Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

In beta-actin knockout mouse embryonic fibroblasts epigenetic reprogramming and chromatin modifications lead to rDNA transcription inactivation and defects in cell growth and proliferation

ABSTRACT: Actin and nuclear myosin 1 (NM1) are emerging as regulators of transcription and chromatin organization. Using a genome-wide approach we report here that β-actin binds both intergenic and genic regions across the entire mammalian genome, associated with both protein-coding and rRNA genes. Across the rDNA transcription unit the distribution of β-actin correlated with NM1 and the other subunits of the B-WICH complex, WSTF and SNF2h. In β-actin-/- mouse embryonic fibroblasts (MEFs), we found that rRNA synthesis levels are down-regulated concomitantly with drops in Pol I and NM1 occupancies across the rRNA gene. In knock-in experiments, reintroduction of wild-type β-actin but not mutated forms with polymerization defects, rescued rRNA synthesis underscoring the direct role for β-actin in Pol I transcription and the importance of polymerization during the transcription process. The rRNA defects in the β-actin-/-MEFs are accompanied by epigenetic reprogramming that leads to up-regulation of the repressive mark H3K4me1. In addition, a high resolution chromatin accessibility assay showed that the absence of β-actin leads to a more compact chromatin at specific locations, including promoter-proximal enhancer (T0 sequence) and Sal boxes (T1-T10), disturbing binding of the transcription termination factor 1 (TTF1). We propose a novel mechanism where the polymerase-associated β-actin synergizes with NM1 to coordinate the establishment of permissive chromatin with the correct rDNA topology for Pol I transcription enhancement.

ORGANISM(S): Mus musculus

PROVIDER: GSE68686 | GEO | 2015/10/04

SECONDARY ACCESSION(S): PRJNA283394

REPOSITORIES: GEO

ACCESS DATA

Json Xml

Dataset's files

Source:

			Action	DRS
		Other

Items per page:

1 - 1 of 1

Similar Datasets

Glycogen synthase kinase (GSK) 3β phosphorylates and protects nuclear myosin 1c from proteasome-mediated degradation to activate rDNA transcription in early G1 cells

Project description:Nuclear myosin 1c (NM1) mediates RNA polymerase I (pol I) transcription activation and cell cycle progression by facilitating PCAF-mediated H3K9 acetylation, but the molecular mechanism by which NM1 is regulated remains unclear. Here, we report that at early G1 the glycogen synthase kinase (GSK) 3β phosphorylates and stabilizes NM1, allowing for NM1 association with the chromatin. Genomic analysis by ChIP-Seq showed that this mechanism occurs on the rDNA as active GSK3β selectively occupies the gene. ChIP assays and transmission electron microscopy in GSK3β-/- mouse embryonic fibroblasts indicated that at G1 rRNA synthesis is suppressed due to decreased H3K9 acetylation leading to a chromatin state incompatible with transcription. We found that GSK3β directly phosphorylates the endogenous NM1 on a single serine residue (Ser-1020) located within the NM1 C-terminus. In G1 this phosphorylation event stabilizes NM1 and prevents NM1 polyubiquitination by the E3 ligase UBR5 and proteasome-mediated degradation. We conclude that GSK3β-mediated phosphorylation of NM1 is required for pol I transcription activation. Examination of GSK3beta with the genome in mouse embryonic fibroblasts

2014-05-02 | E-GEOD-57153 | biostudies-arrayexpress

Glycogen synthase kinase (GSK) 3β phosphorylates and protects nuclear myosin 1c from proteasome-mediated degradation to activate rDNA transcription in early G1 cells

2014-05-02 | GSE57153 | GEO

Nuclear myosin 1 contributes to a chromatin landscape compatible with RNA polymerase II transcription activation

Project description:Nuclear myosin 1c (NM1) is emerging as regulator of transcription and chromatin organization. Using a genome-wide approach we report here that NM1 binds across the mammalian genome with occupancy peaks at class II gene promoters, correlating with distributions of RNA Polymerase II (Pol II) and active epigenetic marks. We show that NM1 synergizes with polymerase-associated actin to maintain active Pol II at gene promoters. NM1 also co-localizes with the nucleosome remodeler SNF2h at class II promoters where they assemble together with WSTF as part of the B-WICH complex to remodel chromatin. Following B-WICH assembly, NM1 mediates physical recruitment of the histone acetyl transferase PCAF and the histone methyl transferase Set1/Ash2 to maintain and preserve H3K9acetylation and H3K4trimethylation for active transcription. We propose a novel genome-wide mechanism where myosin synergizes with Pol II-associated actin to link the polymerase machinery with permissive chromatin for transcription activation. Association of nuclear myosin 1 (NM1) with the genome in mouse embryonic fibroblasts

2015-05-04 | E-GEOD-66542 | biostudies-arrayexpress

Nuclear myosin 1 contributes to a chromatin landscape compatible with RNA polymerase II transcription activation

2015-05-04 | GSE66542 | GEO

FGF2 antiproliferative stimulus triggers proteomic and transcriptional changes associated with nucleolar disorganization in K-ras-driven mouse tumor cells (Nucleoli TMT)

