Cross-Effects in Folding and Phase Transitions of hnRNP A1 and C9Orf72 RNA G4 In Vitro

Molecules, Год журнала: 2024, Номер 29(18), С. 4369 - 4369

Опубликована: Сен. 14, 2024

Abnormal intracellular phase transitions in mutant hnRNP A1 may underlie the development of several neurodegenerative diseases. The risk these diseases increases upon C9Orf72 repeat expansion and accumulation corresponding G-quadruplex (G4)-forming RNA, but link between this RNA disruption homeostasis has not been fully explored so far. Our aim was to clarify mutual effects G4 vitro. Using various optical methods atomic force microscopy, we investigated influence on formation cross-beta fibrils by prion-like domain (PLD) co-separation non-mutant protein with a typical SR-rich fragment splicing factor (SRSF), which normally drives assembly nuclear speckles. shown act holdase-like manner, i.e., restrict fibrillation PLD, presumably through interactions PLD-flanking RGG motif. These resulted partial unwinding G4, suggesting helicase-like activity RGG. At same time, disrupt SRSF, its possible contribution pathology interference regulation.

Язык: Английский

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Coalescence-Driven Local Crowding Promotes Liquid-to-Solid-Like Phase Transition in a Homogeneous and Heterogeneous Droplet Assembly

bioRxiv (Cold Spring Harbor Laboratory), Год журнала: 2024, Номер unknown

Опубликована: Окт. 9, 2024

Abstract Liquid-to-solid-like phase transition (LSPT) of disordered proteins via metastable liquid-like droplets is a well-documented phenomenon in biology and linked to many pathological conditions including neurodegenerative diseases. However, very less known about the early microscopic events transient intermediates involved irreversible protein aggregation functional globular proteins. Herein, using range spectroscopic techniques, we show that LSPT protein, human serum albumin (HSA) exclusively driven by spontaneous coalescence involving various temporal manner. We inter-droplet communication essential for both nucleation growth amorphous aggregates within individual droplets, which subsequently transform amyloid-like fibrils. Immobilized neither any nor upon aging. Moreover, found exchange materials with dilute dispersed has negligible influence on HSA. Notably, binding small ligands modulates feasibility kinetics HSA, suggesting possible regulatory mechanism cells utilize control dynamics LSPT. Further, dynamic heterogeneous droplet assembly two proteins, HSA transferrin (Tf), an intriguing fused where solid-like phases co-exist same droplet, eventually mixed fibrillar assembly. These insights not only highlight importance interactions behind biomolecules but also showcase its adverse effect structure function other crowded

Язык: Английский

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Polyphosphate Discriminates Protein Conformational Ensembles More Efficiently than DNA Promoting Diverse Assembly and Maturation Behaviors

bioRxiv (Cold Spring Harbor Laboratory), Год журнала: 2024, Номер unknown

Опубликована: Окт. 24, 2024

ABSTRACT Disordered proteins and domains often assemble into condensates with polyanionic nucleic acids, primarily via charge complementarity, regulating numerous cellular functions. However, the assembly mechanisms associated other abundant ubiquitous, anionic, stress-response polymer, polyphosphate (polyP), is less understood. Here, we employ intrinsically disordered DNA binding domain (DBD) of cytidine repressor (CytR) from E.coli to study nature processes their maturation polyP DNA. Wild-type CytR forms metastable liquid-like DNA, while undergoing liquid-to-solid transition in former solubilizing latter. On mutationally engineering ensemble exhibit more or structure dimensions than WT, process directed either partial time-dependent solubilization spontaneous aggregation, respectively. The timescales structural changes formed by folded mutant span tens minutes, indicative slow dynamics highlights tussle between folding driven intra-molecular interactions mediated inter-molecular interactions. hand, variants form only but droplets which solubilize within a few hours. Polyphosphate induces large secondary-structure two mutants adopting polyproline II-like structures droplets, has minimal effects. Our findings reveal how able efficiently discern conformational heterogeneity starting protein ensemble, its structure, compactness, broad implications involving stress response bacterial systems.

Язык: Английский

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Insight into the Thermo-responsive Phase Behavior of P1 Domain ofα-synuclein using Atomistic Simulations

bioRxiv (Cold Spring Harbor Laboratory), Год журнала: 2024, Номер unknown

Опубликована: Дек. 17, 2024

Abstract Biomolecular condensate formation driven by intrinsically disordered proteins (IDPs) is regulated interaction between various domains of the protein. Such condensates are implicated in neurodegenerative diseases. The presynaptic protein, α -Syn involved pathogenesis Parkinson’s disease. central non-amyloid β -component (NAC) domain protein considered to be a major driver pathogenic aggregation, although recent studies have suggested that P1 from flanking N-terminal region, can act as ‘master controller’ for function and aggregation. To gain molecular insight into phase behavior itself, we investigate how assemblies (residues 36-42) chains separate with varying temperatures using all-atom dynamics simulations. simulations reveal able above lower critical solution temperature. Formation condensed exclusion water molecules hydrophobic chains. chain density determined weak multi-chain interactions residues. Moreover, Tyrosine (Y 39 ) strongest contacts residue pairs dense phase. These results provide detailed picture key segment molecule, which may help deciphering full-length

Язык: Английский

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Application and progress of functionalized magnetic bead-based biosensors for protein detection

Progress in Medical Devices, Год журнала: 2024, Номер unknown

Опубликована: Дек. 31, 2024

In the field of bioanalysis, integration magnetic beads and biosensors provides a protein detection platform with high separation efficiency sensitivity. The superparamagnetism beads, combined surface functional modifications, forms basis for selectively capturing effectively separating target proteins. Additionally, sensitivity specificity ensure precise quantitative analysis captured This article systematically reviews synthesis strategies functionalized methods proteins nucleic acids, as well current technical challenges future development directions.

Язык: Английский

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