1
|
Song J. Molecular Mechanisms of Phase Separation and Amyloidosis of ALS/FTD-linked FUS and TDP-43. Aging Dis 2024; 15:2084-2112. [PMID: 38029395 PMCID: PMC11346406 DOI: 10.14336/ad.2023.1118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Accepted: 11/18/2023] [Indexed: 12/01/2023] Open
Abstract
FUS and TDP-43, two RNA-binding proteins from the heterogeneous nuclear ribonucleoprotein family, have gained significant attention in the field of neurodegenerative diseases due to their association with amyotrophic lateral sclerosis (ALS) and frontotemporal degeneration (FTD). They possess folded domains for binding ATP and various nucleic acids including DNA and RNA, as well as substantial intrinsically disordered regions (IDRs) including prion-like domains (PLDs) and RG-/RGG-rich regions. They play vital roles in various cellular processes, including transcription, splicing, microRNA maturation, RNA stability and transport and DNA repair. In particular, they are key components for forming ribonucleoprotein granules and stress granules (SGs) through homotypic or heterotypic liquid-liquid phase separation (LLPS). Strikingly, liquid-like droplets formed by FUS and TDP-43 may undergo aging to transform into less dynamic assemblies such as hydrogels, inclusions, and amyloid fibrils, which are the pathological hallmarks of ALS and FTD. This review aims to synthesize and consolidate the biophysical knowledge of the sequences, structures, stability, dynamics, and inter-domain interactions of FUS and TDP-43 domains, so as to shed light on the molecular mechanisms underlying their liquid-liquid phase separation (LLPS) and amyloidosis. The review further delves into the mechanisms through which ALS-causing mutants of the well-folded hPFN1 disrupt the dynamics of LLPS of FUS prion-like domain, providing key insights into a potential mechanism for misfolding/aggregation-prone proteins to cause neurodegenerative diseases and aging by gain of functions. With better understanding of different biophysical aspects of FUS and TDP-43, the ultimate goal is to develop drugs targeting LLPS and amyloidosis, which could mediate protein homeostasis within cells and lead to new treatments for currently intractable diseases, particularly neurodegenerative diseases such as ALS, FTD and aging. However, the study of membrane-less organelles and condensates is still in its infancy and therefore the review also highlights key questions that require future investigation.
Collapse
|
2
|
Huang WP, Ellis BCS, Hodgson RE, Sanchez Avila A, Kumar V, Rayment J, Moll T, Shelkovnikova TA. Stress-induced TDP-43 nuclear condensation causes splicing loss of function and STMN2 depletion. Cell Rep 2024; 43:114421. [PMID: 38941189 DOI: 10.1016/j.celrep.2024.114421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Revised: 04/04/2024] [Accepted: 06/14/2024] [Indexed: 06/30/2024] Open
Abstract
TDP-43 protein is dysregulated in several neurodegenerative diseases, which often have a multifactorial nature and may have extrinsic stressors as a "second hit." TDP-43 undergoes reversible nuclear condensation in stressed cells including neurons. Here, we demonstrate that stress-inducible nuclear TDP-43 condensates are RNA-depleted, non-liquid assemblies distinct from the known nuclear bodies. Their formation requires TDP-43 oligomerization and ATP and is inhibited by RNA. Using a confocal nanoscanning assay, we find that amyotrophic lateral sclerosis (ALS)-linked mutations alter stress-induced TDP-43 condensation by changing its affinity to liquid-like ribonucleoprotein assemblies. Stress-induced nuclear condensation transiently inactivates TDP-43, leading to loss of interaction with its protein binding partners and loss of function in splicing. Splicing changes are especially prominent and persisting for STMN2 RNA, and STMN2 protein becomes rapidly depleted early during stress. Our results point to early pathological changes to TDP-43 in the nucleus and support therapeutic modulation of stress response in ALS.
