The liquid-to-solid transition of FUS is promoted by the condensate surface

Proceedings of the National Academy of Sciences, Journal Year: 2023, Volume and Issue: 120(33)

Published: Aug. 7, 2023

A wide range of macromolecules can undergo phase separation, forming biomolecular condensates in living cells. These membraneless organelles are typically highly dynamic, formed reversibly, and carry out essential functions biological systems. Crucially, however, a further liquid-to-solid transition the lead to irreversible pathological aggregation cellular dysfunction associated with onset development neurodegenerative diseases. Despite importance this proteins, mechanism by which it is initiated normally functional unknown. Here we show, measuring changes structure, dynamics, mechanics time space, that single-component FUS do not uniformly convert solid gel, but rather liquid gel phases coexist simultaneously within same condensate, resulting inhomogeneous structures. Furthermore, our results show originates at interface between condensate dilute continuous phase, once initiated, gelation process propagates toward center condensate. To probe such spatially rheology during aging, use combination established micropipette aspiration experiments together two optical techniques, spatial dynamic mapping reflective confocal speckle microscopy. reveal spatiotemporal dimension highlight as critical element driving protein aggregation.

Language: Английский

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Protein misfolding and amyloid nucleation through liquid–liquid phase separation

Chemical Society Reviews, Journal Year: 2024, Volume and Issue: 53(10), P. 4976 - 5013

Published: Jan. 1, 2024

Protein misfolding and amyloid aggregation, linked to neurodegenerative diseases, can result from liquid–liquid phase separation (LLPS) a subsequent liquid-to-solid transition. This represents LLPS as generic mechanism in nucleation.

Language: Английский

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Distinct tau and alpha-synuclein molecular signatures in Alzheimer’s disease with and without Lewy bodies and Parkinson’s disease with dementia

Acta Neuropathologica, Journal Year: 2024, Volume and Issue: 147(1)

Published: Jan. 10, 2024

Abstract Alpha-synuclein (aSyn) pathology is present in approximately 50% of Alzheimer’s disease (AD) cases at autopsy and might impact the age-of-onset progression AD. Here, we aimed to determine whether tau aSyn profiles differ between AD with Lewy bodies (AD-LB), pure Parkinson’s dementia (PDD) using epitope-, post-translational modification- (PTM) isoform-specific antibody panels spanning from N- C-terminus. We included middle temporal gyrus (MTG) amygdala (AMY) clinically diagnosed pathologically confirmed performed dot blotting, western blotting immunohistochemistry combined quantitative morphological analyses. All investigated phospho-tau (pTau) species, except pT181, were upregulated AD-LB compared PDD control cases, but no significant differences observed subjects. In addition, antibodies targeting proline-rich regions C-terminus showed preferential binding brain homogenates. Antibodies C-terminal epitopes pS129 stronger cases. Two pTau species (pS198 pS396) specifically detected soluble protein fractions subjects, indicative early involvement these PTMs multimerization process tau. Other phospho-variants for both (pT212/S214, pT231 pS422) (pS129) only insoluble fraction AD-LB/AD AD-LB/PDD respectively. load was higher AMY suggesting aggravated under presence pathology, while similar Co-localization could be within astrocytes MTG. These findings highlight a unique pathological signature

Language: Английский

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Chemically Informed Coarse-Graining of Electrostatic Forces in Charge-Rich Biomolecular Condensates

ACS Central Science, Journal Year: 2025, Volume and Issue: 11(2), P. 302 - 321

Published: Feb. 11, 2025

Biomolecular condensates composed of highly charged biomolecules, such as DNA, RNA, chromatin, and nucleic-acid binding proteins, are ubiquitous in the cell nucleus. The biophysical properties these charge-rich largely regulated by electrostatic interactions. Residue-resolution coarse-grained models that describe solvent ions implicitly widely used to gain mechanistic insights into condensates, offering transferability, computational efficiency, accurate predictions for multiple systems. However, their predictive accuracy diminishes due implicit treatment ions. Here, we present Mpipi-Recharged, a residue-resolution model improves description charge effects biomolecular containing disordered multidomain and/or single-stranded RNAs. Mpipi-Recharged introduces pair-specific asymmetric Yukawa potential, informed atomistic simulations. We show this coarse-graining forces captures intricate effects, blockiness, stoichiometry variations complex coacervates, modulation salt concentration, without requiring explicit solvation. provides excellent agreement with experiments predicting phase behavior condensates. Overall, tools available investigate physicochemical mechanisms regulating enhancing scope computer simulations field.

