scholarly journals Three classes of response elements for human PRC2 and MLL1/2-trithorax complexes

2017 ◽  
Author(s):  
Junqing Du ◽  
Brian Kirk ◽  
Jia Zeng ◽  
Jianpeng Ma ◽  
Qinghua Wang
Keyword(s):  
Target Genes ◽  
Cpg Islands ◽  
Embryonic Stem ◽  
Polycomb Group ◽  
Epigenetic Memory ◽  
Trithorax Group ◽  
Response Elements ◽  
Differentiated Cells ◽  
Dna Elements ◽  
First Time

SummaryPolycomb group (PcG) and trithorax group (TrxG) proteins are essential for maintaining epigenetic memory in both embryonic stem cells and differentiated cells. To date, how they are localized to hundreds of specific target genes within a vertebrate genome had remained elusive. Here, by focusing on short cis-acting DNA elements of single functions, we discovered, for the first time, to our knowledge, three classes of response elements in human genome: PcG response elements (PREs), MLL1/2-TrxG response elements (TREs) and PcG/TrxG response elements (P/TREs). We further demonstrated that, in contrast to their proposed roles in recruiting PcG proteins to PREs, YY1 and CpG islands are specifically enriched in TREs and P/TREs, but not in PREs. The three classes of response elements as unraveled in this study open new doors for a deeper understanding of PcG and TrxG mechanisms in vertebrates.

scholarly journals Spatial Interplay between Polycomb and Trithorax Complexes Controls Transcriptional Activity in T Lymphocytes

2015 ◽  
Vol 35 (22) ◽  
pp. 3841-3853 ◽  
Author(s):  
Atsushi Onodera ◽  
Damon J. Tumes ◽  
Yukiko Watanabe ◽  
Kiyoshi Hirahara ◽  
Atsushi Kaneda ◽  
...  
Keyword(s):  
T Lymphocytes ◽  
Developmental Change ◽  
T Cell Development ◽  
Embryonic Stem ◽  
Polycomb Group ◽  
Trithorax Group ◽  
Differentiated Cells ◽  
Enhanced Sensitivity ◽  
Genome Wide ◽  
Lower Expression

Trithorax group (TrxG) and Polycomb group (PcG) proteins are two mutually antagonistic chromatin modifying complexes, however, how they together mediate transcriptional counter-regulation remains unknown. Genome-wide analysis revealed that binding of Ezh2 and menin, central members of the PcG and TrxG complexes, respectively, were reciprocally correlated. Moreover, we identified a developmental change in the positioning of Ezh2 and menin in differentiated T lymphocytes compared to embryonic stem cells. Ezh2-binding upstream and menin-binding downstream of the transcription start site was frequently found at genes with higher transcriptional levels, and Ezh2-binding downstream and menin-binding upstream was found at genes with lower expression in T lymphocytes. Interestingly, of the Ezh2 and menin cooccupied genes, those exhibiting occupancy at the same position displayed greatly enhanced sensitivity to loss of Ezh2. Finally, we also found that different combinations of Ezh2 and menin occupancy were associated with expression of specific functional gene groups important for T cell development. Therefore, spatial cooperative gene regulation by the PcG and TrxG complexes may represent a novel mechanism regulating the transcriptional identity of differentiated cells.

white+ Transgene Insertions Presenting a Dorsal/Ventral Pattern Define a Single Cluster of Homeobox Genes That Is Silenced by the Polycomb-group Proteins in Drosophila melanogaster

Genetics ◽  
1998 ◽  
Vol 149 (1) ◽  
pp. 257-275 ◽  
Author(s):  
Sophie Netter ◽  
Marie-Odile Fauvarque ◽  
Ruth Diez del Corral ◽  
Jean-Maurice Dura ◽  
Dario Coen
Keyword(s):  
Chromatin Structure ◽  
Target Genes ◽  
Position Effect ◽  
Phenotypic Expression ◽  
Positional Information ◽  
Genomic Region ◽  
Polycomb Group ◽  
Position Effect Variegation ◽  
Trithorax Group ◽  
Clear Cut

AbstractWe used the white gene as an enhancer trap and reporter of chromatin structure. We collected white+ transgene insertions presenting a peculiar pigmentation pattern in the eye: white expression is restricted to the dorsal half of the eye, with a clear-cut dorsal/ventral (D/V) border. This D/V pattern is stable and heritable, indicating that phenotypic expression of the white reporter reflects positional information in the developing eye. Localization of these transgenes led us to identify a unique genomic region encompassing 140 kb in 69D1–3 subject to this D/V effect. This region contains at least three closely related homeobox-containing genes that are constituents of the iroquois complex (IRO-C). IRO-C genes are coordinately regulated and implicated in similar developmental processes. Expression of these genes in the eye is regulated by the products of the Polycomb -group (Pc-G) and trithorax-group (trx-G) genes but is not modified by classical modifiers of position-effect variegation. Our results, together with the report of a Pc -G binding site in 69D, suggest that we have identified a novel cluster of target genes for the Pc-G and trx-G products. We thus propose that ventral silencing of the whole IRO-C in the eye occurs at the level of chromatin structure in a manner similar to that of the homeotic gene complexes, perhaps by local compaction of the region into a heterochromatin-like structure involving the Pc-G products.

