1
|
Hurtle B, Donnelly CJ, Zhang X, Thathiah A. Live-cell visualization of tau aggregation in human neurons. Commun Biol 2024; 7:1143. [PMID: 39277689 PMCID: PMC11401922 DOI: 10.1038/s42003-024-06840-z] [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: 08/01/2023] [Accepted: 09/04/2024] [Indexed: 09/17/2024] Open
Abstract
Alzheimer's disease (AD) and more than twenty other dementias, termed tauopathies, are pathologically defined by insoluble aggregates of the microtubule-associated protein tau (MAPT). Although tau aggregation correlates with AD symptomology, the specific tau species, i.e., monomers, soluble oligomers, and insoluble aggregates that induce neurotoxicity are incompletely understood. We developed a light-responsive tau protein (optoTAU) and used viscosity-sensitive AggFluor probes to investigate the consequence(s) of tau aggregation in human neurons and identify modifiers of tau aggregation in AD and other tauopathies. We determined that optoTAU reproduces biological and structural properties of tau aggregation observed in human brains and the pathophysiological transition in tau solubility in live cells. We also provide proof-of-concept for the utilization of optoTAU as a pharmacological platform to identify modifiers of tau aggregation. These findings have broad implications for the characterization of aggregation-prone proteins and investigation of the complex relationship between protein solubility, cellular function, and disease progression.
Collapse
Affiliation(s)
- Bryan Hurtle
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
- Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, USA
| | - Christopher J Donnelly
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
- University of Pittsburgh Brain Institute, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
- Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
- LiveLikeLou Center for ALS Research, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
- Center for Protein Conformational Diseases, Kenneth P. Dietrich School of Arts and Sciences, University of Pittsburgh, Pittsburgh, PA, USA
| | - Xin Zhang
- Department of Chemistry, School of Science and Research Center for Industries of the Future, Westlake University, Hangzhou, Zhejiang, P. R. China
| | - Amantha Thathiah
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
- University of Pittsburgh Brain Institute, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
- Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
- Center for Protein Conformational Diseases, Kenneth P. Dietrich School of Arts and Sciences, University of Pittsburgh, Pittsburgh, PA, USA.
| |
Collapse
|
2
|
Dilissen S, Silva PL, Smolentseva A, Kache T, Thoelen R, Hendrix J. Characterisation of biocondensate microfluidic flow using array-detector FCS. Biochim Biophys Acta Gen Subj 2024; 1868:130673. [PMID: 39029539 DOI: 10.1016/j.bbagen.2024.130673] [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: 03/30/2024] [Revised: 07/05/2024] [Accepted: 07/15/2024] [Indexed: 07/21/2024]
Abstract
BACKGROUND Biomolecular condensation via liquid-liquid phase separation (LLPS) is crucial for orchestrating cellular activities temporospatially. Although the rheological heterogeneity of biocondensates and the structural dynamics of their constituents carry critical functional information, methods to quantitatively study biocondensates are lacking. Single-molecule fluorescence research can offer insights into biocondensation mechanisms. Unfortunately, as dense condensates tend to sink inside their dilute aqueous surroundings, studying their properties via methods relying on Brownian diffusion may fail. METHODS We take a first step towards single-molecule research on condensates of Tau protein under flow in a microfluidic channel of an in-house developed microfluidic chip. Fluorescence correlation spectroscopy (FCS), a well-known technique to collect molecular characteristics within a sample, was employed with a newly commercialised technology, where FCS is performed on an array detector (AD-FCS), providing detailed diffusion and flow information. RESULTS The AD-FCS technology allowed characterising our microfluidic chip, revealing 3D flow profiles. Subsequently, AD-FCS allowed mapping the flow of Tau condensates while measuring their burst durations through the stationary laser. Lastly, AD-FCS allowed obtaining flow velocity and burst duration data, the latter of which was used to estimate the condensate size distribution within LLPS samples. CONCLUSION Studying biocondensates under flow through AD-FCS is promising for single-molecule experiments. In addition, AD-FCS shows its ability to estimate the size distribution in condensate samples in a convenient manner, prompting a new way of investigating biocondensate phase diagrams. GENERAL SIGNIFICANCE We show that AD-FCS is a valuable tool for advancing research on understanding and characterising LLPS properties of biocondensates.
Collapse
Affiliation(s)
- Stijn Dilissen
- UHasselt, Dynamic Bioimaging Lab, Advanced Optical Microscopy Centre, Biomedical Research Institute, Agoralaan C (BIOMED), B3590 Diepenbeek, Belgium; UHasselt, Biomedical Device Engineering group, Institute for Materials Research (IMO-IMOMEC), Wetenschapspark 1, B3590 Diepenbeek, Belgium
| | - Pedro L Silva
- UHasselt, Dynamic Bioimaging Lab, Advanced Optical Microscopy Centre, Biomedical Research Institute, Agoralaan C (BIOMED), B3590 Diepenbeek, Belgium
| | - Anastasia Smolentseva
- UHasselt, Dynamic Bioimaging Lab, Advanced Optical Microscopy Centre, Biomedical Research Institute, Agoralaan C (BIOMED), B3590 Diepenbeek, Belgium
| | - Tom Kache
- UHasselt, Dynamic Bioimaging Lab, Advanced Optical Microscopy Centre, Biomedical Research Institute, Agoralaan C (BIOMED), B3590 Diepenbeek, Belgium
| | - Ronald Thoelen
- UHasselt, Biomedical Device Engineering group, Institute for Materials Research (IMO-IMOMEC), Wetenschapspark 1, B3590 Diepenbeek, Belgium; IMOMEC Division, IMEC vzw, Wetenschapspark 1, B3590 Diepenbeek, Belgium
| | - Jelle Hendrix
- UHasselt, Dynamic Bioimaging Lab, Advanced Optical Microscopy Centre, Biomedical Research Institute, Agoralaan C (BIOMED), B3590 Diepenbeek, Belgium.
| |
Collapse
|
3
|
Joshi A, Avni A, Walimbe A, Rai SK, Sarkar S, Mukhopadhyay S. Hydrogen-Bonded Network of Water in Phase-Separated Biomolecular Condensates. J Phys Chem Lett 2024; 15:7724-7734. [PMID: 39042834 DOI: 10.1021/acs.jpclett.4c01153] [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: 07/25/2024]
Abstract
Biomolecular condensates formed via phase separation of intrinsically disordered proteins/regions (IDPs/IDRs) and nucleic acids are associated with cell physiology and disease. Water makes up for ∼60-70% of the condensate volume and is thought to influence the complex interplay of chain-chain and chain-solvent interactions, modulating the mesoscale properties of condensates. The behavior of water in condensates and the key roles of protein hydration water in driving the phase separation remain elusive. Here, we employ single-droplet vibrational Raman spectroscopy to illuminate the structural redistribution within protein hydration water during the phase separation of neuronal IDPs. Our Raman measurements reveal the changes in the water hydrogen bonding network during homotypic and heterotypic phase separation governed by various molecular drivers. Such single-droplet water Raman measurements offer a potent generic tool to unmask the intriguing interplay of sequence-encoded chain-chain and chain-solvent interactions governing macromolecular phase separation into membraneless organelles, synthetic condensates, and protocells.
Collapse
|
4
|
Lester E, Parker R. Tau, RNA, and RNA-Binding Proteins: Complex Interactions in Health and Neurodegenerative Diseases. Neuroscientist 2024; 30:458-472. [PMID: 36892034 DOI: 10.1177/10738584231154551] [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] [Indexed: 03/10/2023]
Abstract
The tau protein is a key contributor to multiple neurodegenerative diseases. The pathology of tau is thought to be related to tau's propensity to form self-templating fibrillar structures that allow tau fibers to propagate in the brain by prion-like mechanisms. Unresolved issues with respect to tau pathology are how the normal function of tau and its misregulation contribute to disease, how cofactors and cellular organelles influence the initiation and propagation of tau fibers, and determining the mechanism of tau toxicity. Herein, we review the connection between tau and degenerative diseases, the basis for tau fibrilization, and how that process interacts with cellular molecules and organelles. One emerging theme is that tau interacts with RNA and RNA-binding proteins, normally and in pathologic aggregates, which may provide insight into alterations in RNA regulation observed in disease.
