Featured
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| Open AccessAn HDAC6-dependent surveillance mechanism suppresses tau-mediated neurodegeneration and cognitive decline
HDAC6 is a tau deacetylase and acetylation of tau inhibits its function and promotes aggregation. Here the authors show that HDAC6 protects against tau accumulation in a mouse model of tauopathy.
- Hanna Trzeciakiewicz
- , Deepa Ajit
- & Todd J. Cohen
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Article
| Open AccessTurn-on chemiluminescence probes and dual-amplification of signal for detection of amyloid beta species in vivo
Detection of amyloid beta deposits is often performed with fluorescent compounds that bind plaques. Here the authors develop turn-on chemiluminescent probes that bind amyloid beta plaques in vivo, and amplify the signal via chemiluminescence resonance energy transfer to the plaque-binding fluorescent molecule CRANAD-3.
- Jing Yang
- , Wei Yin
- & Chongzhao Ran
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Article
| Open AccessRetromer stabilization results in neuroprotection in a model of Amyotrophic Lateral Sclerosis
ALS is a neurodegenerative disease characterized by loss of motor neurons. Here, the authors showed that reduced levels of the VSP35 subunit in the retromer complex is a conserved ALS feature and identified a new lead compound increasing retromer stability ameliorating the disease phenotype.
- Luca Muzio
- , Riccardo Sirtori
- & Gianvito Martino
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Article
| Open AccessNSs amyloid formation is associated with the virulence of Rift Valley fever virus in mice
Rift Valley fever virus (RVFV) can cause severe diseases in humans, including encephalitis. Here the authors show that NSs, the major virulence factor of RVFV, is an amyloidogenic protein forming fibrils in infected mouse brains and causing increased mortality in mice.
- Psylvia Léger
- , Eliana Nachman
- & Pierre-Yves Lozach
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Article
| Open AccessNonsense-mediated mRNA decay factor UPF1 promotes aggresome formation
Nonsense-mediated mRNA decay (NMD) is a translation-coupled process that eliminates mRNAs containing premature translation-termination codons. Here the authors identify a role for the NMD factor UPF1 in protein quality control, whereby truncated misfolded polypeptides are cleared through autophagy.
- Yeonkyoung Park
- , Joori Park
- & Yoon Ki Kim
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Article
| Open AccessA multi-omics analysis reveals the unfolded protein response regulon and stress-induced resistance to folate-based antimetabolites
The unfolded protein response (UPR) is a stress response pathway implicated in numerous diseases and chemotherapy resistance. Here, the authors define the UPR regulon with a multi-omics strategy, uncovering changes to mitochondrial one-carbon metabolism and concomitant resistance to folate-based therapeutics.
- Stefan Reich
- , Chi D. L. Nguyen
- & Jan Medenbach
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Article
| Open AccessLiquid-liquid phase separation induces pathogenic tau conformations in vitro
Tau plays an important role in tauopathies and undergoes liquid-liquid phase separation (LLPS). The authors show that disease-related P301L mutant and phosphomimic (S199E/S202E/T205E) tau enhance LLPS in vitro at physiological levels, and using specific antibodies, that tau LLPS leads to pathological conformations such as N-terminal exposure and oligomeric species.
- Nicholas M. Kanaan
- , Chelsey Hamel
- & Benjamin Combs
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Article
| Open AccessAn in vivo platform to select and evolve aggregation-resistant proteins
Protein aggregation remains a significant challenge for manufacturing of protein biopharmaceuticals. Here, the authors demonstrate the use of directed evolution and an assay for in vivo innate protein aggregation-propensity to generate aggregation-resistant scFv fragments.
- Jessica S. Ebo
- , Janet C. Saunders
- & David J. Brockwell
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Article
| Open AccessLiquid-liquid phase separation and extracellular multivalent interactions in the tale of galectin-3
Galectin-3 consists of an unstructured N-terminal domain (NTD) and a structured carbohydrate-recognition domain and agglutinates neutrophils and glycosylated molecules in the extracellular milieu. Here the authors combine biophysical and biochemical experiments with NMR measurements and show that the galectin-3 NTD undergoes liquid-liquid phase separation (LLPS) and agglutinates other molecules through this process.
- Yi-Ping Chiu
- , Yung-Chen Sun
- & Jie-rong Huang
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Article
| Open AccessCerebellum-enriched protein INPP5A contributes to selective neuropathology in mouse model of spinocerebellar ataxias type 17
It is not yet clear how ubiquitously-expressed proteins can cause the selective degeneration of particular populations of neurons, such as in spinocerebellar ataxia type 17, SCA17, which results from a CAG trinucleotide repeat expansion in the ubiquitously expressed transcription factor TBP. Here, the authors show that mutant TBP suppresses the cerebellum-enriched transcription of Inpp5a and link altered levels of INPP5A to the selective degeneration of cerebellar neurons.