Language: Английский

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Targeting Biomolecular Condensation and Protein Aggregation against Cancer

Chemical Reviews, Journal Year: 2023, Volume and Issue: 123(14), P. 9094 - 9138

Published: June 28, 2023

Biomolecular condensates, membrane-less entities arising from liquid–liquid phase separation, hold dichotomous roles in health and disease. Alongside their physiological functions, these condensates can transition to a solid phase, producing amyloid-like structures implicated degenerative diseases cancer. This review thoroughly examines the dual nature of biomolecular spotlighting role cancer, particularly concerning p53 tumor suppressor. Given that over half malignant tumors possess mutations TP53 gene, this topic carries profound implications for future cancer treatment strategies. Notably, not only misfolds but also forms aggregates analogous other protein-based amyloids, thus significantly influencing progression through loss-of-function, negative dominance, gain-of-function pathways. The exact molecular mechanisms underpinning mutant remain elusive. However, cofactors like nucleic acids glycosaminoglycans are known be critical players intersection between diseases. Importantly, we reveal molecules capable inhibiting aggregation curtail proliferation migration. Hence, targeting transitions solid-like amorphous states offers promising direction innovative diagnostics therapeutics.

Language: Английский

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Time-Dependent Material Properties of Aging Biomolecular Condensates from Different Viscoelasticity Measurements in Molecular Dynamics Simulations

The Journal of Physical Chemistry B, Journal Year: 2023, Volume and Issue: 127(20), P. 4441 - 4459

Published: May 17, 2023

Biomolecular condensates are important contributors to the internal organization of cell material. While initially described as liquid-like droplets, term biomolecular is now used describe a diversity condensed phase assemblies with material properties extending from low high viscous liquids, gels, and even glasses. Because determined by intrinsic behavior their molecules, characterizing such integral rationalizing molecular mechanisms that dictate functions roles in health disease. Here, we apply compare three distinct computational methods measure viscoelasticity simulations. These Green–Kubo (GK) relation, oscillatory shear (OS) technique, bead tracking (BT) method. We find that, although all these provide consistent results for viscosity condensates, GK OS techniques outperform BT method terms efficiency statistical uncertainty. thus set 12 different protein/RNA systems using sequence-dependent coarse-grained model. Our reveal strong correlation between condensate density, well length number stickers vs spacers amino acid protein sequence. Moreover, couple technique nonequilibrium dynamics simulations mimic progressive liquid-to-gel transition due accumulation interprotein β-sheets. i.e., those formed either hnRNPA1, FUS, or TDP-43 proteins, whose transitions associated onset amyotrophic lateral sclerosis frontotemporal dementia. both successfully predict functional kinetically arrested states once network β-sheets has percolated through condensates. Overall, our work provides comparison modeling rheological assess critical magnitude information on biomolecules inside

Language: Английский

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Liquid-Droplet-Mediated ATP-Triggered Amyloidogenic Pathway of Insulin-Derived Chimeric Peptides: Unraveling the Microscopic and Molecular Processes

