Ontology highlight
ABSTRACT:
PROVIDER: PRJNA730032 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:We've demonstrated that plants are resistant to the overexpression of polyglutamine (polyQ) extended proteins that cause protein aggregation and Huntington's disease in human cells. To investigate which proteins, maintain polyQ proteins correctly folded and avoid polyQ aggregates in plant cells. Our goal is to identify therapeutic candidate proteins that can potentially be used to treat Huntington's disease in human cell models.
2023-07-17 | PXD041001 | Pride
Project description:Problems arising during translation of mRNAs lead to ribosome stalling and collisions with trailing ribosomes. These collisions are known to trigger a series of events including degradation of the stalled nascent polypeptide, decay of the problematic mRNAs, and ribosome rescue. However, the systemic cellular response of ribosome collision has not been explored. Here, we uncover a novel function for ribosome collisions in signal transduction. Using multiple translation elongation inhibitors and cellular stress conditions, we show that ribosome collisions activate both the SAPK (Stress Activated Protein Kinase) and GCN2-mediated cellular stress response pathways that lead to apoptosis and the integrated stress response (ISR), respectively. We further show that the MAPKKK ZAK functions as the sentinel for ribosome collisions, and ZAK is required for activation of both SAPKs p38/JNK and GCN2 signaling pathways. Selective ribosome profiling and biochemistry demonstrate that ZAK preferentially associates with the minimal unit of colliding ribosomes, the disome, inducing ZAK phosphorylation. While ZAK associates with elongating ribosomes under non-stressed conditions, activation of ZAK is specifically trigger by colliding ribosomes. Together, these results provide new insights into how perturbation of translational homeostasis, as read-out by colliding ribosomes, regulates cell fate.
2020-08-18 | GSE141459 | GEO
Project description:Huntington’s disease (HD) is a neurodegenerative disorder caused by expansion of a CAG trinucleotide repeat in the Huntingtin (HTT) gene, encoding a homopolymeric polyglutamine (polyQ) tract. Although mutant HTT (mHTT) protein is known to aggregate, the links between aggregation and neurotoxicity remain unclear. Here we show that both translation and aggregation of wild-type and mHTT are regulated by a stress-responsive upstream open reading frame, and that polyQ expansions cause abortive translation termination and release of truncated, aggregation-prone mHTT fragments. Notably, we find that mHTT depletes translation elongation factor eIF5A in brains of symptomatic HD mice and cultured HD cells, leading to pervasive ribosome pausing and collisions. Loss of eIF5A disrupts homeostatic controls and impairs recovery from acute stress. Importantly, drugs that inhibit translation initiation reduce premature termination and mitigate this escalating cascade of ribotoxic stress and dysfunction in HD.
2024-03-13 | PXD026012 | Pride
Project description:Huntington's disease is caused by an expanded CAG repeat in the huntingtin gene, yeilding a Huntingtin protein with an expanded polyglutamine tract. Patient-derived induced pluripotent stem cells (iPSCs) can help understand disease; however, defining pathological biomarkers in challanging. Here we used LC-MS/MS to determine differences in mitochondrial proteome between iPSC-derived neurons from healthy donors and Huntington's disease patients.
2023-02-10 | PXD037526 | Pride
Project description:In Huntington's disease (HD), polyglutamine expansions in the huntingtin (Htt) protein cause subtle changes in cellular functions that, over-time, lead to neurodegeneration and death. Studies have indicated that activation of the heat shock response can reduce many of the effects of mutant Htt in disease models, suggesting that the heat shock response is impaired in the disease. To understand the basis for this impairment, we have used genome-wide chromatin immunoprecipitation followed by massively parallel sequencing (ChIP-Seq) to examine the effects of mutant Htt on the master regulator of the heat shock response, HSF1. We find that, under normal conditions, HSF1 function is highly similar in cells carrying either wild-type or mutant Htt. However, polyQ-expanded Htt severely blunts the HSF1-mediated stress response. Surprisingly, we find that the HSF1 targets most affected upon stress are not directly associated with proteostasis, but with cytoskeletal binding, focal adhesion and GTPase activity. Our data raise the intriguing hypothesis that the accumulated damage from life-long impairment in these stress responses may contribute significantly to the etiology of Huntington's disease. Affymetrix MG430 2.0 expression levels of wild-type (STHdhQ7/Q7) and mutant (STHdhQ111/Q111) striatal cells under growth condition (33 C) and upon heat shock (42 C for six hours)
2012-06-18 | E-GEOD-38001 | biostudies-arrayexpress
Project description:Ribosome rescue pathways recycle stalled ribosomes and target problematic mRNAs and aborted proteins for degradation. In bacteria, it remains unclear how rescue pathways distinguish ribosomes stalled in the middle of a transcript from actively translating ribosomes. In a genetic screen in E. coli, we discovered a novel rescue factor that has endonuclease activity. SmrB cleaves mRNAs upstream of stalled ribosomes, allowing the ribosome rescue factor tmRNA (which acts on truncated mRNA) to rescue upstream ribosomes. SmrB is recruited by ribosome collisions. Cryo-EM structures of collided disomes from E. coli and B. subtilis reveal interactions between the 30S subunits and a possible SmrB binding site. These findings show that ribosome collisions trigger ribosome rescue in bacteria and reveal the mechanism by which this occurs.