- Qiong Liu
- , Shanshan Huang
- & Shihua Li
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Article
| Open AccessArginine π-stacking drives binding to fibrils of the Alzheimer protein Tau
Tau fibril formation is a hallmark of Alzheimer’s disease. Here the authors reveal an aggregation-dependent protein interaction pattern of Tau and further show that π-stacking of the arginine side-chains drives aberrant protein binding to Tau fibrils.
- Luca Ferrari
- , Riccardo Stucchi
- & Stefan G. D. Rüdiger
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Article
| Open AccessSingle-molecule detection on a portable 3D-printed microscope
Single-molecule in vitro assays require dedicated confocal microscopes equipped with fluorescence correlation spectroscopy (FCS) modules. Here the authors present a compact, cheap and open-source 3D-printed confocal microscope for single photon counting and FCS measurements, and use it to detect α-synuclein aggregation.
- James W. P. Brown
- , Arnaud Bauer
- & Yann Gambin
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Article
| Open AccessThe autophagy receptor p62/SQST-1 promotes proteostasis and longevity in C. elegans by inducing autophagy
While the cellular recycling process autophagy has been linked to aging, the impact of selective autophagy on lifespan remains unclear. Here Kumsta et al. show that the autophagy receptor p62/SQSTM1 is required for hormetic benefits and p62/SQSTM1 overexpression is sufficient to extend C. elegans lifespan and improve proteostasis.
- Caroline Kumsta
- , Jessica T. Chang
- & Malene Hansen
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Article
| Open AccessMolecular basis for chirality-regulated Aβ self-assembly and receptor recognition revealed by ion mobility-mass spectrometry
Chiral inversion of amino acids is thought to modulate the structure and function of amyloid beta (Aβ) but these processes are poorly understood. Here, the authors develop an ion mobility-mass spectrometry based approach to study chirality-regulated structural features of Aβ fragments and their influence on receptor recognition.
- Gongyu Li
- , Kellen DeLaney
- & Lingjun Li
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Article
| Open AccessTau deposition is associated with functional isolation of the hippocampus in aging
Deposition of tau protein aggregates occurs during aging and Alzheimer disease. Here, the authors show that tau burden in the anterior-temporal memory network is associated with disrupted fMRI connectivity and functional isolation of the hippocampus from other memory network components.
- Theresa M. Harrison
- , Anne Maass
- & William J. Jagust
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Article
| Open AccessCellular sequestrases maintain basal Hsp70 capacity ensuring balanced proteostasis
The sequestration of misfolded proteins into large assemblies by sequestrases is now considered as the third pillar in protein quality control besides chaperones and proteases. Here the authors characterise the functions of the sequestrases Hsp42 and Btn2 in the proteostasis network of S. cerevisiae and find that they protect cells from too exhaustive depletion of the Hsp70 system.
- Chi-ting Ho
- , Tomas Grousl
- & Axel Mogk
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Article
| Open AccessAtomic-level insight into mRNA processing bodies by combining solid and solution-state NMR spectroscopy
Processing bodies are membrane less organelles that contain enzymes involved in mRNA turnover, among them enhancer of decapping 3 (Edc3). Here the authors use solid- and solution-state NMR spectroscopy to characterize the structural organization and dynamics of Edc3 and find that its interactions with RNA and between the different Edc3 domains are largely preserved in the phase-separated state.
- Reinier Damman
- , Stefan Schütz
- & Marc Baldus
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Article
| Open AccessConstitutive XBP-1s-mediated activation of the endoplasmic reticulum unfolded protein response protects against pathological tau
Accumulation of abnormal tau protein drives neurodegeneration in Alzheimer’s disease and related dementia disorders. Here, the authors demonstrate the endoplasmic reticulum unfolded protein response mediator XBP-1 controls pathological tau accumulation and the resultant neurodegeneration in a transgenic C. elegans model.
- Sarah M. Waldherr
- , Timothy J. Strovas
- & Brian C. Kraemer
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Article
| Open AccessAtomic structure of PI3-kinase SH3 amyloid fibrils by cryo-electron microscopy
The Src-homology 3 domain of phosphatidyl-inositol-3-kinase (PI3K-SH3) is a model system for studying amyloid fibril formation. Here the authors present the 3.4 Å cryo-EM structure of the PI3K-SH3 amyloid fibril, which allows them to rationalize the effects of mutations on the kinetics of fibril formation.
