Rb family proteins and Activator E2F family transcription factors are master regulators of the molecular signatures instructing the quiescent and activated adult neural stem cell state
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA788441 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:The long-term maintenance of the adult neurogenic niche and neurogenesis is dependent on the proper regulation of entry and exit from quiescence. The dynamic transition from quiescence to activation is a complex process requiring not only precise cell cycle control, but also a co-ordinated phenotypic transition involving transcriptional and morphological changes. Presently, the mechanisms by which such a complex repertoire of factors interact and co-ordinate with the core cell cycle machinery to mediate these critical NSC fate transitions remains unknown. Here we show that the Rb/E2F axis functions as an on-off switch for NSC quiescence and activation, by linking the cell cycle machinery to pivotal regulators of NSC fate. Compound deletion of Rb family proteins results in massive activation and expansion of NSCs, and induces a global transcriptomic transition towards NSC activation followed by niche depletion. Deletion of their target activator E2Fs1/3 results in the failure of NSCs to become activated and the acquisition of a global transcriptome associated with intractable NSC quiescence and the cessation of adult neurogenesis. We further show that the Rb/E2F axis orchestrates these fate transitions through the direct regulation of factors essential to NSC function, including REST and ASCL1. This places the Rb/E2F axis as a master regulator of NSC fate, coordinating cell cycle control with NSC activation and quiescence fate transitions.
2022-11-01 | GSE190764 | GEO
Project description:The long-term maintenance of the adult neurogenic niche and neurogenesis is dependent on the proper regulation of entry and exit from quiescence. The dynamic transition from quiescence to activation is a complex process requiring not only precise cell cycle control, but also a co-ordinated phenotypic transition involving transcriptional and morphological changes. Presently, the mechanisms by which such a complex repertoire of factors interact and co-ordinate with the core cell cycle machinery to mediate these critical NSC fate transitions remains unknown. Here we show that the Rb/E2F axis functions as an on-off switch for NSC quiescence and activation, by linking the cell cycle machinery to pivotal regulators of NSC fate. Compound deletion of Rb family proteins results in massive activation and expansion of NSCs, and induces a global transcriptomic transition towards NSC activation followed by niche depletion. Deletion of their target activator E2Fs1/3 results in the failure of NSCs to become activated and the acquisition of a global transcriptome associated with intractable NSC quiescence and the cessation of adult neurogenesis. We further show that the Rb/E2F axis orchestrates these fate transitions through the direct regulation of factors essential to NSC function, including REST and ASCL1. This places the Rb/E2F axis as a master regulator of NSC fate, coordinating cell cycle control with NSC activation and quiescence fate transitions.
2022-11-01 | GSE190765 | GEO
Project description:E2F transcription factors are central regulators of cell cycle progression and cell fate decisions in mammalian cells. E2F4 is a transcriptional repressor implicated in cell cycle arrest and whose repressive activity depends on its interaction with members of the RB family. E2F4 often represents the predominant E2F activity in cells. Here we show that E2F4 is important for the proliferation and the survival of mouse embryonic stem cells. In these cells, E2F4 acts in part as a transcriptional activator that promotes the expression of cell cycle genes. Importantly, this role for E2F4 is completely independent of the RB family. Accordingly, an unbiased analysis of the E2F4 interactome shows that E2F4 functionally interacts with chromatin regulators associated with gene activation in RB family-mutant cells. Taken together, our findings uncover a non-canonical role for E2F4 that reveal novel insights into the biology of rapidly dividing cell types.
2019-04-26 | PXD008796 | Pride
Project description:Mutations in cancer are due in part to DNA cytosine deamination by APOBEC3B (A3B). While low in healthy tissues, A3B expression and activity are elevated in tumors and further increase in metastases. However, molecular mechanisms responsible for A3B transcriptional regulation are poorly understood. Here, we address whether the RB/E2F pathway, which is often dysregulated in breast cancer, is a molecular trigger of A3B overexpression. First, an A3B promoter-driven luciferase reporter was used to demonstrate reporter activation by disruption of only one out of five predicted E2F binding sites. Second, A3B-luciferase reporter activation was also triggered by expressing the BK polyomavirus T-antigen, which inactivates RB and thereby alleviates repression of E2F regulated genes. Importantly, A3B-luciferase reporter induction by BK polyomavirus T-antigen could not be further increased by mutating the functional E2F binding site. Third, both CRISPR disruption and targeted base substitutions in the endogenous E2F binding site caused strong A3B upregulation and confirmed importance of this regulatory element. Fourth, proteomics experiments showed that members of the DREAM and PRC1.6-complexes including multiple E2F family members are able to bind to wild-type but not E2F mutant promoter sequences. Finally, a combination of genetic and biochemical studies implicated E2F4 and E2F6 in endogenous A3B gene repression. Altogether, our studies demonstrate that A3B expression is suppressed in normal cells by the RB/E2F axis and that viral or mutational disruption of this pathway causes overexpression of this DNA deaminase in cancer and contributes mutational fuel to tumor evolution.