Collapse
Affiliation(s)
- Evan Lester
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO, USA
- Medical Scientist Training Program, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Roy Parker
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO, USA
- Howard Hughes Medical Institute, University of Colorado, Boulder, CO, USA
| |
Collapse
|
5
|
Islam M, Shen F, Regmi D, Petersen K, Karim MRU, Du D. Tau liquid-liquid phase separation: At the crossroads of tau physiology and tauopathy. J Cell Physiol 2024; 239:e30853. [PMID: 35980344 PMCID: PMC9938090 DOI: 10.1002/jcp.30853] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Revised: 07/12/2022] [Accepted: 07/22/2022] [Indexed: 12/14/2022]
Abstract
Abnormal deposition of tau in neurons is a hallmark of Alzheimer's disease and several other neurodegenerative disorders. In the past decades, extensive efforts have been made to explore the mechanistic pathways underlying the development of tauopathies. Recently, the discovery of tau droplet formation by liquid-liquid phase separation (LLPS) has received a great deal of attention. It has been reported that tau condensates have a biological role in promoting and stabilizing microtubule (MT) assembly. Furthermore, it has been hypothesized that the transition of phase-separated tau droplets to a gel-like state and then to fibrils is associated with the pathology of neurodegenerative diseases. In this review, we outline LLPS, the structural disorder that facilitates tau droplet formation, the effects of posttranslational modification of tau on condensate formation, the physiological function of tau droplets, the pathways from droplet to toxic fibrils, and the therapeutic strategies for tauopathies that might evolve from toxic droplets. We expect a deeper understanding of tau LLPS will provide additional insights into tau physiology and tauopathies.
Collapse
Affiliation(s)
- Majedul Islam
- Department of Chemistry and Biochemistry, Florida Atlantic University, Boca Raton, Florida 33431, United States
| | - Fengyun Shen
- Department of Chemistry and Biochemistry, Florida Atlantic University, Boca Raton, Florida 33431, United States
| | - Deepika Regmi
- Department of Chemistry and Biochemistry, Florida Atlantic University, Boca Raton, Florida 33431, United States
| | - Katherine Petersen
- Department of Chemistry and Biochemistry, Florida Atlantic University, Boca Raton, Florida 33431, United States
| | - Md Raza Ul Karim
- Department of Chemistry and Biochemistry, Florida Atlantic University, Boca Raton, Florida 33431, United States
| | - Deguo Du
- Department of Chemistry and Biochemistry, Florida Atlantic University, Boca Raton, Florida 33431, United States
| |
Collapse
|
6
|
Alfano C, Fichou Y, Huber K, Weiss M, Spruijt E, Ebbinghaus S, De Luca G, Morando MA, Vetri V, Temussi PA, Pastore A. Molecular Crowding: The History and Development of a Scientific Paradigm. Chem Rev 2024; 124:3186-3219. [PMID: 38466779 PMCID: PMC10979406 DOI: 10.1021/acs.chemrev.3c00615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 02/13/2024] [Accepted: 02/26/2024] [Indexed: 03/13/2024]
Abstract
It is now generally accepted that macromolecules do not act in isolation but "live" in a crowded environment, that is, an environment populated by numerous different molecules. The field of molecular crowding has its origins in the far 80s but became accepted only by the end of the 90s. In the present issue, we discuss various aspects that are influenced by crowding and need to consider its effects. This Review is meant as an introduction to the theme and an analysis of the evolution of the crowding concept through time from colloidal and polymer physics to a more biological perspective. We introduce themes that will be more thoroughly treated in other Reviews of the present issue. In our intentions, each Review may stand by itself, but the complete collection has the aspiration to provide different but complementary perspectives to propose a more holistic view of molecular crowding.
Collapse
Affiliation(s)
- Caterina Alfano
- Structural
Biology and Biophysics Unit, Fondazione
Ri.MED, 90100 Palermo, Italy
| | - Yann Fichou
- CNRS,
Bordeaux INP, CBMN UMR 5248, IECB, University
of Bordeaux, F-33600 Pessac, France
| | - Klaus Huber
- Department
of Chemistry, University of Paderborn, 33098 Paderborn, Germany
| | - Matthias Weiss
- Experimental
Physics I, Physics of Living Matter, University
of Bayreuth, 95440 Bayreuth, Germany
| | - Evan Spruijt
- Institute
for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
| | - Simon Ebbinghaus
- Lehrstuhl
für Biophysikalische Chemie and Research Center Chemical Sciences
and Sustainability, Research Alliance Ruhr, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | - Giuseppe De Luca
- Dipartimento
di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche, Università degli Studi di Palermo, Viale delle Scienze, 90128 Palermo, Italy
| | | | - Valeria Vetri
- Dipartimento
di Fisica e Chimica − Emilio Segrè, Università degli Studi di Palermo, Viale delle Scienze, 90128 Palermo, Italy
| | | | - Annalisa Pastore
- King’s
College London, Denmark
Hill Campus, SE5 9RT London, United Kingdom
| |
Collapse
|
7
|
Venkatramani A, Ashtam A, Panda D. EB1 Increases the Dynamics of Tau Droplets and Inhibits Tau Aggregation: Implications in Tauopathies. ACS Chem Neurosci 2024; 15:1219-1233. [PMID: 38445984 DOI: 10.1021/acschemneuro.3c00815] [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] [Indexed: 03/07/2024] Open
Abstract
EB1, a microtubule plus end-tracking protein (+TIP), regulates microtubule dynamics. Recent evidence indicates cross-talk between EB proteins and tau, a microtubule-associated neuronal protein that is important for the growth and stability of microtubules. We investigated the interaction between tau and EB1 and the effect of binding of EB1 on tau function and aggregation. EB1 colocalized with tau in SH-SY5Y cells and coimmunoprecipitated with tau. Further, purified EB1 impaired the ability of adult tau to induce tubulin polymerization in vitro. EB1 bound to tau with a dissociation constant of 2.5 ± 0.7 μM. EB1 reduced heparin-induced tau aggregation with a half-maximal inhibitory concentration of 4.3 ± 0.2 μM, and increased the dynamics of tau in phase-separated droplets. The fluorescence recovery rate in tau droplets increased from 0.02 ± 0.01 to 0.07 ± 0.03 s-1, while the half-time of recovery decreased from 44.5 ± 14 to 13.5 ± 6 s in the presence of 8 μM EB1, suggesting a delay in the transition of tau from the soluble to aggregated form in tau liquid-liquid phase separation. EB1 decreased the rate of aggregation and increased the critical concentration of tau aggregation. Dynamic light scattering, atomic force microscopy, dot blot assays, and SDS-PAGE analysis showed that EB1 inhibited the formation of oligomers and higher-order aggregates of tau. The data suggest a novel role for EB1 as a regulator of tau function and aggregation, and the findings indicated the role of the EB family proteins in neuronal function and neurodegeneration.
Collapse
Affiliation(s)
- Anuradha Venkatramani
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Mumbai 400076, India
| | - Anvesh Ashtam
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Mumbai 400076, India
| | - Dulal Panda
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Mumbai 400076, India
- National Institute of Pharmaceutical Education and Research (NIPER), Sector 67, S.A.S. Nagar, Punjab 160062, India
| |
Collapse
|
8
|
Abasi LS, Elathram N, Movva M, Deep A, Corbett KD, Debelouchina GT. Phosphorylation regulates tau's phase separation behavior and interactions with chromatin. Commun Biol 2024; 7:251. [PMID: 38429335 PMCID: PMC10907630 DOI: 10.1038/s42003-024-05920-4] [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: 12/21/2023] [Accepted: 02/16/2024] [Indexed: 03/03/2024] Open
Abstract
Tau is a microtubule-associated protein often found in neurofibrillary tangles (NFTs) in the brains of patients with Alzheimer's disease. Beyond this context, mounting evidence suggests that tau localizes into the nucleus, where it may play a role in DNA protection and heterochromatin regulation. The molecular mechanisms behind these observations are currently unclear. Using in vitro biophysical experiments, here we demonstrate that tau can undergo liquid-liquid phase separation (LLPS) with DNA, mononucleosomes, and reconstituted nucleosome arrays under low salt conditions. Low concentrations of tau promote chromatin compaction and protect DNA from digestion. While the material state of samples at physiological salt is dominated by chromatin oligomerization, tau can still associate strongly and reversibly with nucleosome arrays. These properties are driven by tau's strong interactions with linker and nucleosomal DNA. In addition, tau co-localizes into droplets formed by nucleosome arrays and phosphorylated HP1α, a key heterochromatin constituent thought to function through an LLPS mechanism. Importantly, LLPS and chromatin interactions are disrupted by aberrant tau hyperphosphorylation. These biophysical properties suggest that tau may directly impact DNA and chromatin accessibility and that loss of these interactions could contribute to the aberrant nuclear effects seen in tau pathology.