- Christine Röder
- , Nicola Vettore
- & Gunnar F. Schröder
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Article
| Open AccessThe prion-like protein kinase Sky1 is required for efficient stress granule disassembly
The factors regulating stress granule dissolution are not fully understood. Here, the authors identify Sky1 as a stress granule component in yeast, and show that Sky1 kinase activity is required for timely stress granule disassembly during stress recovery.
- Jenifer E. Shattuck
- , Kacy R. Paul
- & Eric D. Ross
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Article
| Open AccessArtificial coiled coil biomineralisation protein for the synthesis of magnetic nanoparticles
Proteins have been used in the synthesis of magnetic nanoparticles but issues with aggregation limit this application. Here, the authors report on the synthesis of coiled proteins that display the active loop of the natural proteins to avoid aggregation and investigate the application in nanoparticle synthesis.
- Andrea E. Rawlings
- , Lori A. Somner
- & Sarah S. Staniland
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Article
| Open AccessStructural basis for substrate gripping and translocation by the ClpB AAA+ disaggregase
Bacterial ClpB is a disaggregase that solubilizes protein aggregates. Here the authors present the 2.9 Å cryo-EM structure of a hyperactive variant of ClpB bound to the substrate casein in active translocation states and discuss its polypeptide translocation mechanism.
- Alexandrea N. Rizo
- , JiaBei Lin
- & Daniel R. Southworth
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Article
| Open AccessStructural basis for reversible amyloids of hnRNPA1 elucidates their role in stress granule assembly
Low complexity (LC) domains can drive the formation of both amyloid fibrils and protein droplets. Here, the authors identify reversible amyloid cores from the LC of hnRNPA1, based on which they elucidate the structural basis of reversible fibrillation and its interplay with hnRNPA1 droplet formation.
- Xinrui Gui
- , Feng Luo
- & Dan Li
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Article
| Open AccessCo-translational assembly of mammalian nuclear multisubunit complexes
Genes encoding protein complex subunits are often dispersed in the genome of eukaryotes, raising the question how these protein complexes assemble. Here, the authors provide evidence that mammalian nuclear transcription complexes are formed co-translationally to ensure specific and functional interactions.
- Ivanka Kamenova
- , Pooja Mukherjee
- & László Tora
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Article
| Open AccessDifferent soluble aggregates of Aβ42 can give rise to cellular toxicity through different mechanisms
Amyloid beta (Aβ42) peptides form heterogeneous mixtures of aggregates, which are closely linked to Alzheimer’s disease. This study shows how different types of Aβ42 aggregates are associated with distinct mechanisms of toxicity
- Suman De
- , David C. Wirthensohn
- & David Klenerman
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| Open AccessCryo-EM structure of a light chain-derived amyloid fibril from a patient with systemic AL amyloidosis
Systemic AL amyloidosis is caused by misfolding of immunoglobulin light chains and is one of the most frequently occurring forms of systemic amyloidosis. Here the authors present the 3.3 Å cryo-EM structure of a λ1 AL amyloid fibril that was isolated from an explanted human heart.
- Lynn Radamaker
- , Yin-Hsi Lin
- & Marcus Fändrich
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Article
| Open AccessProteome-wide solubility and thermal stability profiling reveals distinct regulatory roles for ATP
ATP can function as a biological hydrotrope, but its global effects on protein solubility have not yet been characterized. Here, the authors quantify the effect of ATP on the thermal stability and solubility of the cellular proteome, providing insights into protein solubility regulation by ATP.
- Sindhuja Sridharan
- , Nils Kurzawa
- & Mikhail M. Savitski
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Article
| Open AccessCryo-EM fibril structures from systemic AA amyloidosis reveal the species complementarity of pathological amyloids
Systemic AA amyloidosis is caused by misfolding of the acute phase protein serum amyloid A1. Here the authors present the cryo-EM structures of murine and human AA amyloid fibrils that were isolated from tissue samples and describe how the fibrils differ in their fundamental structural properties.
- Falk Liberta
- , Sarah Loerch
- & Matthias Schmidt
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Article
| Open AccessA viral expression factor behaves as a prion
Prion-forming proteins have been found in animals, plants, fungi, and bacteria. Here, Nan et al. report that a baculovirus-encoded protein behaves as prion in a yeast system and forms aggregates at high multiplicity of infection in insect cells that affect baculovirus replication.