Collapse
Affiliation(s)
- Wan-Ping Huang
- Sheffield Institute for Translational Neuroscience and Neuroscience Institute, University of Sheffield, Sheffield, UK
| | - Brittany C S Ellis
- Sheffield Institute for Translational Neuroscience and Neuroscience Institute, University of Sheffield, Sheffield, UK
| | - Rachel E Hodgson
- Sheffield Institute for Translational Neuroscience and Neuroscience Institute, University of Sheffield, Sheffield, UK
| | - Anna Sanchez Avila
- Sheffield Institute for Translational Neuroscience and Neuroscience Institute, University of Sheffield, Sheffield, UK
| | - Vedanth Kumar
- Sheffield Institute for Translational Neuroscience and Neuroscience Institute, University of Sheffield, Sheffield, UK
| | - Jessica Rayment
- Sheffield Institute for Translational Neuroscience and Neuroscience Institute, University of Sheffield, Sheffield, UK
| | - Tobias Moll
- Sheffield Institute for Translational Neuroscience and Neuroscience Institute, University of Sheffield, Sheffield, UK
| | - Tatyana A Shelkovnikova
- Sheffield Institute for Translational Neuroscience and Neuroscience Institute, University of Sheffield, Sheffield, UK.
| |
Collapse
|
3
|
Ding M, Xu W, Pei G, Li P. Long way up: rethink diseases in light of phase separation and phase transition. Protein Cell 2024; 15:475-492. [PMID: 38069453 PMCID: PMC11214837 DOI: 10.1093/procel/pwad057] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Accepted: 11/24/2023] [Indexed: 07/02/2024] Open
Abstract
Biomolecular condensation, driven by multivalency, serves as a fundamental mechanism within cells, facilitating the formation of distinct compartments, including membraneless organelles that play essential roles in various cellular processes. Perturbations in the delicate equilibrium of condensation, whether resulting in gain or loss of phase separation, have robustly been associated with cellular dysfunction and physiological disorders. As ongoing research endeavors wholeheartedly embrace this newly acknowledged principle, a transformative shift is occurring in our comprehension of disease. Consequently, significant strides have been made in unraveling the profound relevance and potential causal connections between abnormal phase separation and various diseases. This comprehensive review presents compelling recent evidence that highlight the intricate associations between aberrant phase separation and neurodegenerative diseases, cancers, and infectious diseases. Additionally, we provide a succinct summary of current efforts and propose innovative solutions for the development of potential therapeutics to combat the pathological consequences attributed to aberrant phase separation.
Collapse
Affiliation(s)
- Mingrui Ding
- State Key Laboratory of Membrane Biology & Frontier Research Center for Biological Structure, School of Life Sciences, Tsinghua University, Beijing 100084, China
- Tsinghua-Peking Center for Life Sciences, Beijing 100084, China
- NuPhase Therapeutics, Beijing 100083, China
| | - Weifan Xu
- State Key Laboratory of Membrane Biology & Frontier Research Center for Biological Structure, School of Life Sciences, Tsinghua University, Beijing 100084, China
- Tsinghua-Peking Center for Life Sciences, Beijing 100084, China
- NuPhase Therapeutics, Beijing 100083, China
| | - Gaofeng Pei
- State Key Laboratory of Membrane Biology & Frontier Research Center for Biological Structure, School of Life Sciences, Tsinghua University, Beijing 100084, China
- Tsinghua-Peking Center for Life Sciences, Beijing 100084, China
| | - Pilong Li
- State Key Laboratory of Membrane Biology & Frontier Research Center for Biological Structure, School of Life Sciences, Tsinghua University, Beijing 100084, China
- Tsinghua-Peking Center for Life Sciences, Beijing 100084, China
| |
Collapse
|
4
|
Mukherjee S, Poudyal M, Dave K, Kadu P, Maji SK. Protein misfolding and amyloid nucleation through liquid-liquid phase separation. Chem Soc Rev 2024; 53:4976-5013. [PMID: 38597222 DOI: 10.1039/d3cs01065a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/11/2024]
Abstract
Liquid-liquid phase separation (LLPS) is an emerging phenomenon in cell physiology and diseases. The weak multivalent interaction prerequisite for LLPS is believed to be facilitated through intrinsically disordered regions, which are prevalent in neurodegenerative disease-associated proteins. These aggregation-prone proteins also exhibit an inherent property for phase separation, resulting in protein-rich liquid-like droplets. The very high local protein concentration in the water-deficient confined microenvironment not only drives the viscoelastic transition from the liquid to solid-like state but also most often nucleate amyloid fibril formation. Indeed, protein misfolding, oligomerization, and amyloid aggregation are observed to be initiated from the LLPS of various neurodegeneration-related proteins. Moreover, in these cases, neurodegeneration-promoting genetic and environmental factors play a direct role in amyloid aggregation preceded by the phase separation. These cumulative recent observations ignite the possibility of LLPS being a prominent nucleation mechanism associated with aberrant protein aggregation. The present review elaborates on the nucleation mechanism of the amyloid aggregation pathway and the possible early molecular events associated with amyloid-related protein phase separation. It also summarizes the recent advancement in understanding the aberrant phase transition of major proteins contributing to neurodegeneration focusing on the common disease-associated factors. Overall, this review proposes a generic LLPS-mediated multistep nucleation mechanism for amyloid aggregation and its implication in neurodegeneration.