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(7), P. 4177 - 4186

Published: Feb. 10, 2023

Disease-associated progression of protein dysfunction is typically determined by an interplay transition pathways leading to liquid–liquid phase separation (LLPS) and amyloid fibrils. As LLPS introduces another layer complexity into fibrillization metastable proteins, a need for tunable model systems study these intertwined processes has emerged. Here, we demonstrate the LLPS/fibrillization properties family chimeric peptides, ACC1–13Kn, in which highly amyloidogenic fragment insulin (ACC1–13) merged with oligolysine segments various lengths (Kn, n = 8, 16, 24, 32, 40). ACC1–13Kn are triggered ATP through Coulombic interactions Kn fragments. ACC1–13K8 ACC1–13K16 form fibrils after short lag without any evidence LLPS. However, case three longest triggers instantaneous followed disappearance droplets occurring in-phase formation The kinetics stability mature co-aggregates sensitive ionic strength, indicating that electrostatic play pivotal role selecting LLPS-fibrillization pathway. Densely packed characterize ACC1–13Kn–ATP render them hydrostatic pressure due solvent electrostriction, as demonstrated infrared spectroscopy. Using atomic force microscopy imaging rapidly frozen samples, early within single liquid droplets, starting at droplet/bulk interface bent fibers. A hypothetical molecular scenario underlying emergence LLPS-to-fibrils pathway system been put forward.

Language: Английский

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From a Droplet to a Fibril and from a Fibril to a Droplet: Intertwined Transition Pathways in Highly Dynamic Enzyme-Modulated Peptide-Adenosine Triphosphate Systems

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(9), P. 6045 - 6052

Published: Feb. 23, 2024

Many cellular coassemblies of proteins and polynucleotides facilitate liquid–liquid phase separation (LLPS) the subsequent self-assembly disease-associated amyloid fibrils within liquid droplets. Here, we explore dynamics coupled conformational transitions model adenosine triphosphate (ATP)-binding peptides, ACC1–13Kn, consisting potent amyloidogenic fragment insulin's A-chain (ACC1–13) merged with oligolysine segments various lengths (Kn, n = 16, 24, 40). The ATP-stabilized is preceded by LLPS for peptides sufficiently long segments. two-component droplets are in dynamic equilibria free ATP monomeric which makes them susceptible to ATP-hydrolyzing apyrase ACC1–13Kn-digesting proteinase K. Both enzymes capable rapid disassembly fibrils, producing either monomers peptide (apyrase) or released together cleaved-off (proteinase K). In latter case, enzyme-sequestered Kn form co-released ATP, resulting an unusual fibril-to-droplet transition. support highly nature aggregate-monomer equilibria, addition superstoichiometric amounts ACC1–13Kn-ATP coaggregate causes its disassembly. Our results show that droplet state not merely intermediate on pathway aggregate but may also constitute final a complex protein misfolding scenario rich degraded fragments incompetent transition again into fibrils.

Language: Английский

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Navigating through the complexities of synucleinopathies: Insights into pathogenesis, heterogeneity, and future perspectives

Neuron, Journal Year: 2024, Volume and Issue: unknown

Published: June 1, 2024

Language: Английский

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Distinct Effects of Familial Parkinson’s Disease-Associated Mutations on α-Synuclein Phase Separation and Amyloid Aggregation

Biomolecules, Journal Year: 2023, Volume and Issue: 13(5), P. 726 - 726

Published: April 23, 2023

The Lewy bodies and neurites are key pathological hallmarks of Parkinson’s disease (PD). Single-point mutations associated with familial PD cause α-synuclein (α-Syn) aggregation, leading to the formation neurites. Recent studies suggest α-Syn nucleates through liquid–liquid phase separation (LLPS) form amyloid aggregates in a condensate pathway. How PD-associated affect LLPS its correlation aggregation remains incompletely understood. Here, we examined effects five identified PD, A30P, E46K, H50Q, A53T, A53E, on α-Syn. All other mutants behave similarly wild-type (WT) α-Syn, except that E46K mutation substantially promotes condensates. mutant droplets fuse WT recruit monomers into their droplets. Our showed A53T accelerated In contrast, A53E retarded during liquid-to-solid transition. Finally, observed formed condensates cells, whereas apparently promoted These findings reveal have divergent phase-separated condensates, providing new insights pathogenesis mutations.

Language: Английский

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