2022-08-01 | GSE179691 | GEO
Project description:Huntington's disease (HD) is a dominantly inherited genetic disease caused by mutant huntingtin (htt) protein with expanded polyglutamine tracts. A neuropathological hallmark of HD is the presence of neuronal inclusions of mutant htt. p62 is an important regulatory protein in selective autophagy, a process by which aggregated proteins are degraded, and it is associated with several neurodegenerative disorders including HD. Here we investigated the effect of p62 depletion in three HD model mice: R6/2, HD190QG and HD120QG mice. We found that loss of p62 in these models led to longer lifespans and reduced nuclear inclusions, although cytoplasmic inclusions increased with polyglutamine length. In mouse embryonic fibroblasts (MEFs) with or without p62, mutant htt with a nuclear localization signal (NLS) showed no difference in nuclear inclusion between the two MEF types. In the case of mutant htt without NLS, however, p62 depletion increased cytoplasmic inclusions. Furthermore, to examine the effect of impaired autophagy in HD model mice, we crossed R6/2 mice with Atg5 conditional knockout mice. These mice also showed decreased nuclear inclusions and increased cytoplasmic inclusions, similar to HD mice lacking p62. These data suggest that the genetic ablation of p62 in HD model mice enhances cytoplasmic inclusion formation by interrupting autophagic clearance of polyQ inclusions. This reduces polyQ nuclear influx and paradoxically ameliorates disease phenotypes by decreasing toxic nuclear inclusions. Gene expression profiles were analyzed to examine the effects of p62 depletion in mouse with or without mutant huntingtin exon 1 To examine the effect of p62 depletion on the transcriptome of Huntington's disease model mice, we crossed p62 knockout mice with HD model mice. We extracted total RNA from the striatum of these mice at 8 weeks and used for a microaaray analysis. The samples are HD transgenic mice with p62 knockout (HD_p62KO), HD mice with normal p62 (HD_p62WT), non-HD-transgenic mice with p62 knockout (NT_p62KO), and non-HD-transgenic mice with normal p62 (NT_p62WT).
2014-10-10 | E-GEOD-62210 | biostudies-arrayexpress
Project description:Cells can respond to stalled ribosomes by sensing ribosome collisions and employing quality control pathways. How ribosome stalling is resolved without collisions, however, has remained elusive. Here, focusing on non-colliding stalling exhibited by decoding-defective ribosomes, we identified Fap1 as a stalling sensor triggering 18S non-functional rRNA decay via poly-ubiquitination of uS3. Ribosome profiling revealed an enrichment of Fap1 at the translation initiation site but also association with elongating individual ribosomes. Cryo-EM structures of Fap1-bound ribosomes elucidated Fap1 probing the mRNA simultaneously at both the entry and exit channels suggesting a mRNA stasis sensing activity, and Fap1 sterically hinders formation of canonical collided di-ribosomes. Our findings indicate that individual stalled ribosomes are the potential signal for ribosome dysfunction, leading to accelerated turnover of the ribosome itself.
2022-09-15 | GSE159329 | GEO
Project description:Pluripotent stem cells undergo unlimited self-renewal while maintaining their potential to differentiate into post-mitotic cells with an intact proteome, a capacity that demands a highly induced proteostasis network. As such, induced pluripotent stem cells (iPSCs) suppress the aggregation of polyQ-expanded huntingtin (HTT), the mutant protein underlying Huntington’s disease (HD). Here we show that proteasome activity determines HTT levels, preventing the accumulation of polyQ-expanded aggregates in iPSCs from HD patients (HD-iPSCs). iPSCs exhibit intrinsic high levels of UBR5, an E3 ubiquitin ligase that we find required for proteasomal degradation of both normal and mutant HTT. When UBR5 fails to monitor HTT proteostasis, the concomitant up-regulation of HTT expression particularly results in polyQ-expanded aggregation in HD-iPSCs. Moreover, UBR5 knockdown hastens protein aggregation and neurotoxicity in polyQ-expanded invertebrate models. Notably, ectopic expression of UBR5 is sufficient to induce polyubiquitination and degradation of mutant HTT, reducing polyQ-expanded aggregates in HD cell models. However, UBR5 is dispensable for the proteostasis of other aggregation-prone proteins linked with Machado-Joseph disease or amyotrophic lateral sclerosis in iPSCs. Besides its role in HTT regulation, we find that intrinsic high levels of UBR5 also determine the global proteostatic ability of iPSCs preventing aggresome formation, suggesting a role in the control of misfolded proteins ensued from normal metabolism. Thus, our findings indicate UBR5 as a central component of super-vigilant proteostasis of iPSCs with the potential to correct proteostatic deficiencies in HD.
2018-06-14 | PXD009803 | Pride
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