Similar Datasets
Project description:Chromatin binding of NRF1 after exposure to proteasome inhibitor
| PRJNA428954 | ENA
Project description:The maintenance of protein homeostasis is an essential characteristic of life. Transcription factor NRF1 (NFE2L1) has been reported to be activated by proteasome dysfunction, although the genome-wide target genes are poorly understood. Using ChIP-seq analysis, we found a potential association between NRF1 and autophagy. Our findings highlight the new activation mechanism of autophagy through gene regulation under proteasome dysfunction.
2023-03-19 | GSE227357 | GEO
Project description:The endoplasmic reticulum (ER) is a multifaceted organelle that plays an essential role in cellular processes such as protein folding, modification, and trafficking. It also acts as a proteostasis sensor and contributes to adaptation responses to maintain cellular homeostasis. The transcription factor NRF1 resides in the ER and is constantly transported from the ER to the cytosol for proteasomal degradation. However, when the proteasome function is defective, NRF1 escapes degradation and undergoes proteolytic cleavage by the protease DDI2, generating a transcriptionally active form that restores proteostasis, including proteasome function. Despite the importance of NRF1 in these processes, the mechanisms that regulate its proteolytic activation and transcriptional potential remain poorly understood. In this study, we utilized a functional molecular approach to elucidate the critical steps involved in NRF1 cleavage. Our results demonstrate that the ER is a crucial regulator of NRF1 function, orchestrating its ubiquitination by the ER-localized E3 ubiquitin ligase HRD1, a component of the ER-associated degradation (ERAD) pathway. Furthermore, we show that HRD1-mediated NRF1 ubiquitination is necessary for DDI2-mediated processing in cells. Notably, we found that the fusion of a ubiquitin moiety to NRF1 was sufficient to promote its proteolytic maturation by DDI2, thus bypassing the requirement for its trafficking to the ER. Our findings highlight the intricate mechanism by which NRF1 is activated by DDI2 and coordinates the transcriptional activity of an adaptation response in cells and suggest potential avenues for therapeutic interventions in conditions associated with proteasome impairment.
2023-09-05 | PXD041331 | Pride
Project description:The biological role and therapeutic potential of long non-coding RNAs (lncRNAs) in multiple myeloma (MM) are still to be investigated. Here, we studied the functional significance and the druggability of the oncogenic lncRNA MALAT1 in MM. Targeting MALAT1 by novel LNA-gapmeR anti-sense oligonucleotide antagonized MM cell proliferation and triggered apoptosis both in vitro and in vivo in a murine xenograft model of human MM. Of note, antagonism of MALAT1 dowmodulated the two major transcriptional activators of proteasome subunit genes, namely NRF1 and NRF2, and resulted in reduced trypsin, chymotrypsin and caspase-like proteasome activities and in accumulation of polyubiquitinated proteins. NRF1 and NRF2 decrease upon MALAT1-targeting was due to transcriptional activation of their negative regulator KEAP1, and resulted in reduced expression of anti-oxidant genes and increased ROS levels. In turn, NRF1 promoted MALAT1 expression thus establishing a positive feedback loop. Our findings demonstrate a crucial role of MALAT1 in the regulation of the proteasome machinery, and provide proof-of-concept that its targeting is a novel powerful option for the treatment of MM.
2018-12-31 | GSE108824 | GEO
Project description:Transcription factor NRF1 (NFE2L1) has been reported to be activated by proteasome disfunction, although the target genes are poorly understood. We used microarrays to identify NRF3-regulated gene expression network related to proteostasis.