Collapse
Affiliation(s)
- Lannah S Abasi
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA, 92093, USA
| | - Nesreen Elathram
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA, 92093, USA
| | - Manasi Movva
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA, 92093, USA
| | - Amar Deep
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, CA, 92093, USA
| | - Kevin D Corbett
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, CA, 92093, USA
- Department of Molecular Biology, University of California San Diego, La Jolla, CA, 92093, USA
| | - Galia T Debelouchina
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA, 92093, USA.
| |
Collapse
|
9
|
Creekmore BC, Watanabe R, Lee EB. Neurodegenerative Disease Tauopathies. ANNUAL REVIEW OF PATHOLOGY 2024; 19:345-370. [PMID: 37832941 PMCID: PMC11009985 DOI: 10.1146/annurev-pathmechdis-051222-120750] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/15/2023]
Abstract
Tauopathies are a diverse group of progressive and fatal neurodegenerative diseases characterized by aberrant tau inclusions in the central nervous system. Tau protein forms pathologic fibrillar aggregates that are typically closely associated with neuronal cell death, leading to varied clinical phenotypes including dementia, movement disorders, and motor neuron disease. In this review, we describe the clinicopathologic features of tauopathies and highlight recent advances in understanding the mechanisms that lead to spread of pathologic aggregates through interconnected neuronal pathways. The cell-to-cell propagation of tauopathy is then linked to posttranslational modifications, tau fibril structural variants, and the breakdown of cellular protein quality control.
Collapse
Affiliation(s)
- Benjamin C Creekmore
- Translational Neuropathology Research Laboratory, Department of Pathology and Laboratory Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA;
| | - Ryohei Watanabe
- Translational Neuropathology Research Laboratory, Department of Pathology and Laboratory Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA;
| | - Edward B Lee
- Translational Neuropathology Research Laboratory, Department of Pathology and Laboratory Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA;
| |
Collapse
|
10
|
Abasi LS, Elathram N, Movva M, Deep A, Corbett KD, Debelouchina GT. Phosphorylation regulates tau's phase separation behavior and interactions with chromatin. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.21.572911. [PMID: 38187700 PMCID: PMC10769318 DOI: 10.1101/2023.12.21.572911] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2024]
Abstract
Tau is a microtubule-associated protein often found in neurofibrillary tangles (NFTs) in the brains of patients with Alzheimer's disease (AD). Beyond this context, mounting evidence suggests that tau localizes into the nucleus, where it may play a role in DNA protection and heterochromatin regulation. Models of tau depletion or pathology show loss of genetically silent heterochromatin, aberrant expression of heterochromatic genes, and transposable element activation. The molecular mechanisms behind these observations are currently unclear. Using in vitro biophysical experiments, here we demonstrate that tau can undergo liquid-liquid phase separation (LLPS) with DNA, mononucleosomes, and reconstituted nucleosome arrays under low salt conditions. Low concentrations of tau promote chromatin compaction and protect DNA from digestion. While the material state of samples at physiological salt is dominated by chromatin oligomerization, tau can still associate strongly and reversibly with nucleosome arrays. These properties are driven by tau's strong interactions with linker and nucleosomal DNA, while magic angle spinning (MAS) solid-state NMR experiments show that tau binding does not drastically alter nucleosome structure and dynamics. In addition, tau co-localizes into droplets formed by nucleosome arrays and phosphorylated HP1α, a key heterochromatin constituent thought to function through an LLPS mechanism. Importantly, LLPS and chromatin interactions are disrupted by aberrant tau hyperphosphorylation. These biophysical properties suggest that tau may directly impact DNA and chromatin accessibility and that loss of these interactions could contribute to the aberrant nuclear effects seen in tau pathology.
Collapse
Affiliation(s)
- Lannah S. Abasi
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093, USA
| | - Nesreen Elathram
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093, USA
| | - Manasi Movva
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093, USA
| | - Amar Deep
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Kevin D. Corbett
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Galia T. Debelouchina
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093, USA
| |
Collapse
|
11
|
do Amaral MJ, Mohapatra S, Passos AR, Lopes da Silva TS, Carvalho RS, da Silva Almeida M, Pinheiro AS, Wegmann S, Cordeiro Y. Copper drives prion protein phase separation and modulates aggregation. SCIENCE ADVANCES 2023; 9:eadi7347. [PMID: 37922348 PMCID: PMC10624353 DOI: 10.1126/sciadv.adi7347] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Accepted: 10/03/2023] [Indexed: 11/05/2023]
Abstract
Prion diseases are characterized by prion protein (PrP) transmissible aggregation and neurodegeneration, which has been linked to oxidative stress. The physiological function of PrP seems related to sequestering of redox-active Cu2+, and Cu2+ dyshomeostasis is observed in prion disease brain. It is unclear whether Cu2+ contributes to PrP aggregation, recently shown to be mediated by PrP condensation. This study indicates that Cu2+ promotes PrP condensation in live cells at the cell surface and in vitro through copartitioning. Molecularly, Cu2+ inhibited PrP β-structure and hydrophobic residues exposure. Oxidation, induced by H2O2, triggered liquid-to-solid transition of PrP:Cu2+ condensates and promoted amyloid-like PrP aggregation. In cells, overexpression of PrPC initially protected against Cu2+ cytotoxicity but led to PrPC aggregation upon extended copper exposure. Our data suggest that PrP condensates function as a buffer for copper that prevents copper toxicity but can transition into PrP aggregation at prolonged oxidative stress.
Collapse
Affiliation(s)
- Mariana Juliani do Amaral
- Faculdade de Farmácia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
- German Center for Neurodegenerative Diseases (DZNE), Berlin, Germany
| | | | - Aline Ribeiro Passos
- Brazilian Synchrotron Light Laboratory (LNLS), Brazilian Center for Research in Energy and Materials (CNPEM), Campinas, SP, Brazil
| | | | | | - Marcius da Silva Almeida
- Plataforma Avançada de Biomoléculas, Centro Nacional de Biologia Estrutural e Bioimagem, Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Anderson Sá Pinheiro
- Departamento de Bioquímica, Instituto de Química, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Susanne Wegmann
- German Center for Neurodegenerative Diseases (DZNE), Berlin, Germany
| | - Yraima Cordeiro
- Faculdade de Farmácia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| |
Collapse
|
12
|
Mekonnen G, Djaja N, Yuan X, Myong S. Advanced imaging techniques for studying protein phase separation in living cells and at single-molecule level. Curr Opin Chem Biol 2023; 76:102371. [PMID: 37523989 PMCID: PMC10528199 DOI: 10.1016/j.cbpa.2023.102371] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 06/04/2023] [Accepted: 06/24/2023] [Indexed: 08/02/2023]
Abstract
Protein-protein and protein-RNA interactions are essential for cell function and survival. These interactions facilitate the formation of ribonucleoprotein complexes and biomolecular condensates via phase separation. Such assembly is involved in transcription, splicing, translation and stress response. When dysregulated, proteins and RNA can undergo irreversible aggregation which can be cytotoxic and pathogenic. Despite technical advances in investigating biomolecular condensates, achieving the necessary spatiotemporal resolution to deduce the parameters that govern their assembly and behavior has been challenging. Many laboratories have applied advanced microscopy methods for imaging condensates. For example, single molecule imaging methods have enabled the detection of RNA-protein interaction, protein-protein interaction, protein conformational dynamics, and diffusional motion of molecules that report on the intrinsic molecular interactions underlying liquid-liquid phase separation. This review will outline advances in both microscopy and spectroscopy techniques which allow single molecule detection and imaging, and how these techniques can be used to probe unique aspects of biomolecular condensates.