- Hao Nan
- , Hongying Chen
- & Xiaodong Xu
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Article
| Open AccessFibril formation and therapeutic targeting of amyloid-like structures in a yeast model of adenine accumulation
Small molecule metabolites like phenylalanine can form amyloid-like structures but so far this has only been demonstrated in vitro. Here the authors generate a yeast in vivo model of adenine self-assembly and characterize the adenine assemblies in cells by indicative amyloid dye and anti-adenine assemblies antibodies.
- Dana Laor
- , Dorin Sade
- & Ehud Gazit
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Article
| Open AccessCompeting protein-protein interactions regulate binding of Hsp27 to its client protein tau
Small heat shock proteins (sHSPs) limit the aggregation of proteins, such as tau. Here the authors show that Hsp27 recognizes two aggregation-prone regions of tau and that this interaction competes with Hsp27 oligomerization.
- Rebecca Freilich
- , Miguel Betegon
- & Jason E. Gestwicki
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Article
| Open AccessThe structure of a β2-microglobulin fibril suggests a molecular basis for its amyloid polymorphism
Impaired kidney function can lead to an increase of β2-microglobulin (β2m) serum levels, which can cause β2m aggregation and amyloid fibril formation. Here the authors combine cryo-EM and magic angle spinning NMR measurements to determine the structure of a β2m fibril and they also present the low resolution model of a β2m fibril with a different morphology.
- Matthew G. Iadanza
- , Robert Silvers
- & Sheena E. Radford
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Article
| Open AccessMicrofluidic deposition for resolving single-molecule protein architecture and heterogeneity
Manual sample deposition on a substrate can introduce artifacts in quantitative AFM measurements. Here the authors present a microfluidic spray device for reliable deposition of subpicoliter droplets which dry out in milliseconds after landing on the surface, thereby avoiding protein self-assembly.
- Francesco Simone Ruggeri
- , Jerome Charmet
- & Tuomas P. J. Knowles
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Article
| Open AccessCryo-EM of full-length α-synuclein reveals fibril polymorphs with a common structural kernel
The intrinsically disordered protein alpha-synuclein (aSyn) forms polymorphic fibrils. Here the authors provide molecular insights into aSyn fibril polymorphism and present the cryo-EM structures of the two predominant species, a rod and a twister both determined at 3.7 Å resolution.
- Binsen Li
- , Peng Ge
- & Lin Jiang
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| Open AccessExtreme amyloid polymorphism in Staphylococcus aureus virulent PSMα peptides
The phenol-soluble modulin PSMα3 secreted by Staphylococcus aureus forms cross-α amyloid-like fibrils. Here the authors reveal the amyloid polymorphism of PSMs by presenting the cross-β amyloid fibril structures of the biofilm-associated PSMα1 and PSMα4 and showing that truncated PSMα3 antibacterial peptides form distinct out-of-register β-sheets and a polymorph with a hexameric architecture of β-sheets.
- Nir Salinas
- , Jacques-Philippe Colletier
- & Meytal Landau
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Article
| Open AccessLRRK2 kinase regulates α-synuclein propagation via RAB35 phosphorylation
Mutations in LRRK2 kinase are associated with Parkinson’s disease. Here the authors show that LRRK2 modulates propagation of α-synuclein, using rodent and C. elegans models, and show that this is dependent on phosphorylation of one of its substrates, RAB35.
- Eun-Jin Bae
- , Dong-Kyu Kim
- & Seung-Jae Lee
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Article
| Open AccessFemtosecond X-ray coherent diffraction of aligned amyloid fibrils on low background graphene
The structures of amyloid fibres are currently primarily studied through solid state NMR and cryo-EM. Here the authors present a free-standing graphene support device that allows diffraction imaging of non-crystalline amyloid fibrils with single X-ray pulses from an X-ray free-electron laser.
- Carolin Seuring
- , Kartik Ayyer
- & Henry N. Chapman
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Article
| Open AccessConformational dynamics in crystals reveal the molecular bases for D76N beta-2 microglobulin aggregation propensity
The aggregation prone D76N beta-2 microglobulin mutant causes systemic amyloidosis. Here the authors combine crystallography, solid-state NMR, and computational studies and show that the D76N mutation increases protein dynamics and destabilizes the outer strands, which leads to an exposure of amyloidogenic parts explaining its aggregation propensity.
- Tanguy Le Marchand
- , Matteo de Rosa
- & Stefano Ricagno
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Article
| Open AccessConformational switching within dynamic oligomers underpins toxic gain-of-function by diabetes-associated amyloid
Toxic gain-of-function by islet amyloid polypeptide (IAPP) is thought to be mediated by membrane poration. Here the authors develop diluted-FRET to show that changes in pore structure correlate with onset of toxicity inside insulin secreting cells.