2020-10-19 | PXD020473 | Pride
Project description:Activator E2F family transcription factors are master regulators of the molecular signatures instructing the quiescent and activated adult neural stem cell state
| PRJNA788446 | ENA
Project description:The Rb/E2F tumor suppressor regulates gene expression to control the onset and timing of differentiation in many different cell types during development. This critical function makes Rb/E2F a frequent target for inactivation in tumors of diverse tissue origin. However, the mechanisms by which Rb/E2F governs tissue-specific gene regulation in vivo are poorly understood. We have determined the genome-wide binding profiles for components of the C. elegans Rb/E2F transcriptional regulatory pathway in the germ line, the intestine, and broadly in somatic tissues. Rb/E2F exhibits highly tissue-specific regulation, with unique sets of target genes that are activated or repressed depending on whether cells are in a progenitor (germ line) or terminally differentiated (somatic) state. In particular, LIN-35 binding is impaired in the germ line relative to the soma. Moreover, in the intestine, LIN-35 binds independently of EFL-1/DPL-1 at broad intergenic sites at which the heterochromatin protein HPL-2 also binds. Finally, recently defined âHOTâ sites, which are non-specifically bound by many unrelated factors, appear to be restricted primarily to somatic tissues, suggesting that germ line chromatin is in a state that globally restricts promiscuous association of regulatory factors. In sum, these tissue-specific binding profiles led to significant mechanistic insights into tissue-specific properties of Rb/E2F function in C. elegans that are likely relevant to other organisms.
2012-06-26 | GSE30246 | GEO
Project description:Most E2F-binding sites repress transcription through the recruitment of Retinoblasoma (RB) family members until the end of the G1 cell-cycle phase. Although the MYB promoter contains an E2F-binding site, its transcription is activated shortly after the exit from quiescence, before RB family members inactivation, by unknown mechanisms. We had previously uncovered a nuclear factor distinct from E2F, Myb-sp, whose DNA-binding site overlapped the E2F element and had hypothesized that this factor might overcome the transcriptional repression of MYB by E2F-RB family members. We have purified Myb-sp and discovered that Myc-associated zinc finger proteins (MAZ) are major components. We show that various MAZ isoforms are present in Myb-sp and activate transcription via the MYB-E2F element. Moreover, while forced RB or p130 expression repressed the activity of a luciferase reporter driven by the MYB-E2F element, co-expression of MAZ proteins not only reverted repression, but also activated transcription. Finally, we show that MAZ binds the MYB promoter in vivo, that its binding site is critical for MYB transactivation, and that MAZ knockdown inhibits MYB expression during the exit from quiescence. Together, these data indicate that MAZ is essential to bypass MYB promoter repression by RB family members and to induce MYB expression.
2017-10-04 | PXD006857 | Pride
Project description:MiRNAs, which are a family of small non-coding RNAs, regulate a broad array of physiological and developmental processes. However, their regulatory roles have remained largely mysterious. E2F is a positive regulator of cell cycle progression and also a potent inducer of apoptosis. Positive feedback loops in the regulation of Rb-E2F pathway are predicted and shown experimentally. Recently, it has been discovered that E2F induce a cluster of miRNAs called miR449. In turn, E2F is inhibited by miR449 through regulating different transcripts, thus forming negative feedback loops in the interaction network. Here, based on the integration of experimental evidence and quantitative data, we studied Rb-E2F pathway coupling the positive feedback loops and negative feedback loops mediated by miR449. Therefore, a mathematical model is constructed based in part on the model proposed in Yao-Lee et al. (2008) and nonlinear dynamical behaviors including the stability and bifurcations of the model are discussed.
2024-09-02 | BIOMD0000000720 | BioModels
Project description:E2F transcription factors are central regulators of cell division and cell fate decisions. E2F4 often represents the predominant E2F activity in cells. E2F4 is a transcriptional repressor implicated in cell cycle arrest and whose repressive activity depends on its interaction with members of the RB family. Here we show that E2F4 is important for the proliferation and the survival of mouse embryonic stem cells. In these cells, E2F4 acts in part as a transcriptional activator that promotes the expression of cell cycle genes. This role for E2F4 is independent of the RB family. Accordingly, E2F4 functionally interacts with chromatin regulators associated with gene activation and we observed decreased histone acetylation at the promoters of cell cycle genes and E2F targets upon loss of E2F4 in RB family-mutant cells. Taken together, our findings uncover a non-canonical role for E2F4 that provide insights into the biology of rapidly dividing cells.
2019-04-25 | GSE109684 | GEO
Project description:Rb family proteins are master regulators of the molecular signatures instructing the quiescent and activated adult neural stem cell state
| PRJNA788447 | ENA