Collapse
Affiliation(s)
- Gemechu Mekonnen
- Program in Cellular Molecular Developmental Biology and Biophysics, Johns Hopkins University, 3400 N. Charles St., Baltimore, MD 21218, USA
| | - Nathalie Djaja
- Program in Cellular Molecular Developmental Biology and Biophysics, Johns Hopkins University, 3400 N. Charles St., Baltimore, MD 21218, USA
| | - Xincheng Yuan
- Program in Cellular Molecular Developmental Biology and Biophysics, Johns Hopkins University, 3400 N. Charles St., Baltimore, MD 21218, USA
| | - Sua Myong
- Program in Cellular Molecular Developmental Biology and Biophysics, Johns Hopkins University, 3400 N. Charles St., Baltimore, MD 21218, USA; Department of Biophysics, Johns Hopkins University, 3400 N. Charles St., Baltimore, MD 21218, USA.
| |
Collapse
|
13
|
Joron K, Viegas JO, Haas-Neill L, Bier S, Drori P, Dvir S, Lim PSL, Rauscher S, Meshorer E, Lerner E. Fluorescent protein lifetimes report densities and phases of nuclear condensates during embryonic stem-cell differentiation. Nat Commun 2023; 14:4885. [PMID: 37573411 PMCID: PMC10423231 DOI: 10.1038/s41467-023-40647-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Accepted: 08/03/2023] [Indexed: 08/14/2023] Open
Abstract
Fluorescent proteins (FP) are frequently used for studying proteins inside cells. In advanced fluorescence microscopy, FPs can report on additional intracellular variables. One variable is the local density near FPs, which can be useful in studying densities within cellular bio-condensates. Here, we show that a reduction in fluorescence lifetimes of common monomeric FPs reports increased levels of local densities. We demonstrate the use of this fluorescence-based variable to report the distribution of local densities within heterochromatin protein 1α (HP1α) in mouse embryonic stem cells (ESCs), before and after early differentiation. We find that local densities within HP1α condensates in pluripotent ESCs are heterogeneous and cannot be explained by a single liquid phase. Early differentiation, however, induces a change towards a more homogeneous distribution of local densities, which can be explained as a liquid-like phase. In conclusion, we provide a fluorescence-based method to report increased local densities and apply it to distinguish between homogeneous and heterogeneous local densities within bio-condensates.
Collapse
Affiliation(s)
- Khalil Joron
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, Faculty of Mathematics & Science, The Edmond J. Safra Campus, The Hebrew University of Jerusalem, Jerusalem, 9190401, Israel
| | - Juliane Oliveira Viegas
- Department of Genetics, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem, 91904, Israel
| | - Liam Haas-Neill
- Department of Chemical and Physical Sciences, University of Toronto Mississauga, Mississauga, ON, L5L 1C6, Canada
- Department of Physics, University of Toronto, Toronto, ON, M5S 1A7, Canada
- Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, ON, M5S 3H6, Canada
| | - Sariel Bier
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, Faculty of Mathematics & Science, The Edmond J. Safra Campus, The Hebrew University of Jerusalem, Jerusalem, 9190401, Israel
- Department of Genetics, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem, 91904, Israel
| | - Paz Drori
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, Faculty of Mathematics & Science, The Edmond J. Safra Campus, The Hebrew University of Jerusalem, Jerusalem, 9190401, Israel
| | - Shani Dvir
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, Faculty of Mathematics & Science, The Edmond J. Safra Campus, The Hebrew University of Jerusalem, Jerusalem, 9190401, Israel
| | - Patrick Siang Lin Lim
- Department of Genetics, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem, 91904, Israel
| | - Sarah Rauscher
- Department of Chemical and Physical Sciences, University of Toronto Mississauga, Mississauga, ON, L5L 1C6, Canada
- Department of Physics, University of Toronto, Toronto, ON, M5S 1A7, Canada
- Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, ON, M5S 3H6, Canada
| | - Eran Meshorer
- Department of Genetics, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem, 91904, Israel.
- Edmond and Lily Center for Brain Sciences (ELSC), The Hebrew University of Jerusalem, Jerusalem, 91904, Israel.
| | - Eitan Lerner
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, Faculty of Mathematics & Science, The Edmond J. Safra Campus, The Hebrew University of Jerusalem, Jerusalem, 9190401, Israel.
- The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem, 9190401, Israel.
| |
Collapse
|
14
|
Cordeiro Y, Freire MHO, Wiecikowski AF, do Amaral MJ. (Dys)functional insights into nucleic acids and RNA-binding proteins modulation of the prion protein and α-synuclein phase separation. Biophys Rev 2023; 15:577-589. [PMID: 37681103 PMCID: PMC10480379 DOI: 10.1007/s12551-023-01067-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Accepted: 05/22/2023] [Indexed: 09/09/2023] Open
Abstract
Prion diseases are prototype of infectious diseases transmitted by a protein, the prion protein (PrP), and are still not understandable at the molecular level. Heterogenous species of aggregated PrP can be generated from its monomer. α-synuclein (αSyn), related to Parkinson's disease, has also shown a prion-like pathogenic character, and likewise PrP interacts with nucleic acids (NAs), which in turn modulate their aggregation. Recently, our group and others have characterized that NAs and/or RNA-binding proteins (RBPs) modulate recombinant PrP and/or αSyn condensates formation, and uncontrolled condensation might precede pathological aggregation. Tackling abnormal phase separation of neurodegenerative disease-related proteins has been proposed as a promising therapeutic target. Therefore, understanding the mechanism by which polyanions, like NAs, modulate phase transitions intracellularly, is key to assess their role on toxicity promotion and neuronal death. Herein we discuss data on the nucleic acids binding properties and phase separation ability of PrP and αSyn with a special focus on their modulation by NAs and RBPs. Furthermore, we provide insights into condensation of PrP and/or αSyn in the light of non-trivial subcellular locations such as the nuclear and cytosolic environments.
Collapse
Affiliation(s)
- Yraima Cordeiro
- Faculty of Pharmacy, Universidade Federal do Rio de Janeiro, Av Carlos Chagas Filho 373, bloco B, subsolo Sala 36, Rio de Janeiro, RJ 21941-902 Brazil
| | - Maria Heloisa O. Freire
- Faculty of Pharmacy, Universidade Federal do Rio de Janeiro, Av Carlos Chagas Filho 373, bloco B, subsolo Sala 36, Rio de Janeiro, RJ 21941-902 Brazil
| | - Adalgisa Felippe Wiecikowski
- Faculty of Pharmacy, Universidade Federal do Rio de Janeiro, Av Carlos Chagas Filho 373, bloco B, subsolo Sala 36, Rio de Janeiro, RJ 21941-902 Brazil
| | - Mariana Juliani do Amaral
- Faculty of Pharmacy, Universidade Federal do Rio de Janeiro, Av Carlos Chagas Filho 373, bloco B, subsolo Sala 36, Rio de Janeiro, RJ 21941-902 Brazil
| |
Collapse
|
15
|
Hurtle BT, Xie L, Donnelly CJ. Disrupting pathologic phase transitions in neurodegeneration. J Clin Invest 2023; 133:e168549. [PMID: 37395272 DOI: 10.1172/jci168549] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/04/2023] Open
Abstract
Solid-like protein deposits found in aged and diseased human brains have revealed a relationship between insoluble protein accumulations and the resulting deficits in neurologic function. Clinically diverse neurodegenerative diseases, including Alzheimer's disease, Parkinson's disease, frontotemporal lobar degeneration, and amyotrophic lateral sclerosis, exhibit unique and disease-specific biochemical protein signatures and abnormal protein depositions that often correlate with disease pathogenesis. Recent evidence indicates that many pathologic proteins assemble into liquid-like protein phases through the highly coordinated process of liquid-liquid phase separation. Over the last decade, biomolecular phase transitions have emerged as a fundamental mechanism of cellular organization. Liquid-like condensates organize functionally related biomolecules within the cell, and many neuropathology-associated proteins reside within these dynamic structures. Thus, examining biomolecular phase transitions enhances our understanding of the molecular mechanisms mediating toxicity across diverse neurodegenerative diseases. This Review explores the known mechanisms contributing to aberrant protein phase transitions in neurodegenerative diseases, focusing on tau and TDP-43 proteinopathies and outlining potential therapeutic strategies to regulate these pathologic events.
