School of
Medicine, Atlanta, GA, 30322
- Center for Neurodegenerative Diseases, Emory University
School of Medicine, Atlanta, GA, 30322
| | - Tian Zhang
- Department of Biochemistry, Emory University School of
Medicine, Atlanta, GA, 30322
- Center for Neurodegenerative Diseases, Emory University
School of Medicine, Atlanta, GA, 30322
| | - Duc M. Duong
- Department of Biochemistry, Emory University School of
Medicine, Atlanta, GA, 30322
- Center for Neurodegenerative Diseases, Emory University
School of Medicine, Atlanta, GA, 30322
| | - Marla Gearing
- Department of Pathology and Laboratory Medicine, Emory
University School of Medicine, Atlanta, GA, 30322
- Center for Neurodegenerative Diseases, Emory University
School of Medicine, Atlanta, GA, 30322
| | - James J. Lah
- Department of Neurology, Emory University School of
Medicine, Atlanta, GA, 30322
- Center for Neurodegenerative Diseases, Emory University
School of Medicine, Atlanta, GA, 30322
| | - Allan I. Levey
- Department of Neurology, Emory University School of
Medicine, Atlanta, GA, 30322
- Center for Neurodegenerative Diseases, Emory University
School of Medicine, Atlanta, GA, 30322
| | - Nicholas T. Seyfried
- Department of Biochemistry, Emory University School of
Medicine, Atlanta, GA, 30322
- Department of Neurology, Emory University School of
Medicine, Atlanta, GA, 30322
- Center for Neurodegenerative Diseases, Emory University
School of Medicine, Atlanta, GA, 30322
| |
Collapse
|
48
|
Hans F, Eckert M, von Zweydorf F, Gloeckner CJ, Kahle PJ. Identification and characterization of ubiquitinylation sites in TAR DNA-binding protein of 43 kDa (TDP-43). J Biol Chem 2018; 293:16083-16099. [PMID: 30120199 DOI: 10.1074/jbc.ra118.003440] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Revised: 08/14/2018] [Indexed: 12/13/2022] Open
Abstract
TAR DNA-binding protein of 43 kDa (TDP-43) forms pathological aggregates in neurodegenerative diseases, particularly in certain forms of frontotemporal dementia and amyotrophic lateral sclerosis. Pathological modifications of TDP-43 include proteolytic fragmentation, phosphorylation, and ubiquitinylation. A pathognomonic TDP-43 C-terminal fragment (CTF) spanning amino acids 193-414 contains only four lysine residues that could be potentially ubiquitinylated. Here, serial mutagenesis of these four lysines to arginine revealed that not a single residue is responsible for the ubiquitinylation of mCherry-tagged CTF. Removal of all four lysines was necessary to suppress ubiquitinylation. Interestingly, Lys-408 substitution enhanced the pathological phosphorylation of the immediately adjacent serine residues 409/410 in the context of mCherry-CTF. Thus, Lys-408 ubiquitinylation appears to hinder Ser-409/410 phosphorylation in TDP-43 CTF. However, we did not observe the same effect for full-length TDP-43. We extended the mutagenesis study to full-length TDP-43 and performed MS. Ubiquitinylated lysine residues were identified in the nuclear localization sequence (NLS; Lys-84 and Lys-95) and RNA-binding region (mostly Lys-160, Lys-181, and Lys-263). Mutagenesis of Lys-84 confirmed its importance as the major determinant for nuclear import, whereas Lys-95 mutagenesis did not significantly affect TDP-43's nucleo-cytoplasmic distribution, solubility, aggregation, and RNA-processing activities. Nevertheless, the K95A mutant had significantly reduced Ser-409/410 phosphorylation, emphasizing the suspected interplay between TDP-43 ubiquitinylation and phosphorylation. Collectively, our analysis of TDP-43 ubiquitinylation sites indicates that the NLS residues Lys-84 and Lys-95 have more prominent roles in TDP-43 function than the more C-terminal lysines and suggests a link between specific ubiquitinylation events and pathological TDP-43 phosphorylation.