- Melissa Birol
- , Sunil Kumar
- & Andrew D. Miranker
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Article
| Open AccessA common mechanism of proteasome impairment by neurodegenerative disease-associated oligomers
Disruption of the ubiquitin proteasome system (UPS) is often associated with neurodegenerative diseases. Here the authors demonstrate the existence of a general mechanism of proteasomal impairment triggered by a specific protein oligomer structure, irrespective of its protein constituent.
- Tiffany A. Thibaudeau
- , Raymond T. Anderson
- & David M. Smith
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Article
| Open AccessAggregating sequences that occur in many proteins constitute weak spots of bacterial proteostasis
Aggregation is sequence-specific and nucleated by short aggregating protein segments (APR). Here authors use a multidisciplinary approach to show that in E.coli some frequently occurring APRs lead to protein aggregation and ultimately bacterial cell death, which could serve as antibacterial strategy.
- Ladan Khodaparast
- , Laleh Khodaparast
- & Joost Schymkowitz
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Article
| Open AccessPhysical basis of amyloid fibril polymorphism
Amyloid fibril structures can display polymorphism. Here the authors reveal the cryo-EM structures of several different fibril morphologies of a peptide derived from an amyloidogenic immunoglobulin light chain and present a mathematical analysis of physical factors that influence fibril polymorphism.
- William Close
- , Matthias Neumann
- & Marcus Fändrich
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Article
| Open AccessDiscovery and characterization of stable and toxic Tau/phospholipid oligomeric complexes
The Alzheimer protein Tau interacts with biological membranes, but the role of these interactions in regulating Tau function in health and disease remains unexplored. Here, the authors report on the discovery and characterization of neurotoxic oligomeric protein/phospholipid complexes.
- Nadine Ait-Bouziad
- , Guohua Lv
- & Hilal A. Lashuel
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Article
| Open AccessCompetition between crystal and fibril formation in molecular mutations of amyloidogenic peptides
Aggregation of amyloidogenic peptides into fibrils and crystals has incidence in several amyloid-related diseases. Here, the authors investigate the origins of the fibril-to-crystal conversion in amyloidogenic hexapeptides pointing to the amyloid crystals as the ground state in the protein folding energy landscape.
- Nicholas P. Reynolds
- , Jozef Adamcik
- & Raffaele Mezzenga
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Article
| Open AccessSpecies-dependent structural polymorphism of Y145Stop prion protein amyloid revealed by solid-state NMR spectroscopy
Prion diseases can be transmitted across species. Here the authors use solid-state NMR to study prion protein (PrP) amyloids from human, mouse and Syrian hamster and show that their structural differences are mainly governed by two residues, which helps to understand interspecies PrP propagation on a molecular level.
- Theint Theint
- , Philippe S. Nadaud
- & Christopher P. Jaroniec
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Article
| Open AccessSeed-induced acceleration of amyloid-β mediated neurotoxicity in vivo
Seeding of amyloid beta from one brain region to another is thought to contribute to the progression of Alzheimer’s disease, although to date most studies have depended on inoculation of animals with exogenous amyloid. Here the authors describe a genetic seed and target system in Drosophila which may be useful for the mechanistic study of seeding of amyloid in vivo.
- Ramona F. Sowade
- & Thomas R. Jahn
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Article
| Open AccessA thiol probe for measuring unfolded protein load and proteostasis in cells
Proteostasis is maintained through a number of molecular mechanisms, some of which function to protect the folded state of proteins. Here the authors demonstrate the use of TPE-MI in a fluorigenic dye assay for the quantitation of unfolded proteins that can be used to assess proteostasis on a cellular or proteome scale.
- Moore Z. Chen
- , Nagaraj S. Moily
- & Danny M. Hatters
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Article
| Open AccessAcetylation-induced TDP-43 pathology is suppressed by an HSF1-dependent chaperone program
TDP-43 aggregation is linked to various diseases including amyotrophic lateral sclerosis. Here the authors show that acetylation of the protein triggers TDP-43 pathology in cultured cells and mouse skeletal muscle, which can be cleared through an HSF1-dependent chaperone mechanism that disaggregates the protein.
- Ping Wang
- , Connor M. Wander
- & Todd J. Cohen
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Article
| Open AccessMisfolded polypeptides are selectively recognized and transported toward aggresomes by a CED complex
Misfolded polypeptide aggregates are actively transported to aggresomes, where they are degraded through aggrephagy. Here the authors show that these aggregates are selectively recognized by the CTIF–eEF1A1–DCTN1 (CED) complex and transported to aggresomes through the interactions of DCTN1 with dynein motors.
- Joori Park
- , Yeonkyoung Park
- & Yoon Ki Kim