scholarly journals Differential roles of trithorax protein MLL-1 in regulating neuronal Ion channels

2021 ◽  
Vol 5 (2) ◽  
Author(s):  
Dave Sonya ◽  
Zhou An
Keyword(s):  
Ion Channels ◽  
Potassium Channel ◽  
Polycomb Group ◽  
Channel Activity ◽  
Sodium Currents ◽  
Trithorax Group ◽  
Channel Protein ◽  
Trxg Protein ◽  
First Time ◽  
Potassium Channel Activity

Repressive regulation of potassium channel genes by Polycomb group (PcG) proteins contributes to PcG protein-mediated neuroprotection against neuronal ischemic injury, as seen in an ischemic stroke. Here we asked the question whether Trithorax group (TrxG) proteins, the antagonistic partners of PcG proteins (i.e, epigenetic activators targeting the same genes) may also regulate potassium channels. Results of patch-clamp studies on cultured neuronal cells showed that inhibition of TrxG protein MLL-1 led to an increase in potassium channel activity, an unexpected effect for a presumed gene activator. In contrast, decreased sodium currents were observed with MLL-1 inhibition. Increased or decreased levels of potassium channel protein Kv2.1 or sodium channel protein Nav1.2, respectively, were seen with MLL-1 inhibition, as determined by immunocytochemistry. These results, for the first time, demonstrate an involvement of TrxG protein MLL-1 in regulating neuronal ion channels, potentially repressing potassium channel genes.

scholarly journals PROSER1 mediates TET2 O-GlcNAcylation to regulate DNA demethylation on UTX-dependent enhancers and CpG islands

2021 ◽  
Vol 5 (1) ◽  
pp. e202101228
Author(s):  
Xiaokang Wang ◽  
Wojciech Rosikiewicz ◽  
Yurii Sedkov ◽  
Tanner Martinez ◽  
Baranda S Hansen ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Target Genes ◽  
Cpg Islands ◽  
Dna Demethylation ◽  
Dna Hypermethylation ◽  
Genome Wide ◽  
Associated Proteins ◽  
Tet Enzymes ◽  
Tet Protein ◽  
First Time

DNA methylation at enhancers and CpG islands usually leads to gene repression, which is counteracted by DNA demethylation through the TET protein family. However, how TET enzymes are recruited and regulated at these genomic loci is not fully understood. Here, we identify TET2, the glycosyltransferase OGT and a previously undescribed proline and serine rich protein, PROSER1 as interactors of UTX, a component of the enhancer-associated MLL3/4 complexes. We find that PROSER1 mediates the interaction between OGT and TET2, thus promoting TET2 O-GlcNAcylation and protein stability. In addition, PROSER1, UTX, TET1/2, and OGT colocalize on many genomic elements genome-wide. Loss of PROSER1 results in lower enrichment of UTX, TET1/2, and OGT at enhancers and CpG islands, with a concomitant increase in DNA methylation and transcriptional down-regulation of associated target genes and increased DNA hypermethylation encroachment at H3K4me1-predisposed CpG islands. Furthermore, we provide evidence that PROSER1 acts as a more general regulator of OGT activity by controlling O-GlcNAcylation of multiple other chromatin signaling pathways. Taken together, this study describes for the first time a regulator of TET2 O-GlcNAcylation and its implications in mediating DNA demethylation at UTX-dependent enhancers and CpG islands and supports an important role for PROSER1 in regulating the function of various chromatin-associated proteins via OGT-mediated O-GlcNAcylation.

scholarly journals Retinoic Acid Receptor Isotype Specificity in F9 Teratocarcinoma Stem Cells Results from the Differential Recruitment of Coregulators to Retinoic Acid Response Elements

2007 ◽  
Vol 282 (46) ◽  
pp. 33421-33434 ◽  
Author(s):  
Robert F. Gillespie ◽  
Lorraine J. Gudas
Keyword(s):  
Stem Cells ◽  
Retinoic Acid ◽  
Target Genes ◽  
Retinoic Acid Receptor ◽  
Polycomb Group ◽  
Polycomb Group Protein ◽  
Response Elements ◽  
Acid Receptor ◽  
Group Protein ◽  
F9 Teratocarcinoma