Project description:Chromatin plays a crucial role in the intermediation between cell signaling and gene expression. The nucleolus is sensitive to stress and can orchestrate a chain of cellular events in response to stress signals. Despite being a growth factor, FGF2 has anti-proliferative and tumor-suppressive functions in some cellular contexts. In this work, we investigated how the antiproliferative effect of FGF2 modulates chromatin, nucleolus, and rDNA-associated proteins. The chromatin and nucleolar proteome indicated that FGF2 stimulation modulates proteins related to transcription regulation, particularly rRNA expression, and chromatin remodeling proteins. Upon 24 hrs of FGF2 stimulation, the global transcriptional rate and nucleolus area increased in associationalong with intense nucleolar disorganization detected by fibrillarin dispersion and electron microscopy analyses. We confirmed that FGF2 stimulation induced immature rRNA accumulation by increasing rRNA transcription regardless of changes in ribosome profiling. The rDNA-associated protein analysis reinforced that FGF2 stimulus interferes with transcription and rRNA processing/modification, since the proteins Nolc1 and Tcof1 are were upregulated after FGF2 stimulation. Changes in rRNA expression may be crucial for triggering the antiproliferative effect induced by FGF2 since inhibiting RNA Pol I, responsible for rRNA expression, partially reversed the growth arrest induced by FGF2. Taken together, we demonstrate that the antiproliferative FGF2 stimulus triggers significant transcriptional changes, and modulation modulates of the main cell transcription site, the nucleolus, directly modulating the proteome of the rDNA loci.

2022-10-12 | MSV000090518 | MassIVE

FGF2 antiproliferative stimulus triggers proteomic and transcriptional changes associated with nucleolar disorganization in K-ras-driven mouse tumor cells (CLASP MudPIT data)

2022-10-12 | MSV000090516 | MassIVE

FGF2 antiproliferative stimulus triggers proteomic and transcriptional changes associated with nucleolar disorganization in K-ras-driven mouse tumor cells (Chromatin MudPIT data)

2022-10-11 | MSV000090511 | MassIVE

FGF2 antiproliferative stimulus triggers proteomic and transcriptional changes associated with nucleolar disorganization in K-ras-driven mouse tumor cells (Nucleoli proteome data)

Project description:Chromatin plays a crucial role in the intermediation between cell signaling and gene expression. The nucleolus is sensitive to stress and can orchestrate a chain of cellular events in response to stress signals. Despite being a growth factor, FGF2 has anti-proliferative and tumor-suppressive functions in some cellular contexts. In this work, we investigated how the antiproliferative effect of FGF2 modulates chromatin, nucleolus, and rDNA-associated proteins. The chromatin and nucleolar proteome indicated that FGF2 stimulation modulates proteins related to transcription regulation, particularly rRNA expression, and chromatin remodeling proteins. Upon 24 hrs of FGF2 stimulation, the global transcriptional rate and nucleolus area increased along with intense nucleolar disorganization detected by fibrillarin dispersion and electron microscopy analyses. We confirmed that FGF2 stimulation induced immature rRNA accumulation by increasing rRNA transcription regardless of changes in ribosome profiling. The rDNA-associated protein analysis reinforced that FGF2 stimulus interferes with transcription and rRNA processing/modification, since the proteins Nolc1 and Tcof1 were upregulated after FGF2 stimulation. Changes in rRNA expression may be crucial for triggering the antiproliferative effect induced by FGF2 since inhibiting RNA Pol I, responsible for rRNA expression, partially reversed the growth arrest induced by FGF2. Taken together, we demonstrate that the antiproliferative FGF2 stimulus triggers significant transcriptional changes and modulates the main cell transcription site, the nucleolus, directly modulating the proteome of the rDNA loci.

2024-09-28 | PXD037348 | Pride

RNA-Seq analysis of beta-actin knockout MEFs expressing NLS-tagged beta-actin

Project description:RNA-Seq analysis of beta-actin knockout MEFs expressing NLS-tagged beta-actin to study role of actin in transcription

2022-09-19 | GSE213433 | GEO

TFAM loss induces nuclear actin assembly upon mDia2 malonylation to promote liver cancer metastasis

Project description:The mechanisms underlying cancer metastasis remain poorly understood. Here, we report that TFAM deficiency rapidly and stably induced spontaneous lung metastasis in mice with liver cancer. Interestingly, unexpected polymerization of nuclear actin was observed in TFAM-knockdown HCC cells when cytoskeleton was examined. Polymerization of nuclear actin is causally linked to the high-metastatic ability of HCC cells by modulating chromatin accessibility and coordinating the expression of genes associated with extracellular matrix remodeling, angiogenesis, and cell migration. Mechanistically, TFAM deficiency blocked the TCA cycle and increased the intracellular malonyl-CoA levels. Malonylation of mDia2, which drives actin assembly, promotes its nuclear translocation. Importantly, inhibition of malonyl-CoA production or nuclear actin polymerization significantly impeded the spread of HCC cells in mice. Moreover, TFAM was significantly downregulated in metastatic HCC tissues and was associated with overall survival and time to tumor recurrence of HCC patients. Taken together, our study connects mitochondria to the metastasis of human cancer via uncovered mitochondria-to-nucleus retrograde signaling, indicating that TFAM may serve as an effective target to block HCC metastasis.

2022-06-23 | MTBLS4307 | MetaboLights

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data