Collapse
Affiliation(s)
- Semanti Mukherjee
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India.
| | - Manisha Poudyal
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India.
| | - Kritika Dave
- Sunita Sanghi Centre of Aging and Neurodegenerative Diseases, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Pradeep Kadu
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India.
| | - Samir K Maji
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India.
- Sunita Sanghi Centre of Aging and Neurodegenerative Diseases, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| |
Collapse
|
5
|
Song J. Adenosine Triphosphate: The Primordial Molecule That Controls Protein Homeostasis and Shapes the Genome-Proteome Interface. Biomolecules 2024; 14:500. [PMID: 38672516 PMCID: PMC11048592 DOI: 10.3390/biom14040500] [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: 03/29/2024] [Revised: 04/15/2024] [Accepted: 04/17/2024] [Indexed: 04/28/2024] Open
Abstract
Adenosine triphosphate (ATP) acts as the universal energy currency that drives various biological processes, while nucleic acids function to store and transmit genetic information for all living organisms. Liquid-liquid phase separation (LLPS) represents the common principle for the formation of membrane-less organelles (MLOs) composed of proteins rich in intrinsically disordered regions (IDRs) and nucleic acids. Currently, while IDRs are well recognized to facilitate LLPS through dynamic and multivalent interactions, the precise mechanisms by which ATP and nucleic acids affect LLPS still remain elusive. This review summarizes recent NMR results on the LLPS of human FUS, TDP-43, and the viral nucleocapsid (N) protein of SARS-CoV-2, as modulated by ATP and nucleic acids, revealing the following: (1) ATP binds to folded domains overlapping with nucleic-acid-binding interfaces; (2) ATP and nucleic acids interplay to biphasically modulate LLPS by competitively binding to overlapping pockets of folded domains and Arg/Lys within IDRs; (3) ATP energy-independently induces protein folding with the highest efficiency known so far. As ATP likely emerged in the prebiotic monomeric world, while LLPS represents a pivotal mechanism to concentrate and compartmentalize rare molecules for forming primordial cells, ATP appears to control protein homeostasis and shape genome-proteome interfaces throughout the evolutionary trajectory, from prebiotic origins to modern cells.
Collapse
Affiliation(s)
- Jianxing Song
- Department of Biological Sciences, Faculty of Science, National University of Singapore, 10 Kent Ridge Crescent, Singapore 119260, Singapore
| |
Collapse
|
6
|
Helmold BR, Pauss KE, Ozdinler PH. TDP-43 protein interactome informs about perturbed canonical pathways and may help develop personalized medicine approaches for patients with TDP-43 pathology. Drug Discov Today 2023; 28:103769. [PMID: 37714405 PMCID: PMC10872580 DOI: 10.1016/j.drudis.2023.103769] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Revised: 08/22/2023] [Accepted: 09/08/2023] [Indexed: 09/17/2023]
Abstract
Transactive response DNA binding protein of 43 kDa (TDP-43) pathology is a common proteinopathy observed among a broad spectrum of patients with neurodegenerative disease, regardless of the mutation. This suggests that protein-protein interactions of TDP-43 with other proteins may in part be responsible for the pathology. To gain better insights, we investigated TDP-43-binding proteins in each domain and correlated these interactions with canonical pathways. These investigations revealed key cellular events that are involved and are important at each domain and suggested previously identified compounds to modulate key aspects of these canonical pathways. Our approach proposes that personalized medicine approaches, which focus on perturbed cellular mechanisms would be feasible in the near future.
