P53 transcription factor mediates nuclear speckle association of target genes
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA645124 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:Nuclear speckles are prominent nuclear bodies that contain a myriad of factors involved in gene expression. The role of nuclear speckles as activating transcriptional compartments is emerging. However, the extent that the association between speckles and DNA is regulatable, and the mechanisms that govern regulated speckle association are currently unclear. Using DNA- and RNA-FISH, we show that speckle association can be mediated by the p53 transcription factor, finding that p53 activation drives speckle association of specific p53 transcriptional targets. Analysis of a key p53 target, p21, revealed an increase in nascent transcripts at speckle-adjacent transcription sites, supporting a role for speckles in amplifying transcriptional output. Importantly, p53-regulated speckle association of p21 did not depend on transcriptional activation, demonstrating that speckle association is not merely a consequence of gene expression. In contrast, speckle association of p21 did require DNA binding functions of p53, providing a mechanism for the specificity by which speckle association is regulated. Beyond p21, a substantial subset of p53 targets have p53-regulated speckle association, while other p53 targets do not, and we find that genomic context is highly deterministic of which target genes have regulated speckle association. These findings reveal a novel means by which transcription factors may control gene expression and provide a mechanism for the specificity of regulated speckle association.
2021-01-04 | GSE154095 | GEO
Project description:Nuclear pore complexes (NPCs) are the central apparatus of nucleocytoplasmic transport. Disease-specific alterations of NPCs contribute to the pathogenesis of many cancers; however, the roles of NPCs in glioblastoma (GBM) are unknown. In this study, we report genomic amplification of NUP107, a component of NPCs, in GBM and show that NUP107 is overexpressed simultaneously with MDM2, a critical E3 ligase that mediates p53 degradation. Depletion of NUP107 inhibits the growth of GBM cell lines through p53 protein stabilization. Mechanistically, NPCs establish a p53 degradation platform via an export pathway coupled with 26S proteasome tethering. NUP107 is the keystone for NPC assembly; the loss of NUP107 affects the integrity of the NPC structure, and thus the proportion of 26S proteasome in the vicinity of nuclear pores significantly decreases. Together, our findings establish roles of NPCs in transport surveillance and provide insights into p53 inactivation in GBM.
2023-08-19 | GSE216888 | GEO
Project description:Recently, more than a thousand large intergenic non-coding RNAs (lincRNAs) have been reported. These RNAs are evolutionarily conserved in mammalian genomes and thus presumably function in diverse biological processes. Here, we report the identification of lincRNAs that are regulated by p53. One of these lincRNAs (lincRNA-p21) serves as a repressor in p53-dependent transcriptional responses. Inhibition of lincRNA-p21 affects the expression of hundreds of gene targets enriched for genes normally repressed by p53. The observed transcriptional repression by lincRNA-p21 is mediated through the physical association with hnRNP-K. This interaction is required for proper genomic localization of hnRNP-K at repressed genes and regulation of p53 mediated apoptosis. We propose a model whereby transcription factors activate lincRNAs that serve as key repressors by physically associating with repressive complexes and modulating their localization to sets of previously active genes. Gene expression profiles of different p53 inducible mouse embryonic fibroblasts (p53LSL/LSL MEFs) across different time points after DNA damage. A large intergenic noncoding RNA induced by p53 mediates global gene repression in the p53 transcriptional response. [1] MEF profiling: p53 LSL/LSL MEFs were treated with adenoCRE for p53 restoration or adenoGFP as control for 24h and treated with 500nM doxorubicin for the indicated times. [2] hnRNPKKD profiling: p53 LSL/LSL MEFs were treated with adenoCRE for p53 restoration for 24h, transfected with siRNA oligos targeting different transcripts for 24h and then treated with 100nM doxorubicin for 13h. [3] lincP21KD profiling: p53 LSL/LSL MEFs were treated with adenoCRE for p53 restoration for 24h, transfected with siRNA oligos targeting different transcripts for 24h and then treated with 100nM doxorubicin for 13h. [4] RAS profiling: For p53 restoration, cultured tumor cell lines were incubated with 500nM 4-hydroxytamoxifen for the indicated times.
2010-08-09 | E-GEOD-21761 | biostudies-arrayexpress
Project description:Autophagy is a catabolic membrane trafficking process involved in degradation of cellular constituents through lysosomes, which maintains cell and tissue homeostasis. While much attention has been focused on autophagic turnover of cytoplasmic materials, little is known regarding the role of autophagy in degrading nuclear components. Here we report that autophagy machinery mediates degradation of nuclear lamina in mammalian cells, a process we term laminophagy. The autophagy protein LC3 is present in the nucleus and directly interacts with the nuclear lamina protein Lamin B1, and associates with lamin-associated domains (LADs) on chromatin. This interaction does not downregulate Lamin B1 during starvation, but mediates nuclear lamina degradation upon tumorigenic insults, such as by oncogenic Ras. Laminophagy is achieved by nucleus-to-cytosol transport that delivers Lamin B1 to lysosome for degradation. Inhibiting autophagy or LC3-Lamin B1 interaction prevents oncogenic Ras-induced Lamin B1 loss and delays oncogene-induced cell cycle arrest. Our study unveils a role of autophagy in degrading nuclear materials, and suggests laminophagy as a guarding mechanism protecting cells from tumorigenesis.