Collapse
Affiliation(s)
- Bryan T Hurtle
- Center for Neuroscience at the University of Pittsburgh Graduate Program
- Medical Scientist Training Program, University of Pittsburgh; and
- LiveLikeLou Center for ALS Research at the University of Pittsburgh Brain Institute; Pittsburgh, Pennsylvania, USA
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Longxin Xie
- LiveLikeLou Center for ALS Research at the University of Pittsburgh Brain Institute; Pittsburgh, Pennsylvania, USA
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
- School of Medicine, Tsinghua University, Beijing, China
| | - Christopher J Donnelly
- Center for Neuroscience at the University of Pittsburgh Graduate Program
- Medical Scientist Training Program, University of Pittsburgh; and
- LiveLikeLou Center for ALS Research at the University of Pittsburgh Brain Institute; Pittsburgh, Pennsylvania, USA
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| |
Collapse
|
16
|
Moreira GG, Gomes CM. Tau liquid-liquid phase separation is modulated by the Ca 2+ -switched chaperone activity of the S100B protein. J Neurochem 2023; 166:76-86. [PMID: 36621842 DOI: 10.1111/jnc.15756] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Revised: 12/03/2022] [Accepted: 12/19/2022] [Indexed: 01/10/2023]
Abstract
Aggregation of the microtubule-associated protein tau is implicated in several neurodegenerative tauopathies including Alzheimer's disease (AD). Recent studies evidenced tau liquid-liquid phase separation (LLPS) into droplets as an early event in tau pathogenesis with the potential to enhance aggregation. Tauopathies like AD are accompanied by sustained neuroinflammation and the release of alarmins at early stages of inflammatory responses encompass protective functions. The Ca2+ -binding S100B protein is an alarmin augmented in AD that was recently implicated as a proteostasis regulator acting as a chaperone-type protein, inhibiting aggregation and toxicity through interactions of amyloidogenic clients with a regulatory surface exposed upon Ca2+ -binding. Here we expand the regulatory functions of S100B over protein condensation phenomena by reporting its Ca2+ -dependent activity as a modulator of tau LLPS induced by crowding agents (PEG) and metal ions (Zn2+ ). We observe that apo S100B has a negligible effect on PEG-induced tau demixing but that Ca2+ -bound S100B prevents demixing, resulting in a shift of the phase diagram boundary to higher crowding concentrations. Also, while incubation with apo S100B does not compromise tau LLPS, addition of Ca2+ results in a sharp decrease in turbidity, indicating that interactions with S100B-Ca2+ promote transition of tau to the mixed phase. Further, electrophoretic analysis and FLIM-FRET studies revealed that S100B incorporates into tau liquid droplets, suggesting an important stabilizing and chaperoning role contributing to minimize toxic tau aggregates. Resorting to Alexa488-labeled tau we observed that S100B-Ca2+ reduces the formation of tau fluorescent droplets, without compromising liquid-like behavior and droplet fusion events. The Zn2+ -binding properties of S100B also contribute to regulate Zn2+ -promoted tau LLPS as droplets are decreased by Zn2+ buffering by S100B, in addition to the Ca2+ -triggered interactions with tau. Altogether this work uncovers the versatility of S100B as a proteostasis regulator acting on protein condensation phenomena of relevance across the neurodegeneration continuum.
Collapse
Affiliation(s)
- Guilherme G Moreira
- BioISI-Instituto de Biosistemas e Ciências Integrativas, Faculdade de Ciências, Universidade de Lisboa, Lisbon, Portugal
- Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade de Lisboa, Lisbon, Portugal
| | - Cláudio M Gomes
- BioISI-Instituto de Biosistemas e Ciências Integrativas, Faculdade de Ciências, Universidade de Lisboa, Lisbon, Portugal
- Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade de Lisboa, Lisbon, Portugal
| |
Collapse
|
17
|
Boyko S, Surewicz WK. Domain-specific modulatory effects of phosphomimetic substitutions on liquid-liquid phase separation of tau protein. J Biol Chem 2023; 299:104722. [PMID: 37075845 PMCID: PMC10199205 DOI: 10.1016/j.jbc.2023.104722] [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: 12/03/2022] [Revised: 04/04/2023] [Accepted: 04/11/2023] [Indexed: 04/21/2023] Open
Abstract
Aggregation of tau is one of the major pathogenic events in Alzheimer's disease and several other neurodegenerative disorders. Recent reports demonstrated that tau can condense into liquid droplets that undergo time-dependent transition to a solid-like state, suggesting that liquid condensates may be on the pathway to pathological aggregation of tau. While hyperphosphorylation is a key feature of tau isolated from brains of patients with Alzheimer's disease and other tauopathies, the mechanistic role of phosphorylation in tau liquid-liquid phase separation (LLPS) remains largely unexplored. In an attempt to bridge this gap, here we performed systematic studies by introducing phosphomimetic substitutions of Ser/Thr residues with negatively charged Asp/Glu residues in different regions of the protein. Our data indicate that the phosphorylation patterns that increase the polarization of charge distribution in full-length tau (tau441) promote protein LLPS, whereas those that decrease charge polarization have an opposite effect. Overall, this study further supports the notion that tau LLPS is driven by attractive intermolecular electrostatic interactions between the oppositely charged domains. We also show that the phosphomimetic tau variants with low intrinsic propensity for LLPS can be efficiently recruited to droplets formed by the variants with high LLPS propensity. Furthermore, the present data demonstrate that phosphomimetic substitutions have a major effect on time-dependent material properties of tau droplets, generally slowing down their aging. The latter effect is most dramatic for the tau variant with substitutions within the repeat domain, which correlates with the decreased fibrillation rate of this variant.
Collapse
Affiliation(s)
- Solomiia Boyko
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio, USA
| | - Witold K Surewicz
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio, USA.
| |
Collapse
|
18
|
Li P, Chen J, Wang X, Su Z, Gao M, Huang Y. Liquid - liquid phase separation of tau: Driving forces, regulation, and biological implications. Neurobiol Dis 2023; 183:106167. [PMID: 37230179 DOI: 10.1016/j.nbd.2023.106167] [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: 03/26/2023] [Revised: 05/16/2023] [Accepted: 05/21/2023] [Indexed: 05/27/2023] Open
Abstract
The past 15 years have witnessed an explosion in the studies of biomolecular condensates that are implicated in numerous biological processes and play vital roles in human health and diseases. Recent findings demonstrate that the microtubule-associated protein tau forms liquid condensates through liquid-liquid phase separation (LLPS) in in vitro experiments using purified recombinant proteins and cell-based experiments. Although in vivo studies are lacking, liquid condensates have emerged as an important assembly state of physiological and pathological tau and LLPS can regulate the function of microtubules, mediate stress granule formation, and accelerate tau amyloid aggregation. In this review, we summarize recent advances in tau LLPS, aiming to unveiling the delicate interactions driving tau LLPS. We further discuss the association of tau LLPS with physiology and disease in the context of the sophisticated regulation of tau LLPS. Deciphering the mechanisms underlying tau LLPS and the liquid-to-solid transition enables rational design of molecules that inhibit or delay the formation of tau solid species, thus providing novel targeted therapeutic strategies for tauopathies.
Collapse
Affiliation(s)
- Ping Li
- Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), Hubei University of Technology, Wuhan 430068, China; Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan 430068, China; Key Laboratory of Industrial Fermentation (Ministry of Education), Hubei University of Technology, Wuhan 430068, China
| | - Jingxin Chen
- Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), Hubei University of Technology, Wuhan 430068, China; Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan 430068, China; Key Laboratory of Industrial Fermentation (Ministry of Education), Hubei University of Technology, Wuhan 430068, China
| | - Xi Wang
- Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), Hubei University of Technology, Wuhan 430068, China; Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan 430068, China; Key Laboratory of Industrial Fermentation (Ministry of Education), Hubei University of Technology, Wuhan 430068, China
| | - Zhengding Su
- Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), Hubei University of Technology, Wuhan 430068, China; Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan 430068, China; Key Laboratory of Industrial Fermentation (Ministry of Education), Hubei University of Technology, Wuhan 430068, China
| | - Meng Gao
- Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), Hubei University of Technology, Wuhan 430068, China; Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan 430068, China; Key Laboratory of Industrial Fermentation (Ministry of Education), Hubei University of Technology, Wuhan 430068, China.
| | - Yongqi Huang
- Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), Hubei University of Technology, Wuhan 430068, China; Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan 430068, China; Key Laboratory of Industrial Fermentation (Ministry of Education), Hubei University of Technology, Wuhan 430068, China.
| |
Collapse
|
19
|
Donnaloja F, Limonta E, Mancosu C, Morandi F, Boeri L, Albani D, Raimondi MT. Unravelling the mechanotransduction pathways in Alzheimer's disease. J Biol Eng 2023; 17:22. [PMID: 36978103 PMCID: PMC10045049 DOI: 10.1186/s13036-023-00336-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2022] [Accepted: 03/02/2023] [Indexed: 03/30/2023] Open
Abstract
Alzheimer's disease (AD) represents one of the most common and debilitating neurodegenerative disorders. By the end of 2040, AD patients might reach 11.2 million in the USA, around 70% higher than 2022, with severe consequences on the society. As now, we still need research to find effective methods to treat AD. Most studies focused on the tau and amyloid hypothesis, but many other factors are likely involved in the pathophysiology of AD. In this review, we summarize scientific evidence dealing with the mechanotransduction players in AD to highlight the most relevant mechano-responsive elements that play a role in AD pathophysiology. We focused on the AD-related role of extracellular matrix (ECM), nuclear lamina, nuclear transport and synaptic activity. The literature supports that ECM alteration causes the lamin A increment in the AD patients, leading to the formation of nuclear blebs and invaginations. Nuclear blebs have consequences on the nuclear pore complexes, impairing nucleo-cytoplasmic transport. This may result in tau hyperphosphorylation and its consequent self-aggregation in tangles, which impairs the neurotransmitters transport. It all exacerbates in synaptic transmission impairment, leading to the characteristic AD patient's memory loss. Here we related for the first time all the evidence associating the mechanotransduction pathway with neurons. In addition, we highlighted the entire pathway influencing neurodegenerative diseases, paving the way for new research perspectives in the context of AD and related pathologies.
