Huntingtin aggregation impairs autophagy leading to Argonaute-2 accumulation and global microRNA dysregulation
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA314448 | ENA |
REPOSITORIES: ENA
Dataset's files
| Action | DRS | |||
|---|---|---|---|---|
| SRR3206560.fastq.gz | Fastqsanger.gz | |||
| SRR3206570.fastq.gz | Fastqsanger.gz | |||
| SRR3206561.fastq.gz | Fastqsanger.gz | |||
| SRR3206571.fastq.gz | Fastqsanger.gz | |||
| SRR3206562.fastq.gz | Fastqsanger.gz |
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Project description:Many neurodegenerative diseases are characterized by the presence of intracellular protein aggregates resulting in alterations in autophagy. However, the consequences of impaired autophagy on neuronal function remain poorly understood. In this study, we used cell culture and mouse models of huntingtin protein aggregation, as well as post-mortem material from patients with Huntington's disease to demonstrate that Argonaute-2 (AGO2) accumulates in the presence of neuronal protein aggregates and that this is due to impaired autophagy. Accumulation of AGO2, a key factor of the RNAinduced silencing complex that executes microRNA functions, results in global alterations of microRNA levels and activity. Together these results demonstrate that impaired autophagy found in neurodegenerative diseases not only influences protein aggregation, but also directly contributes to global alterations of intracellular posttranscriptional networks.
2018-08-07 | GSE78928 | GEO
Project description:Synucleinopathies are triggered by the aggregation of α-synuclein (αSyn), leading to progressive neurodegeneration. However, the intracellular mechanism of αSyn aggregation remains unclear. Here we show that assembly of RNA G-quadruplexes (rG4s) form scaffolds for αSyn aggregation, contributing to neurodegeneration. Purified αSyn binds rG4s directly through the N-terminus. rG4 itself undergoes phase separation and assembly by Ca2+, accelerating the sol-gel phase transition of αSyn. In αSyn preformed fibrils (PFF)-treated neurons, rG4s assembly composed of synaptic mRNAs co-aggregates with αSyn upon Ca2+ excess influx into cytoplasm, eliciting synaptic dysfunction. Artificial assembly of rG4s using an optogenetic approach evokes αSyn aggregation and neuronal dysfunction. Administration of 5-aminolevulinic acid (5-ALA), a prodrug of protoporphyrin IX (PpIX) that prevents phase separation of rG4s, attenuating αSyn aggregation, neurodegeneration, and progressive motor deficits in PFF-injected synucleinopathy mice. Together, assembly of rG4s due to dysregulation of intracellular Ca2+ homeostasis accelerates αSyn phase transition and aggregation may contribute to pathogenesis of synucleinopathies.
2023-07-18 | GSE234238 | GEO
Project description:We report that the SUMO-targeted ubiquitin ligase (STUbL) Slx5 reduces the toxicity and abnormal transcriptional activity of a mutant, aggregation-prone fragment of huntingtin (htt), the causative agent of HD. An extra copy of SLX5 specifically reduces htt aggregates in the cytosol as well as chromatin-associated htt aggregates in the nucleus. Using RNA sequencing, we identified and confirmed specific targets of mHtt's transcriptional activity that are modulated by Slx5.