2015-10-08 | GSE63440 | GEO
Project description:Emergency myelopoiesis (EM) is critical for immune defense against pathogens, which requires rapid replenishing of mature myeloid cells. The EM process involves a rapid cell cycle switch from the quiescent hematopoietic stem cells (HSCs) to highly proliferative myeloid progenitors (MPs). How this cell cycle switch is regulated remains poorly understood. Here, we reveal that ATG7, a critical autophagy factor is essential for the rapid proliferation of MPs during human myelopoiesis. Peripheral blood (PB) mobilized HSPCs with ATG7 knock-down or HSPCs derived from ATG7-/- human embryonic stem cells (hESCs) exhibit severe defect in proliferation at MP stage during myeloid/granulocytes differentiation. ATG7 deficient MPs show substantially elevated P53 protein and up-regulation of P53 signaling pathway genes. Mechanistically, ATG7 dependent autophagy mediates P53 degradation in lysosome that allows normal proliferation of MPs. Together, we reveal an essential role of autophagy for P53 degradation in cell cycle switch during human myelopoiesis
2023-01-25 | GSE223219 | GEO
Project description:Long-distance association of topological boundaries through nuclear condensates
| PRJNA801249 | ENA
Project description:Transcriptional profiling of Esophageal Squamous Cell Carcinoma (ESCC) tumors comparing samples harbouring nuclear-stabilized p53 (NS+) versus unstable p53 (NS-) protein, determined through immunohistochemistry (IHC) staining of the tumor sections. The goal was to identify the genes that were differentially regulated between NS+ and NS- ESCC samples.
2024-03-29 | GSE218109 | GEO
Project description:Cancer-relevant signalling pathways rely on bidirectional nucleocytoplasmic transport events through the nuclear pore complex (NPC). However, mechanisms by which individual NPC components (Nups) participate in the regulation of these pathways remain poorly understood. We discovered by integrating large scale proteomics, polysome fractionation and a focused RNAi approach that Nup155 controls mRNA translation of p21 (CDKN1A), a key mediator of the p53 response. The underlying mechanism involves transcriptional regulation of the putative tRNA and rRNA methyltransferase FTSJ1 by Nup155. Furthermore, we observed that Nup155 and FTSJ1 are p53 repression targets and accordingly found a correlation between the p53 status, Nup155 and FTSJ1 expression in murine and human hepatocellular carcinoma (HCC). Our data suggest an unanticipated regulatory network linking translational control by and repression of a structural NPC component modulating the p53 pathway through its effectors.
2019-04-09 | PXD012373 | Pride
Project description:Recently, more than a thousand large intergenic non-coding RNAs (lincRNAs) have been reported. These RNAs are evolutionarily conserved in mammalian genomes and thus presumably function in diverse biological processes. Here, we report the identification of lincRNAs that are regulated by p53. One of these lincRNAs (lincRNA-p21) serves as a repressor in p53-dependent transcriptional responses. Inhibition of lincRNA-p21 affects the expression of hundreds of gene targets enriched for genes normally repressed by p53. The observed transcriptional repression by lincRNA-p21 is mediated through the physical association with hnRNP-K. This interaction is required for proper genomic localization of hnRNP-K at repressed genes and regulation of p53 mediated apoptosis. We propose a model whereby transcription factors activate lincRNAs that serve as key repressors by physically associating with repressive complexes and modulating their localization to sets of previously active genes.
2010-08-09 | GSE21761 | GEO
Project description:The control of p53 protein stability is critical to its tumor suppressor functions. The CREB Binding Protein (CBP) transcriptional coactivator co-operates with MDM2 to maintain normally low physiologic p53 levels in cells via an exclusively cytoplasmic ‘E4’ polyubiquitination activity. Utilizing mass spectrometry to identify nuclear and cytoplasmic CBP interacting proteins that regulate compartmentalized CBP E4 activity, we identified Deleted in Breast Cancer 1 (DBC1) as a stoichiometric CBP-interacting protein that negatively regulates CBP–dependent p53 polyubiquitination, stabilizes p53, and augments p53-dependent apoptosis. TCGA analysis demonstrated that solid tumors often retain wild type p53 alleles in conjunction with DBC1 loss, supporting the hypothesis that DBC1 is selected for disruption during carcinogenesis as a surrogate for p53 functional loss. As DBC1 maintains p53 stability in the nucleus where p53 exerts its tumor suppressive transcriptional function, replacement of DBC1 functionality in DBC1-deleted tumors might also enhance p53 function and chemosensitivity for therapeutic benefit.
2019-11-13 | PXD012673 | Pride