2023-03-18 | GSE227232 | GEO
Project description:Eukaryotic transcription factors (TFs) are key determinants of gene activity, yet they bind only a fraction of their corresponding DNA sequence motifs in any given cell type. Chromatin has the potential to restrict accessibility of binding sites; however, in which context chromatin states are instructive for TF binding remains mainly unknown. To explore the contribution of DNA methylation to constrained TF binding, we mapped DNase-I-hypersensitive sites in murine stem cells in the presence and absence of DNA methylation. Methylation-restricted sites are enriched for TF motifs containing CpGs, especially for those of NRF1. In fact, the TF NRF1 occupies several thousand additional sites in the unmethylated genome, resulting in increased transcription. Restoring de novo methyltransferase activity initiates remethylation at these sites and outcompetes NRF1 binding. This suggests that binding of DNA-methylationsensitive TFs relies on additional determinants to induce local hypomethylation. In support of this model, removal of neighbouring motifs in cis or of a TF in trans causes local hypermethylation and subsequent loss of NRF1 binding. This competition between DNA methylation and TFs in vivo reveals a case of cooperativity between TFs that acts indirectly via DNA methylation. Methylation removal by methylation-insensitive factors enables occupancy of methylation-sensitive factors, a principle that rationalizes hypomethylation of regulatory regions. DNase-seq (2 replicates) in mouse embryonic stem cells with (WT) and without DNA methylation (DNMT TKO). RNA-seq (3 replicates) in WT and DNMT TKO cells and in DNMT TKO cells after treatment with control siRNA or siRNA targeting Nrf1. H3K27ac ChIP-seq (2 replicates) in WT and DNMT TKO cells. NRF1 ChIP-seq (2 replicates) in WT and DNMT TKO cells, in WT upon culture in different conditions (adaptation to 2i and back to serum), upon transient overexpression of NRF1 and after differentiation into neuronal progenitor cells (NP). Whole-genome bisulfite sequencing in DNMT TKO cells and in WT upon culture in different conditions (adaptation to 2i and back to serum). NRF1 ChIP-seq (2 replicates) in human HMEC and HCC1954 cells.
2015-12-16 | E-GEOD-67867 | biostudies-arrayexpress
Project description:DNA-damage inducible 1 homolog 2 (DDI2) is an aspartic protease that cleaves and activates the transcription factor NRF1. Cellular models have shown that this pathway contributes to cell-stress adaption, for example, upon proteasome inhibition. However, DDI2 physiological function is unknown. Ddi2 Knock-out (KO) mice are embryonic lethal. However, we found that liver-specific Ddi2-KO animals are viable. We used comprehensive genetic analysis to identify the molecular pathways regulated by DDI2. We show that DDI2 mediates metallothionein (MT) expression in mouse and human hepatocytes in response to cadmium (Cd). Cd exposure inhibits the proteasome activity, resulting in NRF1 accumulation in the cytoplasm, followed by cleavage by DDI2 and translocation to the nucleus to activate MTs. Depleting DDI2 or NRF1 by CRISPR/Cas9 impaired MTs activation and sensitized the cells to Cd or cisplatin toxicity. This study identifies a new function for DDI2 that links proteasome homeostasis to heavy metal mediated toxicity.
2022-10-19 | GSE198150 | GEO
Project description:In this study, we compared the transcriptional profile of NIH-3T3 cells that are either wild-type (WT) or Nrf1 knockout (Nrf1-KO). We treated these cells with carfilzomib for 6 hours or 24 hours and performed RNA-sequencing with these samples.
2020-05-21 | GSE144817 | GEO
Project description:Analysis of binding of the transcriptional factor Nrf1 in mouse embryonic stem cells by ChIP-Seq
2017-12-15 | E-MTAB-3475 | biostudies-arrayexpress
Project description:Heart disease can be caused by ischemic coronary artery injury, hypertension, and chemotherapy, all of which lead to loss or dysfunction of cardiac muscle. The adult mammalian heart lacks the ability to regenerate. In contrast, the heart of neonatal mice, within the first week after birth, possesses a unique ability to regenerate lost myocardium following injury, mediated by proliferation of cardiomyocytes. The mechanisms whereby neonatal cardiomyocytes adapt to injury-induced stress conditions and activate regenerative cellular programs remain to be defined. Here, we show that Nrf1, an endoplasmic reticulum (ER) bound transcription factor, is expressed in regenerating cardiomyocytes. Genetic deletion of Nrf1 prevented cardiomyocytes from activating a transcriptional program required for heart regeneration, revealed by single-nucleus RNA sequencing (snRNA-seq). Conversely, adeno-associated virial (AAV) overexpression of Nrf1 protected the adult mouse heart from ischemia/reperfusion (I/R) injury. Nrf1 also protected human induced pluripotent stem cell-derived cardiomyocytes (hPSC-CMs) from doxorubicin-induced cardiotoxicity. The protective function of Nrf1 is mediated by a dual stress response mechanism involving activation of the proteasome and redox balance. Our findings reveal a mechanistic interplay between adaptive stress responses and heart regeneration, and highlight the central role of Nrf1 in these processes.
2021-05-01 | GSE163630 | GEO