Nono, a novel bivalent domain factor, regulates Erk signaling and mouse embryonic stem cell pluripotency
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ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE86818 | GEO | 2016/10/18
SECONDARY ACCESSION(S): PRJNA342617
REPOSITORIES: GEO
Similar Datasets
Project description:Nono is a component of the para-speckle, which stores and processes RNA. Mouse embryonic stem cells (mESCs) lack para-speckles, leaving the function of Nono in mESCs unclear. Here, we find that Nono functions as a chromatin regulator cooperating with Erk to regulate mESC pluripotency. We report that Nono loss results in robust self-renewing mESCs with epigenomic and transcriptomic features resembling the 2i (GSK and Erk inhibitors)-induced "ground state." Erk interacts with and is required for Nono localization to a subset of bivalent genes that have high levels of poised RNA polymerase. Nono loss compromises Erk activation and RNA polymerase poising at its target bivalent genes in undifferentiated mESCs, thus disrupting target gene activation and differentiation. These findings argue that Nono collaborates with Erk signaling to regulate the integrity of bivalent domains and mESC pluripotency.
| S-EPMC5086807 | biostudies-literature
Project description:Here we report that Nono instead functions as a chromatin regulator cooperating with Erk to regulate mESC pluripotency. We demonstrate that Nono loss leads to robust self-renewing mESCs with enhanced expression of Nanog and Klf4, epigenome and transcriptome re-patterning to a “ground-like state” with global reduction of H3K27me3 and DNA methylation resembling the Erk inhibitor PD03 treated mESCs and 2i (both GSK and Erk kinase inhibitors)-induced “ground state”. Mechanistically, Nono and Erk co-bind at a subset of development-related, bivalent genes. Ablation of Nono compromises Erk activation and RNA polymerase II C-terminal Domain serine 5 phosphorylation, and while inactivation of Erk evicts Nono from chromatin, revealing reciprocal regulation. Furthermore, Nono loss results in a compromised activation of its target bivalent genes upon differentiation and the differentiation itself. These findings reveal an unanticipated role of Nono in collaborating with Erk signaling to regulate the integrity of bivalent domain and mESC pluripotency.
2016-10-18 | GSE86817 | GEO
Project description:Here we report that NONO, a nuclear para-speckle component, instead functions as a chromatin regulator in mESCs acting in the ERK signaling pathway to regulate the balance between ground state versus mESCs primed for differentiation. NONO loss increases a \u201cground-like\u201d population of mESCs favoring self-renewal and more resist to differentiation, partially mimicking the effects of 2i. Mechanistically, NONO and ERK mainly co-binds a subset of development related, bivalent genes. Importantly, NONO and ERK reciprocally regulate one another, i.e. NONO regulates ERK activation while ERK controls NONO chromatin association, forming a self-reinforcing feedback loop. Our findings thus reveal a cell intrinsic mechanism involving NONO and ERK, which impact the balance between self-renewal and differentiation, respectively.
2016-10-18 | GSE73426 | GEO
Project description:Nono, a novel bivalent domain factor, regulates Erk signaling and mouse embryonic stem cell pluripotency
| PRJNA342617 | ENA
Project description:The mechanisms of how signaling pathways are coordinated and integrated for the maintenance of the self-renewal of human embryonic stem cells (hESCs) and the acquisition of pluripotency in reprogramming are still only partly understood. CDK1 is a key regulator of mitosis. Recently, CDK1 has been shown to be involved in regulating self-renewal of stem cells, even though the mechanistic role of how CDK1 regulates pluripotency is unknown. In this report, we aim to understand how CDK1 can control pluripotency by reducing CDK1 activity to a level that has no effect on cell cycle progression. We demonstrated that high levels of CDK1 is associated with the pluripotency stage of hESCs; and decreased CDK1 activity to a level without perturbing the cell cycle is sufficient to induce differentiation. CDK1 specifically targets the phosphorylation of PDK1 and consequently the activity of PI3K/Akt and its effectors ERK and GSK3β. Evidence of the reversion of inactive CDK1-mediated differentiation by the inhibition of Akt signaling effectors suggests that the CDK1-PDK1-PI3K/Akt kinase cascade is a functional signaling pathway for the pluripotency of hESCs. Moreover, cyclin B1-CDK1 complexes promote somatic reprogramming efficiency, probably by regulating the maturation of induced pluripotent stem cells (iPSCs), as cyclin B1 stimulates a higher cellular level of LIN28A, suggesting that monitoring iPSC factors could be a new path for the enhancement of reprogramming efficiency. Together, we demonstrate an essential role for the CDK1-PDK1-PI3K/Akt kinase signaling pathway in the regulation of self-renewal, differentiation, and somatic reprogramming, which provides a novel kinase cascade mechanism for pluripotency control and acquisition.
| S-EPMC5260505 | biostudies-literature
Project description:An open and decondensed chromatin organization is a defining property of pluripotency. Several epigenetic regulators have been implicated in maintaining an open chromatin organization, but how these processes are connected to the pluripotency network is unknown. Here, we identified a new role for the transcription factor NANOG as a key regulator connecting the pluripotency network with constitutive heterochromatin organization in mouse embryonic stem cells. Deletion of Nanog leads to chromatin compaction and the remodeling of heterochromatin domains. Forced expression of NANOG in epiblast stem cells is sufficient to decompact chromatin. NANOG associates with satellite repeats within heterochromatin domains, contributing to an architecture characterized by highly dispersed chromatin fibers, low levels of H3K9me3, and high major satellite transcription, and the strong transactivation domain of NANOG is required for this organization. The heterochromatin-associated protein SALL1 is a direct cofactor for NANOG, and loss of Sall1 recapitulates the Nanog-null phenotype, but the loss of Sall1 can be circumvented through direct recruitment of the NANOG transactivation domain to major satellites. These results establish a direct connection between the pluripotency network and chromatin organization and emphasize that maintaining an open heterochromatin architecture is a highly regulated process in embryonic stem cells.