Collapse
Affiliation(s)
- Francesca Donnaloja
- Politecnico Di Milano, Department of Chemistry, Materials and Chemical Engineering "G. Natta", Campus Leonardo, Piazza Leonardo da Vinci 32, 20133, Milan, Italy.
| | - Emma Limonta
- Politecnico Di Milano, Department of Chemistry, Materials and Chemical Engineering "G. Natta", Campus Leonardo, Piazza Leonardo da Vinci 32, 20133, Milan, Italy
| | - Christian Mancosu
- Politecnico Di Milano, Department of Chemistry, Materials and Chemical Engineering "G. Natta", Campus Leonardo, Piazza Leonardo da Vinci 32, 20133, Milan, Italy
| | - Francesco Morandi
- Politecnico Di Milano, Department of Chemistry, Materials and Chemical Engineering "G. Natta", Campus Leonardo, Piazza Leonardo da Vinci 32, 20133, Milan, Italy
| | - Lucia Boeri
- Politecnico Di Milano, Department of Chemistry, Materials and Chemical Engineering "G. Natta", Campus Leonardo, Piazza Leonardo da Vinci 32, 20133, Milan, Italy
| | - Diego Albani
- Department of Neuroscience, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Milan, Italy
| | - Manuela Teresa Raimondi
- Politecnico Di Milano, Department of Chemistry, Materials and Chemical Engineering "G. Natta", Campus Leonardo, Piazza Leonardo da Vinci 32, 20133, Milan, Italy.
| |
Collapse
|
20
|
Hauf S, Yokobayashi Y. Chemical control of phase separation in DNA solutions. Chem Commun (Camb) 2023; 59:3751-3754. [PMID: 36911995 DOI: 10.1039/d2cc06901f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/08/2023]
Abstract
We designed a series of DNA sequences comprising a trinucleotide repeat segment and a small molecule-binding aptamer. Optimization of the DNA sequences and reaction conditions enabled chemical control of phase separation of DNA condensates. Our results demonstrate a new strategy to regulate biomolecular phase transition.
Collapse
Affiliation(s)
- Samuel Hauf
- Nucleic Acid Chemistry and Engineering Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa, Japan 904-0495, Japan.
| | - Yohei Yokobayashi
- Nucleic Acid Chemistry and Engineering Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa, Japan 904-0495, Japan.
| |
Collapse
|
21
|
Initiation and modulation of Tau protein phase separation by the drug suramin. Sci Rep 2023; 13:3963. [PMID: 36894559 PMCID: PMC9997437 DOI: 10.1038/s41598-023-29846-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Accepted: 02/10/2023] [Indexed: 03/11/2023] Open
Abstract
Tau is an intrinsically disordered neuronal protein in the central nervous system. Aggregated Tau is the main component of neurofibrillary tangles observed in Alzheimer's disease. In vitro, Tau aggregation can be triggered by polyanionic co-factors, like RNA or heparin. At different concentration ratios, the same polyanions can induce Tau condensates via liquid-liquid phase separation (LLPS), which over time develop pathological aggregation seeding potential. Data obtained by time resolved Dynamic Light Scattering experiments (trDLS), light and electron microscopy show that intermolecular electrostatic interactions between Tau and the negatively charged drug suramin induce Tau condensation and compete with the interactions driving and stabilizing the formation of Tau:heparin and Tau:RNA coacervates, thus, reducing their potential to induce cellular Tau aggregation. Tau:suramin condensates do not seed Tau aggregation in a HEK cell model for Tau aggregation, even after extended incubation. These observations indicate that electrostatically driven Tau condensation can occur without pathological aggregation when initiated by small anionic molecules. Our results provide a novel avenue for therapeutic intervention of aberrant Tau phase separation, utilizing small anionic compounds.
Collapse
|
22
|
Biomolecular condensation involving the cytoskeleton. Brain Res Bull 2023; 194:105-117. [PMID: 36690162 DOI: 10.1016/j.brainresbull.2023.01.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Revised: 01/07/2023] [Accepted: 01/19/2023] [Indexed: 01/22/2023]
Abstract
Biomolecular condensation of proteins contributes to the organization of the cytoplasm and nucleoplasm. A number of condensation processes appear to be directly involved in regulating the structure, function and dynamics of the cytoskeleton. Liquid-liquid phase separation of cytoskeleton proteins, together with polymerization modulators, promotes cytoskeletal fiber nucleation and branching. Furthermore, the attachment of protein condensates to the cytoskeleton can contribute to cytoskeleton stability and organization, regulate transport, create patterns of functional reaction containers, and connect the cytoskeleton with membranes. Surface-bound condensates can exert and buffer mechanical forces that give stability and flexibility to the cytoskeleton, thus, may play a large role in cell biology. In this review, we introduce the concept and role of cellular biomolecular condensation, explain its special function on cytoskeletal fiber surfaces, and point out potential definition and experimental caveats. We review the current literature on protein condensation processes related to the actin, tubulin, and intermediate filament cytoskeleton, and discuss some of them in the context of neurobiology. In summary, we provide an overview about biomolecular condensation in relation to cytoskeleton structure and function, which offers a base for the exploration and interpretation of cytoskeletal condensates in neurobiology.
Collapse
|
23
|
Ainani H, Bouchmaa N, Ben Mrid R, El Fatimy R. Liquid-liquid phase separation of protein tau: An emerging process in Alzheimer's disease pathogenesis. Neurobiol Dis 2023; 178:106011. [PMID: 36702317 DOI: 10.1016/j.nbd.2023.106011] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2022] [Revised: 01/04/2023] [Accepted: 01/21/2023] [Indexed: 01/24/2023] Open
Abstract
Metabolic reactions within cells occur in various isolated compartments with or without borders, the latter being known as membrane-less organelles (MLOs). The MLOs show liquid-like properties and are formed by a process known as liquid-liquid phase separation (LLPS). MLOs contribute to different molecules interactions such as protein-protein, protein-RNA, and RNA-RNA driven by various factors, such as multivalency of intrinsic disorders. MLOs are involved in several cell signaling pathways such as transcription, immune response, and cellular organization. However, disruption of these processes has been found in different pathologies. Recently, it has been demonstrated that protein aggregates, a characteristic of some neurodegenerative diseases, undergo similar phase separation. Tau protein is known as a major neurofibrillary tangles component in Alzheimer's disease (AD). This protein can undergo phase separation to form a MLO known as tau droplet in vitro and in vivo, and this process can be facilitated by several factors, including crowding agents, RNA, and phosphorylation. Tau droplet has been shown to mature into insoluble aggregates suggesting that this process may precede and induce neurodegeneration in AD. Here we review major factors involved in liquid droplet formation within a cell. Additionally, we highlight recent findings concerning tau aggregation following phase separation in AD, along with the potential therapeutic strategies that could be explored in this process against the progression of this pathology.
Collapse
Affiliation(s)
- Hassan Ainani
- Institute of Biological Sciences (ISSB), UM6P-Faculty of Medical Sciences (UM6P-FMS), Mohammed VI Polytechnic University, Ben-Guerir, Morocco
| | - Najat Bouchmaa
- Institute of Biological Sciences (ISSB), UM6P-Faculty of Medical Sciences (UM6P-FMS), Mohammed VI Polytechnic University, Ben-Guerir, Morocco
| | - Reda Ben Mrid
- Institute of Biological Sciences (ISSB), UM6P-Faculty of Medical Sciences (UM6P-FMS), Mohammed VI Polytechnic University, Ben-Guerir, Morocco
| | - Rachid El Fatimy
- Institute of Biological Sciences (ISSB), UM6P-Faculty of Medical Sciences (UM6P-FMS), Mohammed VI Polytechnic University, Ben-Guerir, Morocco.
| |
Collapse
|
24
|
Chen J, Ma W, Yu J, Wang X, Qian H, Li P, Ye H, Han Y, Su Z, Gao M, Huang Y. (-)-Epigallocatechin-3-gallate, a Polyphenol from Green Tea, Regulates the Liquid-Liquid Phase Separation of Alzheimer's-Related Protein Tau. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2023; 71:1982-1993. [PMID: 36688583 DOI: 10.1021/acs.jafc.2c07799] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
The microtubule-associated protein tau is involved in Alzheimer's disease and other tauopathies. Recently, tau has been shown to undergo liquid-liquid phase separation (LLPS), which is implicated in the physiological function and pathological aggregation of tau. In this report, we demonstrate that the green tea polyphenol (-)-epigallocatechin-3-gallate (EGCG) promotes the formation of liquid tau droplets at neutral pH by creating a network of hydrophobic interactions and hydrogen bonds, mainly with the proline-rich domain of tau. We further show that EGCG oxidation, tau phosphorylation, and the chemical structure of the polyphenol influence the efficacy of EGCG in facilitating tau LLPS. Complementary to the inhibitory activity of EGCG in tau fibrillization, our findings provide novel insights into the biological activity of EGCG and offer new clues for future studies on the molecular mechanism by which EGCG alleviates neurodegenerative diseases.