2018-06-20 | GSE115990 | GEO
Project description:Aggregation of α-synuclein scaffolds RNA G-quadruplexes assembly leading to progressive neurodegeneration
| PRJNA980607 | ENA
Project description:FUS/TLS is an RNA/DNA-binding protein associated with neurodegenerative diseases including amyotrophic lateral sclerosis and frontotemporal lobar degeneration. Previously, we found that a prion-like domain in the N-terminus of FUS/TLS mediates co-aggregation between FUS/TLS and mutant huntingtin, the gene product of Huntington's disease (HD). Here, we show that heterozygous knockout of FUS/TLS worsened the phenotypes of model mice of Huntington's disease (HD) but not spinal and bulbar muscular atrophy (SBMA). This difference was correlated with the degree of pathological association between disease proteins and FUS/TLS. Co-aggregation between FUS/TLS and mutant huntingtin resulted in the depletion of free FUS/TLS protein in HD mice that was detected as a monomer in SDS-PAGE analysis. Recently, we found that FUS/TLS paralogs, TAF15 and EWS, were up-regulated in homozygous FUS/TLS knockout mice. These two proteins were up-regulated in both HD and FUS/TLS heterozygote mice, and were further elevated in HD-TLS+/- double mutant mice, consistent with the functional impairment of FUS/TLS. These results suggest that FUS/TLS sequestration by co-aggregation is a rate-limiting factor of disease phenotypes of HD and that inclusions may have an adverse aspect, rather than being simply benign or protective. In addition, our results highlight inclusions as repositories of potential modifiers of neurodegeneration. Gene expression profiles were analyzed to examine the effects of FUS/TLS heterozygosity in mouse with or without the transgene of mutant huntingtin exon 1.
2017-02-12 | GSE80004 | GEO
Project description:Huntington's disease is a fatal neurodegenerative disorder characterized by the aggregation of polyglutamine-expanded huntingtin into oligomers and fibrils. How protein aggregation leads to cellular dysfunction is not well understood. To address this question, we combined in-cell single molecule fluorescence spectroscopy with quantitative proteomics to define how huntingtin engages in aberrant protein interactions during its progressive aggregation. We find that huntingtin interacts preferentially with key components of distinct cellular processes as aggregation proceeds from soluble oligomers to end-stage inclusions. The aberrant interactions of soluble oligomers are highly enriched on RNA-binding proteins and with proteins functioning in ribosome biogenesis, translation, transcription, and vesicle transport. A significant characteristic of these interactors is the presence of extended low-complexity sequence regions. Compared to the soluble aggregates, the interactome of insoluble inclusions is significantly less complex and is enriched in protein quality control components. Our results suggest a 'multiple hit' model for polyglutamine interactions in pathogenesis, with detrimental effects on cell function occurring in an aggregation stage-dependent manner.
2017-01-31 | PXD003446 | Pride
Project description:FUS/TLS is an RNA/DNA-binding protein associated with neurodegenerative diseases including amyotrophic lateral sclerosis and frontotemporal lobar degeneration. Previously, we found that a prion-like domain in the N-terminus of FUS/TLS mediates co-aggregation between FUS/TLS and mutant huntingtin, the gene product of Huntington's disease (HD). Here, we show that heterozygous knockout of FUS/TLS worsened the phenotypes of model mice of Huntington's disease (HD) but not spinal and bulbar muscular atrophy (SBMA). This difference was correlated with the degree of pathological association between disease proteins and FUS/TLS. Co-aggregation between FUS/TLS and mutant huntingtin resulted in the depletion of free FUS/TLS protein in HD mice that was detected as a monomer in SDS-PAGE analysis. Recently, we found that FUS/TLS paralogs, TAF15 and EWS, were up-regulated in homozygous FUS/TLS knockout mice. These two proteins were up-regulated in both HD and FUS/TLS heterozygote mice, and were further elevated in HD-TLS+/- double mutant mice, consistent with the functional impairment of FUS/TLS. These results suggest that FUS/TLS sequestration by co-aggregation is a rate-limiting factor of disease phenotypes of HD and that inclusions may have an adverse aspect, rather than being simply benign or protective. In addition, our results highlight inclusions as repositories of potential modifiers of neurodegeneration. Gene expression profiles were analyzed to examine the effects of FUS/TLS heterozygosity in mouse with or without the transgene of mutant androgen receptor.