Collapse
Affiliation(s)
- Benjamin R Helmold
- Department of Neurology, Feinberg School of Medicine, Northwestern University, 303 E. Chicago Ave, Chicago, IL, 60611, USA
| | - Kate E Pauss
- Department of Neurology, Feinberg School of Medicine, Northwestern University, 303 E. Chicago Ave, Chicago, IL, 60611, USA
| | - P Hande Ozdinler
- Department of Neurology, Feinberg School of Medicine, Northwestern University, 303 E. Chicago Ave, Chicago, IL, 60611, USA; Center for Molecular Innovation and Drug Discovery, Center for Developmental Therapeutics, Chemistry of Life Processes Institute, Northwestern University, Evanston, IL 60611, USA; Mesulam Center for Cognitive Neurology and Alzheimer's Disease, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA; Feinberg School of Medicine, Les Turner ALS Center at Northwestern University, Chicago, IL 60611, USA.
| |
Collapse
|
7
|
Lim SM, Nahm M, Kim SH. Proteostasis and Ribostasis Impairment as Common Cell Death Mechanisms in Neurodegenerative Diseases. J Clin Neurol 2023; 19:101-114. [PMID: 36854331 PMCID: PMC9982182 DOI: 10.3988/jcn.2022.0379] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2022] [Revised: 12/07/2022] [Accepted: 12/07/2022] [Indexed: 03/02/2023] Open
Abstract
The cellular homeostasis of proteins (proteostasis) and RNA metabolism (ribostasis) are essential for maintaining both the structure and function of the brain. However, aging, cellular stress conditions, and genetic contributions cause disturbances in proteostasis and ribostasis that lead to protein misfolding, insoluble aggregate deposition, and abnormal ribonucleoprotein granule dynamics. In addition to neurons being primarily postmitotic, nondividing cells, they are more susceptible to the persistent accumulation of abnormal aggregates. Indeed, defects associated with the failure to maintain proteostasis and ribostasis are common pathogenic components of age-related neurodegenerative diseases, including Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis. Furthermore, the neuronal deposition of misfolded and aggregated proteins can cause both increased toxicity and impaired physiological function, which lead to neuronal dysfunction and cell death. There is recent evidence that irreversible liquid-liquid phase separation (LLPS) is responsible for the pathogenic aggregate formation of disease-related proteins, including tau, α-synuclein, and RNA-binding proteins, including transactive response DNA-binding protein 43, fused in sarcoma, and heterogeneous nuclear ribonucleoprotein A1. Investigations of LLPS and its control therefore suggest that chaperone/disaggregase, which reverse protein aggregation, are valuable therapeutic targets for effective treatments for neurological diseases. Here we review and discuss recent studies to highlight the importance of understanding the common cell death mechanisms of proteostasis and ribostasis in neurodegenerative diseases.
Collapse
Affiliation(s)
- Su Min Lim
- Cell Therapy Center and Department of Neurology, College of Medicine, Hanyang University, Seoul, Korea
| | - Minyeop Nahm
- Dementia Research Group, Korea Brain Research Institute, Daegu, Korea
| | - Seung Hyun Kim
- Cell Therapy Center and Department of Neurology, College of Medicine, Hanyang University, Seoul, Korea.
| |
Collapse
|
8
|
Zalar M, Bye J, Curtis R. Nonspecific Binding of Adenosine Tripolyphosphate and Tripolyphosphate Modulates the Phase Behavior of Lysozyme. J Am Chem Soc 2023; 145:929-943. [PMID: 36608272 PMCID: PMC9853864 DOI: 10.1021/jacs.2c09615] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Adenosine tripolyphosphate (ATP) is a small polyvalent anion that has recently been shown to interact with proteins and have a major impact on assembly processes involved in biomolecular condensate formation and protein aggregation. However, the nature of non-specific protein-ATP interactions and their effects on protein solubility are largely unknown. Here, the binding of ATP to the globular model protein is characterized in detail using X-ray crystallography and nuclear magnetic resonance (NMR). Using NMR, we identified six ATP binding sites on the lysozyme surface, with one known high-affinity nucleic acid binding site and five non-specific previously unknown sites with millimolar affinities that also bind tripolyphosphate (TPP). ATP binding occurs primarily through the polyphosphate moiety, which was confirmed by the X-ray structure of the lysozyme-ATP complex. Importantly, ATP binds preferentially to arginine over lysine in non-specific binding sites. ATP and TPP have similar effects on solution-phase protein-protein interactions. At low salt concentrations, ion binding to lysozyme causes precipitation, while at higher salt concentrations, redissolution occurs. The addition of an equimolar concentration of magnesium to ATP does not alter ATP binding affinities but prevents lysozyme precipitation. These findings have important implications for both protein crystallization and cell biology. Crystallization occurs readily in ATP solutions outside the well-established crystallization window. In the context of cell biology, the findings suggest that ATP binds non-specifically to folded proteins in physiological conditions. Based on the nature of the binding sites identified by NMR, we propose several mechanisms for how ATP binding can prevent the aggregation of natively folded proteins.