Collapse
Affiliation(s)
- Jingxin Chen
- Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), Key Laboratory of Industrial Fermentation (Ministry of Education), and Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan 430068, China
| | - Wanyao Ma
- Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), Key Laboratory of Industrial Fermentation (Ministry of Education), and Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan 430068, China
| | - Jiangchuan Yu
- Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), Key Laboratory of Industrial Fermentation (Ministry of Education), and Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan 430068, China
| | - Xi Wang
- Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), Key Laboratory of Industrial Fermentation (Ministry of Education), and Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan 430068, China
| | - Hongling Qian
- Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), Key Laboratory of Industrial Fermentation (Ministry of Education), and Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan 430068, China
| | - Ping Li
- Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), Key Laboratory of Industrial Fermentation (Ministry of Education), and Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan 430068, China
| | - Haiqiong Ye
- Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), Key Laboratory of Industrial Fermentation (Ministry of Education), and Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan 430068, China
| | - Yue Han
- Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), Key Laboratory of Industrial Fermentation (Ministry of Education), and Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan 430068, China
| | - Zhengding Su
- Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), Key Laboratory of Industrial Fermentation (Ministry of Education), and Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan 430068, China
| | - Meng Gao
- Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), Key Laboratory of Industrial Fermentation (Ministry of Education), and Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan 430068, China
| | - Yongqi Huang
- Cooperative Innovation Center of Industrial Fermentation (Ministry of Education & Hubei Province), Key Laboratory of Industrial Fermentation (Ministry of Education), and Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan 430068, China
| |
Collapse
|
25
|
Lester E, Van Alstyne M, McCann KL, Reddy S, Cheng LY, Kuo J, Pratt J, Parker R. Cytosolic condensates rich in polyserine define subcellular sites of tau aggregation. Proc Natl Acad Sci U S A 2023; 120:e2217759120. [PMID: 36626563 PMCID: PMC9934293 DOI: 10.1073/pnas.2217759120] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Accepted: 12/06/2022] [Indexed: 01/11/2023] Open
Abstract
Tau aggregates are a hallmark of multiple neurodegenerative diseases and can contain RNAs and RNA-binding proteins, including serine/arginine repetitive matrix protein 2 (SRRM2) and pinin (PNN). However, how these nuclear proteins mislocalize and their influence on the prion-like propagation of tau aggregates is unknown. We demonstrate that polyserine repeats in SRRM2 and PNN are necessary and sufficient for recruitment to tau aggregates. Moreover, we show tau aggregates preferentially grow in association with endogenous cytoplasmic assemblies-mitotic interchromatin granules and cytoplasmic speckles (CSs)-which contain SRRM2 and PNN. Polyserine overexpression in cells nucleates assemblies that are sites of tau aggregate growth. Further, modulating the levels of polyserine-containing proteins results in a corresponding change in tau aggregation. These findings define a specific protein motif, and cellular condensates, that promote tau aggregate propagation. As CSs form in induced pluripotent stem cell (iPSC) derived neurons under inflammatory or hyperosmolar stress, they may affect tau aggregate propagation in neurodegenerative disease.
Collapse
Affiliation(s)
- Evan Lester
- Medical Scientist Training Program, University of Colorado Anschutz Medical Campus, Aurora, CO80045
- Department of Biochemistry, University of Colorado, Boulder, CO80303
| | - Meaghan Van Alstyne
- Department of Biochemistry, University of Colorado, Boulder, CO80303
- HHMI, University of Colorado, Boulder, CO80303
| | - Kathleen L. McCann
- Department of Biochemistry, University of Colorado, Boulder, CO80303
- HHMI, University of Colorado, Boulder, CO80303
| | - Spoorthy Reddy
- Department of Biochemistry, University of Colorado, Boulder, CO80303
| | - Li Yi Cheng
- Department of Biochemistry, University of Colorado, Boulder, CO80303
| | - Jeff Kuo
- Department of Biochemistry, University of Colorado, Boulder, CO80303
| | - James Pratt
- Department of Biochemistry, University of Colorado, Boulder, CO80303
| | - Roy Parker
- Department of Biochemistry, University of Colorado, Boulder, CO80303
- HHMI, University of Colorado, Boulder, CO80303
| |
Collapse
|
26
|
Konietzny A, Wegmann S, Mikhaylova M. The endoplasmic reticulum puts a new spin on synaptic tagging. Trends Neurosci 2023; 46:32-44. [PMID: 36428191 DOI: 10.1016/j.tins.2022.10.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Revised: 10/12/2022] [Accepted: 10/31/2022] [Indexed: 11/23/2022]
Abstract
The heterogeneity of the endoplasmic reticulum (ER) makes it a versatile platform for a broad range of homeostatic processes, ranging from calcium regulation to synthesis and trafficking of proteins and lipids. It is not surprising that neurons use this organelle to fine-tune synaptic properties and thereby provide specificity to synaptic inputs. In this review, we discuss the mechanisms that enable activity-dependent ER recruitment into dendritic spines, with a focus on molecular mechanisms that mediate transport and retention of the ER in spines. The role of calcium signaling in spine ER, synaptopodin 'tagging' of active synapses, and the formation of the spine apparatus (SA) are highlighted. Finally, we discuss the role of liquid-liquid phase separation as a possible driving force in these processes.
Collapse
Affiliation(s)
- Anja Konietzny
- AG Optobiology, Institute of Biology, Humboldt Universität zu Berlin, Berlin, Germany; Guest Group 'Neuronal Protein Transport', Center for Molecular Neurobiology, ZMNH, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Susanne Wegmann
- German Center for Neurodegenerative Diseases (DZNE), Berlin, Germany
| | - Marina Mikhaylova
- AG Optobiology, Institute of Biology, Humboldt Universität zu Berlin, Berlin, Germany; Guest Group 'Neuronal Protein Transport', Center for Molecular Neurobiology, ZMNH, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
| |
Collapse
|
27
|
Di Liegro CM, Schiera G, Schirò G, Di Liegro I. RNA-Binding Proteins as Epigenetic Regulators of Brain Functions and Their Involvement in Neurodegeneration. Int J Mol Sci 2022; 23:ijms232314622. [PMID: 36498959 PMCID: PMC9739182 DOI: 10.3390/ijms232314622] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Revised: 11/18/2022] [Accepted: 11/22/2022] [Indexed: 11/25/2022] Open
Abstract
A central aspect of nervous system development and function is the post-transcriptional regulation of mRNA fate, which implies time- and site-dependent translation, in response to cues originating from cell-to-cell crosstalk. Such events are fundamental for the establishment of brain cell asymmetry, as well as of long-lasting modifications of synapses (long-term potentiation: LTP), responsible for learning, memory, and higher cognitive functions. Post-transcriptional regulation is in turn dependent on RNA-binding proteins that, by recognizing and binding brief RNA sequences, base modifications, or secondary/tertiary structures, are able to control maturation, localization, stability, and translation of the transcripts. Notably, most RBPs contain intrinsically disordered regions (IDRs) that are thought to be involved in the formation of membrane-less structures, probably due to liquid-liquid phase separation (LLPS). Such structures are evidenced as a variety of granules that contain proteins and different classes of RNAs. The other side of the peculiar properties of IDRs is, however, that, under altered cellular conditions, they are also prone to form aggregates, as observed in neurodegeneration. Interestingly, RBPs, as part of both normal and aggregated complexes, are also able to enter extracellular vesicles (EVs), and in doing so, they can also reach cells other than those that produced them.