2017-02-12 | GSE80093 | GEO
Project description:Aggregation of expanded polyglutamine repeat-containing fragments of the huntingtin (htt) protein may play a key role in Huntington's disease. Consistent with this hypothesis, two Ser-to-Asp mutations in the 17-amino-acid N-terminal htt(NT) segment abrogate both visible brain aggregates and disease symptoms in a full-length Q(97) htt mouse model while compromising aggregation kinetics and aggregate morphology in an htt fragment in vitro [Gu et al. (2009). Serines 13 and 16 are critical determinants of full-length human mutant huntingtin induced disease pathogenesis in HD mice. Neuron64, 828-840]. The htt(NT) segment has been shown to play a critical role in facilitating nucleation of amyloid formation in htt N-terminal exon1 fragments. We show here how these Ser-to-Asp mutations dramatically affect aggregation kinetics and aggregate structural integrity. First, these negatively charged Ser replacements impair the assembly of the ?-helical oligomers that play a critical role in htt amyloid nucleation, thus providing an explanation for reduced amyloid formation rates. Second, these sequence modifications alter aggregate morphology, decrease aggregate stability, and enhance the steric accessibility of the htt(NT) segment within the aggregates. Together, these changes make the sequence-modified peptides kinetically and thermodynamically less likely to aggregate and more susceptible, if they do, to posttranslational modifications and degradation. These effects also show how phosphorylation of a protein might achieve cellular effects via direct impacts on the protein's aggregation properties. In fact, preliminary studies on exon1-like molecules containing phosphoryl-Ser residues at positions 13 and 16 show that they reduce aggregation rates and generate atypical aggregate morphologies similar to the effects of the Ser-to-Asp mutants.
| S-EPMC3488119 | biostudies-literature
Project description:Within oomycetes, Phytophthora is a genus of eukaryotic microorganisms encompassing some of the most damaging plant pathogens. It spreads by airborne sporangia or waterborne zoospores. Zoospores perceive plant signals through chemotaxis and electrotaxis, and produce signals to attract other zoospores (autotaxis), resulting in auto-aggregation or biofilm formation on the plant surface. The mechanisms underlying intercellular communication and consequent attraction, adhesion and aggregation are largely unknown. Recent studies demonstrated that in Phytophthora parasitica the perception of K+ gradient induced coordinated motion and rapid aggregation. Based on this model, we combined data mining and ultrastructural microscopy analyses to propose a first definition of molecular events leading to oomycete aggregation. Results indicate that the transcriptome repertoire required for aggregation is fully functional already at this single zoospore stage, before aggregation or encystment. Freely swimming zoospores secrete or harbor proteins implied in aggregation through adhesion and extracellular matrix elaboration. They secrete vesicular and fibrillary material, including fibronectin-like proteins, resulting in intercellular structure formation. Consistently, the signature of transcriptome dynamics during transition from single-cell to aggregate is an upregulation of genes contributing to vesicular trafficking, possibly involved in adhesive proteins and extracellular matrix components mobilization. Moreover, the transcriptome signature suggests that pH homeostasis may contribute to aggregation by acting on both zoospore movement and adhesion.
2020-08-12 | GSE142435 | GEO
Project description:Huntingtin protein, mutated in Huntington disease, is implicated in nucleic acid- mediated processes, yet evidence for direct huntingtin-nucleic acid interaction is limited. Here we show wildtype and mutant huntingtin co-purify with nucleic acids, primarily RNA, and interact directly with G-rich RNAs in in vitro assays. Huntingtin RNA immunoprecipitation sequencing from patient-derived fibroblasts and neuronal progenitor cells expressing wildtype and mutant huntingtin revealed NEAT1 as a significantly enriched transcript. Altered NEAT1 levels were evident in Huntington’s disease cells and postmortem brain tissues, and huntingtin knockdown decreased NEAT1 levels. Huntingtin co-localized with NEAT1 in paraspeckles, and we identified a high-affinity RNA motif preferred by huntingtin. This study highlights NEAT1 as a novel huntingtin interactor, demonstrating huntingtin’s involvement in RNA-mediated functions and paraspeckle regulation.
2024-12-31 | GSE267435 | GEO