Collapse
|
9
|
Hu G, Ou X, Li J. Mechanistic Insight on General Protein-Binding Ability of ATP and the Impacts of Arginine Residues. J Phys Chem B 2022; 126:4647-4658. [PMID: 35713479 DOI: 10.1021/acs.jpcb.2c01478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Recent experiments suggested that adenosine triphosphate (ATP) can regulate liquid-liquid phase separation (LLPS) of various proteins and inhibit protein aggregations at its physiological concentration, which is highly correlated with the nonspecific interactions of ATP to a wide variety of proteins. However, the mechanism underlying the general binding capability of ATP largely remains unclear. In this work, we used molecular dynamics simulation to study the binding of ATPs to three proteins with distinct net charges: TDP-43 NTD (-7 e), TAF15-RRM (0 e), HWEL (+8 e). Negatively charged ATP exhibits a strong trend to accumulate around all of these proteins. While only a fraction of the accumulated ATPs directly binds to the limited regions of the protein surface, additional ATPs indirectly bind to proteins by aggregating into ATP clusters. Hence, the proportion of the directly bound ATPs in the clusters as well as their binding regions can be adjusted in response to different proteins, which makes ATP well adapted to a variety of proteins. Moreover, our results suggest that ATP tightly binds to Arg with high affinity, and Arg dominates the direct binding of ATP. Meanwhile, Arg also affects the self-association of accumulated ATPs. The size of the ATP cluster is effectively regulated by the distribution of Arg. Considering the ubiquity of Arg in proteins, our findings are helpful to understand the general binding capability of ATP.
Collapse
Affiliation(s)
- Guorong Hu
- Zhejiang Province Key Laboratory of Quantum Technology and Device, School of Physics, Zhejiang University, Zheda Road 38, Hangzhou 310027, China
| | - Xinwen Ou
- Zhejiang Province Key Laboratory of Quantum Technology and Device, School of Physics, Zhejiang University, Zheda Road 38, Hangzhou 310027, China
| | - Jingyuan Li
- Zhejiang Province Key Laboratory of Quantum Technology and Device, School of Physics, Zhejiang University, Zheda Road 38, Hangzhou 310027, China
| |
Collapse
|
10
|
Liao YZ, Ma J, Dou JZ. The Role of TDP-43 in Neurodegenerative Disease. Mol Neurobiol 2022; 59:4223-4241. [DOI: 10.1007/s12035-022-02847-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 04/23/2022] [Indexed: 12/14/2022]
|
11
|
TDP-43 pathology: from noxious assembly to therapeutic removal. Prog Neurobiol 2022; 211:102229. [DOI: 10.1016/j.pneurobio.2022.102229] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Revised: 12/08/2021] [Accepted: 01/26/2022] [Indexed: 02/08/2023]
|
12
|
ATP and Tri-Polyphosphate (TPP) Suppress Protein Aggregate Growth by a Supercharging Mechanism. Biomedicines 2021; 9:biomedicines9111646. [PMID: 34829875 PMCID: PMC8616003 DOI: 10.3390/biomedicines9111646] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 10/27/2021] [Accepted: 11/03/2021] [Indexed: 11/17/2022] Open
Abstract
A common strategy to increase aggregation resistance is through rational mutagenesis to supercharge proteins, which leads to high colloidal stability, but often has the undesirable effect of lowering conformational stability. We show this trade-off can be overcome by using small multivalent polyphosphate ions, adenosine triphosphate (ATP) and tripolyphosphate (TPP) as excipients. These ions are equally effective at suppressing aggregation of ovalbumin and bovine serum albumin (BSA) upon thermal stress as monitored by dynamic and static light scattering. Monomer loss kinetic studies, combined with measurements of native state protein–protein interactions and ζ-potentials, indicate the ions reduce aggregate growth by increasing the protein colloidal stability through binding and overcharging the protein. Out of three additional proteins studied, ribonuclease A (RNaseA), α-chymotrypsinogen (α-Cgn), and lysozyme, we only observed a reduction in aggregate growth for RNaseA, although overcharging by the poly-phosphate ions still occurs for lysozyme and α-Cgn. Because the salts do not alter protein conformational stability, using them as excipients could be a promising strategy for stabilizing biopharmaceuticals once the protein structural factors that determine whether multivalent ion binding will increase colloidal stability are better elucidated. Our findings also have biological implications. Recently, it has been proposed that ATP also plays an important role in maintaining intracellular biological condensates and preventing protein aggregation in densely packed cellular environments. We expect electrostatic interactions are a significant factor in determining the stabilizing ability of ATP towards maintaining proteins in non-dispersed states in vivo.