Collapse
Affiliation(s)
- Carlo Maria Di Liegro
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (Dipartimento di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche) (STEBICEF), University of Palermo, 90128 Palermo, Italy
| | - Gabriella Schiera
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (Dipartimento di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche) (STEBICEF), University of Palermo, 90128 Palermo, Italy
| | - Giuseppe Schirò
- Department of Biomedicine, Neurosciences and Advanced Diagnostics (Dipartimento di Biomedicina, Neuroscienze e Diagnostica Avanzata) (Bi.N.D.), University of Palermo, 90127 Palermo, Italy
| | - Italia Di Liegro
- Department of Biomedicine, Neurosciences and Advanced Diagnostics (Dipartimento di Biomedicina, Neuroscienze e Diagnostica Avanzata) (Bi.N.D.), University of Palermo, 90127 Palermo, Italy
- Correspondence: ; Tel.: +39-091-238-97 (ext. 415/446)
| |
Collapse
|
28
|
Alemasova EE, Lavrik OI. Poly(ADP-ribose) in Condensates: The PARtnership of Phase Separation and Site-Specific Interactions. Int J Mol Sci 2022; 23:14075. [PMID: 36430551 PMCID: PMC9694962 DOI: 10.3390/ijms232214075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 11/09/2022] [Accepted: 11/11/2022] [Indexed: 11/17/2022] Open
Abstract
Biomolecular condensates are nonmembrane cellular compartments whose formation in many cases involves phase separation (PS). Despite much research interest in this mechanism of macromolecular self-organization, the concept of PS as applied to a live cell faces certain challenges. In this review, we discuss a basic model of PS and the role of site-specific interactions and percolation in cellular PS-related events. Using a multivalent poly(ADP-ribose) molecule as an example, which has high PS-driving potential due to its structural features, we consider how site-specific interactions and network formation are involved in the formation of phase-separated cellular condensates.
Collapse
Affiliation(s)
- Elizaveta E. Alemasova
- Institute of Chemical Biology and Fundamental Medicine, SB RAS, Novosibirsk 630090, Russia
| | - Olga I. Lavrik
- Institute of Chemical Biology and Fundamental Medicine, SB RAS, Novosibirsk 630090, Russia
- Department of Natural Sciences, Novosibirsk State University, Novosibirsk 630090, Russia
| |
Collapse
|
29
|
A Novel Tandem-Tag Purification Strategy for Challenging Disordered Proteins. Biomolecules 2022; 12:biom12111566. [DOI: 10.3390/biom12111566] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 10/17/2022] [Accepted: 10/18/2022] [Indexed: 11/16/2022] Open
Abstract
Intrinsically disordered proteins (IDPs) lack well-defined 3D structures and can only be described as ensembles of different conformations. This high degree of flexibility allows them to interact promiscuously and makes them capable of fulfilling unique and versatile regulatory roles in cellular processes. These functional benefits make IDPs widespread in nature, existing in every living organism from bacteria and fungi to plants and animals. Due to their open and exposed structural state, IDPs are much more prone to proteolytic degradation than their globular counterparts. Therefore, the purification of recombinant IDPs requires extra care and caution, such as maintaining low temperature throughout the purification, the use of protease inhibitor cocktails and fast workflow. Even so, in the case of long IDP targets, the appearance of truncated by-products often seems unavoidable. The separation of these unwanted proteins can be very challenging due to their similarity to the parent target protein. Here, we describe a tandem-tag purification method that offers a remedy to this problem. It contains only common affinity-chromatography steps (HisTrap and Heparin) to ensure low cost, easy access and scaling-up for possible industrial use. The effectiveness of the method is demonstrated with four examples, Tau-441 and two of its fragments and the transactivation domain (AF1) of androgen receptor.
Collapse
|
30
|
Wiersma VI, Rigort R, Polymenidou M. Tau: a phase in the crowd. EMBO J 2022; 41:e111425. [PMID: 35578810 PMCID: PMC9156963 DOI: 10.15252/embj.2022111425] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Accepted: 04/28/2022] [Indexed: 11/09/2022] Open
Abstract
From the management of microtubules to the production of pathological species: liquid-liquid phase separation may tune the behavior of the protein tau in health and neurodegenerative disease. In this issue of The EMBO Journal, Hochmair et al (2022) demystify important aspects of tau condensate compilation.
Collapse
Affiliation(s)
- Vera I Wiersma
- Department of Quantitative BiomedicineUniversity of ZurichZurichSwitzerland
| | - Ruben Rigort
- Department of Quantitative BiomedicineUniversity of ZurichZurichSwitzerland
| | | |
Collapse
|
31
|
Diez L, Kapinos LE, Hochmair J, Huebschmann S, Dominguez-Baquero A, Vogt A, Rankovic M, Zweckstetter M, Lim RYH, Wegmann S. Phosphorylation but Not Oligomerization Drives the Accumulation of Tau with Nucleoporin Nup98. Int J Mol Sci 2022; 23:3495. [PMID: 35408855 PMCID: PMC8998617 DOI: 10.3390/ijms23073495] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Revised: 03/19/2022] [Accepted: 03/21/2022] [Indexed: 02/04/2023] Open
Abstract
Tau is a neuronal protein that stabilizes axonal microtubules (MTs) in the central nervous system. In Alzheimer's disease (AD) and other tauopathies, phosphorylated Tau accumulates in intracellular aggregates, a pathological hallmark of these diseases. However, the chronological order of pathological changes in Tau prior to its cytosolic aggregation remains unresolved. These include its phosphorylation and detachment from MTs, mislocalization into the somatodendritic compartment, and oligomerization in the cytosol. Recently, we showed that Tau can interact with phenylalanine-glycine (FG)-rich nucleoporins (Nups), including Nup98, that form a diffusion barrier inside nuclear pore complexes (NPCs), leading to defects in nucleocytoplasmic transport. Here, we used surface plasmon resonance (SPR) and bio-layer interferometry (BLI) to investigate the molecular details of Tau:Nup98 interactions and determined how Tau phosphorylation and oligomerization impact the interactions. Importantly, phosphorylation, but not acetylation, strongly facilitates the accumulation of Tau with Nup98. Oligomerization, however, seems to inhibit Tau:Nup98 interactions, suggesting that Tau-FG Nup interactions occur prior to oligomerization. Overall, these results provide fundamental insights into the molecular mechanisms of Tau-FG Nup interactions within NPCs, which might explain how stress-and disease-associated posttranslational modifications (PTMs) may lead to Tau-induced nucleocytoplasmic transport (NCT) failure. Intervention strategies that could rescue Tau-induced NCT failure in AD and tauopathies will be further discussed.
Collapse
Affiliation(s)
- Lisa Diez
- German Center for Neurodegenerative Diseases (DZNE), Charitéplatz 1, 10117 Berlin, Germany; (L.D.); (J.H.); (S.H.); (A.D.-B.); (A.V.)
| | - Larisa E. Kapinos
- Biozentrum and the Swiss Nanoscience Institute, University of Basel, 4056 Basel, Switzerland; (L.E.K.); (R.Y.H.L.)
| | - Janine Hochmair
- German Center for Neurodegenerative Diseases (DZNE), Charitéplatz 1, 10117 Berlin, Germany; (L.D.); (J.H.); (S.H.); (A.D.-B.); (A.V.)
| | - Sabrina Huebschmann
- German Center for Neurodegenerative Diseases (DZNE), Charitéplatz 1, 10117 Berlin, Germany; (L.D.); (J.H.); (S.H.); (A.D.-B.); (A.V.)
| | - Alvaro Dominguez-Baquero
- German Center for Neurodegenerative Diseases (DZNE), Charitéplatz 1, 10117 Berlin, Germany; (L.D.); (J.H.); (S.H.); (A.D.-B.); (A.V.)
| | - Amelie Vogt
- German Center for Neurodegenerative Diseases (DZNE), Charitéplatz 1, 10117 Berlin, Germany; (L.D.); (J.H.); (S.H.); (A.D.-B.); (A.V.)
| | - Marija Rankovic
- Max Planck Institute for Multidisciplinary Sciences, Am Fassberg 11, 37077 Goettingen, Germany; (M.R.); (M.Z.)
| | - Markus Zweckstetter
- Max Planck Institute for Multidisciplinary Sciences, Am Fassberg 11, 37077 Goettingen, Germany; (M.R.); (M.Z.)
- German Center for Neurodegenerative Diseases (DZNE), Von-Siebold-Str. 3a, 37075 Goettingen, Germany
| | - Roderick Y. H. Lim
- Biozentrum and the Swiss Nanoscience Institute, University of Basel, 4056 Basel, Switzerland; (L.E.K.); (R.Y.H.L.)
| | - Susanne Wegmann
- German Center for Neurodegenerative Diseases (DZNE), Charitéplatz 1, 10117 Berlin, Germany; (L.D.); (J.H.); (S.H.); (A.D.-B.); (A.V.)
| |
Collapse
|