Collapse
Affiliation(s)
- Friederike Hans
- From the German Center for Neurodegenerative Diseases (DZNE), 72076 Tübingen and.,the Hertie Institute for Clinical Brain Research, Department of Neurodegeneration, and
| | - Marita Eckert
- From the German Center for Neurodegenerative Diseases (DZNE), 72076 Tübingen and.,the Hertie Institute for Clinical Brain Research, Department of Neurodegeneration, and
| | - Felix von Zweydorf
- From the German Center for Neurodegenerative Diseases (DZNE), 72076 Tübingen and
| | - Christian Johannes Gloeckner
- From the German Center for Neurodegenerative Diseases (DZNE), 72076 Tübingen and.,the Institute for Ophthalmic Research, Center for Ophthalmology, University of Tübingen, 72076 Tübingen, Germany
| | - Philipp J Kahle
- From the German Center for Neurodegenerative Diseases (DZNE), 72076 Tübingen and .,the Hertie Institute for Clinical Brain Research, Department of Neurodegeneration, and
| |
Collapse
|
49
|
Bishof I, Dammer EB, Duong DM, Kundinger SR, Gearing M, Lah JJ, Levey AI, Seyfried NT. RNA-binding proteins with basic-acidic dipeptide (BAD) domains self-assemble and aggregate in Alzheimer's disease. J Biol Chem 2018; 293:11047-11066. [PMID: 29802200 PMCID: PMC6052236 DOI: 10.1074/jbc.ra118.001747] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Revised: 05/23/2018] [Indexed: 12/12/2022] Open
Abstract
The U1 small nuclear ribonucleoprotein 70 kDa (U1-70K) and other RNA-binding proteins (RBPs) are mislocalized to cytoplasmic neurofibrillary Tau aggregates in Alzheimer's disease (AD), yet the co-aggregation mechanisms are incompletely understood. U1-70K harbors two disordered low-complexity domains (LC1 and LC2) that are necessary for aggregation in AD brain extracts. The LC1 domain contains highly repetitive basic (Arg/Lys) and acidic (Asp/Glu) residues, referred to as a basic-acidic dipeptide (BAD) domain. We report here that this domain shares many of the properties of the Gln/Asn-rich LC domains in RBPs that also aggregate in neurodegenerative disease. These properties included self-assembly into oligomers and localization to nuclear granules. Co-immunoprecipitations of recombinant U1-70K and deletions lacking the LC domain(s) followed by quantitative proteomic analyses were used to resolve functional classes of U1-70K-interacting proteins that depend on the BAD domain for their interaction. Within this interaction network, we identified a class of RBPs with BAD domains nearly identical to that found in U1-70K. Two members of this class, LUC7L3 and RBM25, required their respective BAD domains for reciprocal interactions with U1-70K and nuclear granule localization. Strikingly, a significant proportion of RBPs with BAD domains had elevated insolubility in the AD brain proteome. Furthermore, we show that the BAD domain of U1-70K can interact with Tau from AD brains but not from other tauopathies. These findings highlight a mechanistic role for BAD domains in stabilizing RBP interactions and in potentially mediating co-aggregation with the pathological AD-specific Tau isoforms.
Collapse
Affiliation(s)
- Isaac Bishof
- From the Departments of Biochemistry
- the Center for Neurodegenerative Diseases, Emory University School of Medicine, Atlanta, Georgia 30322
| | - Eric B Dammer
- From the Departments of Biochemistry
- the Center for Neurodegenerative Diseases, Emory University School of Medicine, Atlanta, Georgia 30322
| | - Duc M Duong
- From the Departments of Biochemistry
- the Center for Neurodegenerative Diseases, Emory University School of Medicine, Atlanta, Georgia 30322
| | - Sean R Kundinger
- From the Departments of Biochemistry
- the Center for Neurodegenerative Diseases, Emory University School of Medicine, Atlanta, Georgia 30322
| | - Marla Gearing
- the Center for Neurodegenerative Diseases, Emory University School of Medicine, Atlanta, Georgia 30322
- Pathology and Laboratory Medicine and
| | - James J Lah
- the Center for Neurodegenerative Diseases, Emory University School of Medicine, Atlanta, Georgia 30322
- Neurology, and
| | - Allan I Levey
- the Center for Neurodegenerative Diseases, Emory University School of Medicine, Atlanta, Georgia 30322
- Neurology, and
| | - Nicholas T Seyfried
- From the Departments of Biochemistry,
- the Center for Neurodegenerative Diseases, Emory University School of Medicine, Atlanta, Georgia 30322
- Neurology, and
| |
Collapse
|
50
|
Cox D, Raeburn C, Sui X, Hatters DM. Protein aggregation in cell biology: An aggregomics perspective of health and disease. Semin Cell Dev Biol 2018; 99:40-54. [PMID: 29753879 DOI: 10.1016/j.semcdb.2018.05.003] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Revised: 03/21/2018] [Accepted: 05/04/2018] [Indexed: 01/08/2023]
Abstract
Maintaining protein homeostasis (proteostasis) is essential for cellular health and is governed by a network of quality control machinery comprising over 800 genes. When proteostasis becomes imbalanced, proteins can abnormally aggregate or become mislocalized. Inappropriate protein aggregation and proteostasis imbalance are two of the central pathological features of common neurodegenerative diseases including Alzheimer, Parkinson, Huntington, and motor neuron diseases. How aggregation contributes to the pathogenic mechanisms of disease remains incompletely understood. Here, we integrate some of the key and emerging ideas as to how protein aggregation relates to imbalanced proteostasis with an emphasis on Huntington disease as our area of main expertise. We propose the term "aggregomics" be coined in reference to how aggregation of particular proteins concomitantly influences the spatial organization and protein-protein interactions of the surrounding proteome. Meta-analysis of aggregated interactomes from various published datasets reveals chaperones and RNA-binding proteins are common components across various disease contexts. We conclude with an examination of therapeutic avenues targeting proteostasis mechanisms.
Collapse
Affiliation(s)
- Dezerae Cox
- Department of Biochemistry and Molecular Biology, The University of Melbourne, Australia; Bio21 Molecular Science and Biotechnology Institute, Australia
| | - Candice Raeburn
- Department of Biochemistry and Molecular Biology, The University of Melbourne, Australia; Bio21 Molecular Science and Biotechnology Institute, Australia
| | - Xiaojing Sui
- Department of Biochemistry and Molecular Biology, The University of Melbourne, Australia; Bio21 Molecular Science and Biotechnology Institute, Australia
| | - Danny M Hatters
- Department of Biochemistry and Molecular Biology, The University of Melbourne, Australia; Bio21 Molecular Science and Biotechnology Institute, Australia.
| |
Collapse
|