Collapse
|
13
|
Strategies in the design and development of (TAR) DNA-binding protein 43 (TDP-43) binding ligands. Eur J Med Chem 2021; 225:113753. [PMID: 34388383 DOI: 10.1016/j.ejmech.2021.113753] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 07/16/2021] [Accepted: 08/05/2021] [Indexed: 01/09/2023]
Abstract
The human transactive responsive (TAR) DNA-binding protein 43 (TDP-43) is involved in a number of physiological processes in the body. Its primary function involves RNA regulation. The TDP-43 protein is also involved in many diseases such as amyotrophic lateral sclerosis (ALS), frontotemporal dementia (FTD), Alzheimer's disease (AD), Parkinson's disease (PD) and even cancers. These TDP-43 mediated diseases are collectively called as TDP-43 proteinopathies. Intense research in the last decade has increased our understanding on TDP-43 structure and function in biology. The three-dimensional structures of TDP-43 domains such as N-terminal domain (NTD), RNA-recognition motif-1 (RRM1), RNA-recognition motif-2 (RRM2) and the C-terminal domain (CTD) or low-complexity domain (LCD) have been solved. These structures have yielded insights into novel binding sites and pockets at various TDP-43 domains, which can be targeted by designing a diverse library of ligands including small molecules, peptides and oligonucleotides as molecular tools to (i) study TDP-43 function, (ii) develop novel diagnostic agents and (iii) discover disease-modifying therapies to treat TDP-43 proteinopathies. This review provides a summary on recent progress in the development of TDP-43 binding ligands and uses the solved structures of various TDP-43 domains to investigate putative ligand binding regions that can be exploited to discover novel molecular probes to modulate TDP-43 structure and function.
Collapse
|
14
|
Song J. Adenosine triphosphate energy-independently controls protein homeostasis with unique structure and diverse mechanisms. Protein Sci 2021; 30:1277-1293. [PMID: 33829608 PMCID: PMC8197423 DOI: 10.1002/pro.4079] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 03/30/2021] [Accepted: 04/02/2021] [Indexed: 02/06/2023]
Abstract
Proteins function in the crowded cellular environments with high salt concentrations, thus facing tremendous challenges of misfolding/aggregation which represents a pathological hallmark of aging and an increasing spectrum of human diseases. Recently, intrinsically disordered regions (IDRs) were recognized to drive liquid-liquid phase separation (LLPS), a common principle for organizing cellular membraneless organelles (MLOs). ATP, the universal energy currency for all living cells, mysteriously has concentrations of 2-12 mM, much higher than required for its previously-known functions. Only recently, ATP was decoded to behave as a biological hydrotrope to inhibit protein LLPS and aggregation at mM. We further revealed that ATP also acts as a bivalent binder, which not only biphasically modulates LLPS driven by IDRs of human and viral proteins, but also bind to the conserved nucleic-acid-binding surfaces of the folded proteins. Most unexpectedly, ATP appears to act as a hydration mediator to antagonize the crowding-induced destabilization as well as to enhance folding of proteins without significant binding. Here, this review focuses on summarizing the results of these biophysical studies and discussing their implications in an evolutionary context. By linking triphosphate with unique hydration property to adenosine, ATP appears to couple the ability for establishing hydrophobic, π-π, π-cation and electrostatic interactions to the capacity in mediating hydration of proteins, which is at the heart of folding, dynamics, stability, phase separation and aggregation. Consequently, ATP acquired a category of functions at ~mM to energy-independently control protein homeostasis with diverse mechanisms, thus implying a link between cellular ATP concentrations and protein-aggregation diseases.