| S-EPMC4863740 | biostudies-literature
Project description:Members of the transforming growth factor-beta superfamily play essential roles in both the pluripotency and differentiation of embryonic stem (ES) cells. Although bone morphogenic proteins (BMPs) maintain pluripotency of undifferentiated mouse ES cells, the role of autocrine Nodal signaling is less clear. Pharmacological, molecular, and genetic methods were used to further understand the roles and potential interactions of these pathways. Treatment of undifferentiated ES cells with SB431542, a pharmacological inhibitor of Smad2 signaling, resulted in a rapid reduction of phosphorylated Smad2 and altered the expression of several putative downstream targets. Unexpectedly, inhibition of the Nodal signaling pathway resulted in enhanced BMP signaling, as assessed by Smad1/5 phosphorylation. SB431542-treated cells also demonstrated significant induction of the Id genes, which are known direct targets of BMP signaling and important factors in ES cell pluripotency. Inhibition of BMP signaling decreased the SB431542-mediated phosphorylation of Smad1/5 and induction of Id genes, suggesting that BMP signaling is necessary for some Smad2-mediated activity. Because Smad7, a known inhibitory factor to both Nodal and BMP signaling, was down-regulated following inhibition of Nodal-Smad2 signaling, the contribution of Smad7 to the cross-talk between the transforming growth factor-beta pathways in ES cells was examined. Biochemical manipulation of Smad7 expression, through shRNA knockdown or inducible gene expression, significantly reduced the SB431542-mediated phosphorylation of Smad1/5 and induction of the Id genes. We conclude that autocrine Nodal signaling in undifferentiated mouse ES cells modulates the vital pluripotency pathway of BMP signaling.
| S-EPMC2888385 | biostudies-literature
Project description:Here we show that bivalent domains and chromosome architecture for bivalent genes are dynamically regulated during the cell cycle in human pluripotent cells. Central to this is the transient increase in H3K4-trimethylation at developmental genes during G1, thereby creating a "window of opportunity" for cell-fate specification. This mechanism is controlled by CDK2-dependent phosphorylation of the MLL2 (KMT2B) histone methyl-transferase, which facilitates its recruitment to developmental genes in G1. MLL2 binding is required for changes in chromosome architecture around developmental genes and establishes promoter-enhancer looping interactions in a cell-cycle-dependent manner. These cell-cycle-regulated loops are shown to be essential for activation of bivalent genes and pluripotency exit. These findings demonstrate that bivalent domains are established to control the cell-cycle-dependent activation of developmental genes so that differentiation initiates from the G1 phase.
| S-EPMC4618451 | biostudies-literature
Project description:N6-methyladenosine (m6A) deposition on messenger RNA (mRNA) controls embryonic stem cell (ESC) fate by regulating the mRNA stabilities of pluripotency and lineage transcription factors (TFs) [P. J. Batista et al., Cell Stem Cell 15, 707-719 (2014); Y. Wang et al., Nat. Cell Biol. 16, 191-198 (2014); and S. Geula et al., Science 347, 1002-1006 (2015)]. If the mRNAs of these two TF groups become stabilized, it remains unclear how the pluripotency or lineage commitment decision is implemented. We performed noninvasive quantification of Nanog and Oct4 TF protein levels in reporter ESCs to define cell-state dynamics at single-cell resolution. Long-term single-cell tracking shows that immediate m6A depletion by Mettl3 knock-down in serum/leukemia inhibitory factor supports both pluripotency maintenance and its departure. This is mediated by differential and opposing signaling pathways. Increased FGF5 mRNA stability activates pErk, leading to Nanog down-regulation. FGF5-mediated coactivation of pAkt reenforces Nanog expression. In formative stem cells poised toward differentiation, m6A depletion activates both pErk and pAkt, increasing the propensity for mesendodermal lineage induction. Stable m6A depletion by Mettl3 knock-out also promotes pErk activation. Higher pErk counteracts the pluripotency exit delay exhibited by stably m6A-depleted cells upon differentiation. At single-cell resolution, we illustrate that decreasing m6A abundances activates pErk and pAkt-signaling, regulating pluripotency departure.
| S-EPMC8713808 | biostudies-literature
Project description:Although the functional roles of long noncoding RNAs (lncRNAs) have been increasingly identified, few lncRNAs that control the naïve state of embryonic stem cells (ESCs) are known. Here, we report a naïve-state-associated lncRNA, LincU, which is intrinsically activated by Nanog in mESCs. LincU-deficient mESCs exhibit a primed-like pluripotent state and potentiate the transition from the naïve state to the primed state, whereas ectopic LincU expression maintains mESCs in the naïve state. Mechanistically, we demonstrate that LincU binds and stabilizes the DUSP9 protein, an ERK-specific phosphatase, and then constitutively inhibits the ERK1/2 signaling pathway, which critically contributes to maintenance of the naïve state. Importantly, we reveal the functional role of LincU to be evolutionarily conserved in human. Therefore, our findings unveil LincU as a conserved lncRNA that intrinsically restricts MAPK/ERK activity and maintains the naïve state of ESCs.
| S-EPMC6092693 | biostudies-other