Collapse
Affiliation(s)
- Jianxing Song
- Department of Biological Sciences, Faculty of ScienceNational University of SingaporeSingaporeSingapore
| |
Collapse
|
15
|
Chen S, Zhou RL, Zhang W, Che CH, Feng SY, Huang HP, Liu CY, Zou ZY. Novel TARDBP missense mutation caused familial amyotrophic lateral sclerosis with frontotemporal dementia and parkinsonism. Neurobiol Aging 2021; 107:168-173. [PMID: 34175147 DOI: 10.1016/j.neurobiolaging.2021.05.017] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 05/24/2021] [Accepted: 05/24/2021] [Indexed: 10/21/2022]
Abstract
Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disorder that predominately involves the motor neurons in the brain and spinal cord. The TARDBP gene, encoding TAR DNA-binding protein 43 (TDP-43) protein, has been identified as a major causative gene in ALS. In this study, we screened 275 SALS patients and 20 unrelated FALS probands for TARDBP mutations. We identified three TARDBP mutations in three SALS patients and two TARDBP mutations in two FALS probands, including a previously unreported mutation, p.K176I, in FALS patients consistent with frontotemporal dementia (FTD) and parkinsonism. The p.K176I mutation is the first mutation outside exon 6 of the TARDBP gene manifesting parkinsonism and the first TARDBP mutation manifesting parkinsonism identified in the Chinese population. Our results support that TARDBP mutations are one of the most common changes in both FALS and SALS in China. Patients with TARDBP mutations may have a broad phenotype spectrum of ALS, FTD, and parkinsonism. The TARDBP gene should be included in genetic screening for ALS with FTD, and/or parkinsonism.
Collapse
Affiliation(s)
- Sheng Chen
- Department of Neurology, Fujian Medical University Union Hospital, Fuzhou, China; Institute of Clinical Neurology, Fujian Medical University, Fuzhou, China
| | - Rui-Ling Zhou
- Department of Neurology, Fujian Provincial Hospital, Fuzhou, China
| | - Wei Zhang
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX; AmCare Genomics Lab, Guangzhou, China
| | - Chun-Hui Che
- Department of Neurology, Fujian Medical University Union Hospital, Fuzhou, China
| | - Shu-Yan Feng
- Department of Neurology, Henan Provincial People's Hospital, Zhengzhou, China
| | - Hua-Pin Huang
- Department of Neurology, Fujian Medical University Union Hospital, Fuzhou, China; Institute of Clinical Neurology, Fujian Medical University, Fuzhou, China
| | - Chang-Yun Liu
- Department of Neurology, Fujian Medical University Union Hospital, Fuzhou, China; Institute of Clinical Neurology, Fujian Medical University, Fuzhou, China.
| | - Zhang-Yu Zou
- Department of Neurology, Fujian Medical University Union Hospital, Fuzhou, China; Institute of Clinical Neurology, Fujian Medical University, Fuzhou, China.
| |
Collapse
|
16
|
Zbinden A, Pérez-Berlanga M, De Rossi P, Polymenidou M. Phase Separation and Neurodegenerative Diseases: A Disturbance in the Force. Dev Cell 2021; 55:45-68. [PMID: 33049211 DOI: 10.1016/j.devcel.2020.09.014] [Citation(s) in RCA: 233] [Impact Index Per Article: 77.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2020] [Revised: 09/09/2020] [Accepted: 09/13/2020] [Indexed: 12/12/2022]
Abstract
Protein aggregation is the main hallmark of neurodegenerative diseases. Many proteins found in pathological inclusions are known to undergo liquid-liquid phase separation, a reversible process of molecular self-assembly. Emerging evidence supports the hypothesis that aberrant phase separation behavior may serve as a trigger of protein aggregation in neurodegeneration, and efforts to understand and control the underlying mechanisms are underway. Here, we review similarities and differences among four main proteins, α-synuclein, FUS, tau, and TDP-43, which are found aggregated in different diseases and were independently shown to phase separate. We discuss future directions in the field that will help shed light on the molecular mechanisms of aggregation and neurodegeneration.
Collapse
Affiliation(s)
- Aurélie Zbinden
- Department of Quantitative Biomedicine, University of Zürich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Manuela Pérez-Berlanga
- Department of Quantitative Biomedicine, University of Zürich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Pierre De Rossi
- Department of Quantitative Biomedicine, University of Zürich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Magdalini Polymenidou
- Department of Quantitative Biomedicine, University of Zürich, Winterthurerstrasse 190, 8057 Zurich, Switzerland.
| |
Collapse
|
17
|
Song B, Yu J, Sun Y, Wang Q, Xu S, Jia Y, Lin S, Zhang Y, Wang C, Zhang Y, Zhang X. Microfluidics for the rapid detection of Escherichia coli O157:H7 using antibody-coated microspheres. Bioengineered 2021; 12:392-401. [PMID: 33472509 PMCID: PMC8806228 DOI: 10.1080/21655979.2020.1870805] [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] [Indexed: 12/26/2022] Open
Abstract
This study developed a novel method for the rapid detection of Escherichia coli (E. coli) O157:H7 on a microfluidic platform. First, the concentration of bacteria in a sample was determined with the adenosine triphosphate (ATP) method. Then, the specific detection of E. coli was achieved in a microfluidic chip by the immune-microsphere technique. The influences of the culture time, flow rate and capture time on the detection of the target bacteria were investigated systematically. Generally, with increasing capture time, more bacteria could be captured by the microspheres, which had a positive effect on bacterial detection. Furthermore, the sensitivity and specificity of the method were also tested. The results showed that this method could specifically detect E. coli with a sensitivity as high as 49.1 cfu/μL; the consumption of bacteria was 1 μL, and the reagent was at the microliter level. The testing time can be controlled within one and a half hours, and the cost of testing was approximately RMB 10. The method described in this article is simple and accurate and has great application value in bacterial detection for medical diagnostics.
Collapse
Affiliation(s)
- Bo Song
- Department of Clinical Pathogen, Medical Technology College, Qiqihar Medical University , Qiqihar, China
| | - Jiayuan Yu
- Clinical Laboratory, Microbial Virus Group, the Second Affiliated Hospital of Heilongjiang University of Traditional Chinese Medicine , Harbin, China
| | - Yan Sun
- Department of Clinical Pathogen, Medical Technology College, Qiqihar Medical University , Qiqihar, China
| | - Qiao Wang
- Department of Stomatology, The Second Affiliated Hospital of Qiqihar Medical University , Qiqihar, China
| | - Shengnan Xu
- Medical Technology College, Qiqihar Medical University , Qiqihar, China
| | - Yichen Jia
- Medical Technology College, Qiqihar Medical University , Qiqihar, China
| | - Shuying Lin
- Medical Technology College, Qiqihar Medical University , Qiqihar, China
| | - Yueying Zhang
- Medical Technology College, Qiqihar Medical University , Qiqihar, China
| | - Chen Wang
- Medical Technology College, Qiqihar Medical University , Qiqihar, China
| | - Yingbo Zhang
- Pathology College, Qiqihar Medical University , Qiqihar, China
| | | |
Collapse
|
18
|
Tethering-induced destabilization and ATP-binding for tandem RRM domains of ALS-causing TDP-43 and hnRNPA1. Sci Rep 2021; 11:1034. [PMID: 33441818 PMCID: PMC7806782 DOI: 10.1038/s41598-020-80524-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2020] [Accepted: 12/21/2020] [Indexed: 12/12/2022] Open
Abstract
TDP-43 and hnRNPA1 contain tandemly-tethered RNA-recognition-motif (RRM) domains, which not only functionally bind an array of nucleic acids, but also participate in aggregation/fibrillation, a pathological hallmark of various human diseases including amyotrophic lateral sclerosis (ALS), frontotemporal dementia (FTD), alzheimer's disease (AD) and Multisystem proteinopathy (MSP). Here, by DSF, NMR and MD simulations we systematically characterized stability, ATP-binding and conformational dynamics of TDP-43 and hnRNPA1 RRM domains in both tethered and isolated forms. The results reveal three key findings: (1) upon tethering TDP-43 RRM domains become dramatically coupled and destabilized with Tm reduced to only 49 °C. (2) ATP specifically binds TDP-43 and hnRNPA1 RRM domains, in which ATP occupies the similar pockets within the conserved nucleic-acid-binding surfaces, with the affinity slightly higher to the tethered than isolated forms. (3) MD simulations indicate that the tethered RRM domains of TDP-43 and hnRNPA1 have higher conformational dynamics than the isolated forms. Two RRM domains become coupled as shown by NMR characterization and analysis of inter-domain correlation motions. The study explains the long-standing puzzle that the tethered TDP-43 RRM1–RRM2 is particularly prone to aggregation/fibrillation, and underscores the general role of ATP in inhibiting aggregation/fibrillation of RRM-containing proteins. The results also rationalize the observation that the risk of aggregation-causing diseases increases with aging.
Collapse
|