The retinoic acid receptor (RAR) α, β2, and γ isotypes each regulate specific subsets of target genes in F9 teratocarcinoma stem cells. We used chromatin immunoprecipitation assays to monitor the association of RARγ, retinoic X receptor (RXR) α, and coregulators with the RARβ2, Hoxa1, and Cyp26A1 retinoic acid response elements (RAREs) in F9 wild type and RARα, -β2, and -γ null cells. Additionally we quantitatively monitored expression of the corresponding mRNAs. We demonstrated that the association of RARγ and/or RXRα with a RARE was not sufficient for retinoic acid (RA)-mediated transcription of the corresponding target gene. However, the ability of RARγ and/or RXRα to recruit pCIP (AIB1/ACTR/RAC-3/TRAM-1/SRC-3) and p300 to a RARE did correlate with RA-associated transcription of target mRNAs. Therefore, the specific functions of the RAR isotypes do not manifest at the level of their DNA binding but rather from a differential ability to recruit specific components of the transcriptional machinery. We also demonstrated that RA-mediated displacement of the polycomb group protein SUZ12 from a RARE was inhibited in the absence of RARγ. Thus, transcriptional components of the RAR signaling pathway are specifically required for displacement of SUZ12 from RAREs during RA-mediated differentiation of F9 cells.

scholarly journals Klf4 Cooperates with Oct3/4 and Sox2 To Activate the Lefty1 Core Promoter in Embryonic Stem Cells

2006 ◽  
Vol 26 (20) ◽  
pp. 7772-7782 ◽  
Author(s):  
Yuhki Nakatake ◽  
Nobutaka Fukui ◽  
Yuko Iwamatsu ◽  
Shinji Masui ◽  
Kadue Takahashi ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Target Genes ◽  
Core Promoter ◽  
Es Cells ◽  
Embryonic Stem ◽  
Functional Screening ◽  
Transactivation Domain ◽  
Enhancer Element ◽  
Differentiated Cells ◽  
Promoter Dna

ABSTRACT Although the POU transcription factor Oct3/4 is pivotal in maintaining self renewal of embryonic stem (ES) cells, little is known of its molecular mechanisms. We previously reported that the N-terminal transactivation domain of Oct3/4 is required for activation of Lefty1 expression (H. Niwa, S. Masui, I. Chambers, A. G. Smith, and J. Miyazaki, Mol. Cell. Biol. 22:1526-1536, 2002). Here we test whether Lefty1 is a direct target of Oct3/4. We identified an ES cell-specific enhancer upstream of the Lefty1 promoter that contains binding sites for Oct3/4 and Sox2. Unlike other known Oct3/4-Sox2-dependent enhancers, however, this enhancer element could not be activated by Oct3/4 and Sox2 in differentiated cells. By functional screening of ES-specific transcription factors, we found that Krüppel-like factor 4 (Klf4) cooperates with Oct3/4 and Sox2 to activate Lefty1 expression, and that Klf4 acts as a mediating factor that specifically binds to the proximal element of the Lefty1 promoter. DNA microarray analysis revealed that a subset of putative Oct3/4 target genes may be regulated in the same manner. Our findings shed light on a novel function of Oct3/4 in ES cells.

TheDrosophilaTrithorax protein is a coactivator required to prevent re-establishment of Polycomb silencing

Development ◽  
2002 ◽  
Vol 129 (10) ◽  
pp. 2483-2493 ◽  
Author(s):  
Sylvain Poux ◽  
Béatrice Horard ◽  
Christian J. A. Sigrist ◽  
Vincenzo Pirrotta
Keyword(s):  
Imaginal Discs ◽  
Polycomb Group ◽  
Active State ◽  
Homeotic Genes ◽  
Epigenetic Memory ◽  
Gaga Factor ◽  
Response Elements ◽  
Active Gene ◽  
Polycomb Response Elements

Polycomb group (PcG) and Trithorax (TRX) complexes assemble at Polycomb response elements (PREs) and maintain respectively the repressed and active state of homeotic genes. Although PcG and TRX complexes are distinct, their binding to some PRE fragments in vitro depends on GAGA motifs. GAGA factor immunoprecipitates with both complexes. In presence of a PRE, TRX stimulates expression and prevents the return of repression at later stages. When TRX levels are reduced, repression is re-established in inappropriate regions of imaginal discs, suggesting that TRX insufficiency impairs the epigenetic memory of the active state. Targeting a GAL-TRX fusion shows that TRX is a coactivator that stimulates expression of an active gene but cannot initiate expression by itself. Targeting a histone acetylase to a PRE does not affect embryonic silencing but causes a loss of memory in imaginal discs, suggesting that deacetylation is required to establish the memory of the repressed state.

scholarly journals iPSC Preparation and Epigenetic Memory: Does the Tissue Origin Matter?

Cells ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1470
Author(s):  
Giuseppe Scesa ◽  
Raffaella Adami ◽  
Daniele Bottai
Keyword(s):  
Stem Cells ◽  
Molecular Mechanisms ◽  
Embryonic Stem ◽  
Epigenetic Memory ◽  
Differentiated Cells ◽  
Ipsc Generation ◽  
Tissue Of Origin ◽  
Induced Pluripotent ◽  
The Impact

The production of induced pluripotent stem cells (iPSCs) represent a breakthrough in regenerative medicine, providing new opportunities for understanding basic molecular mechanisms of human development and molecular aspects of degenerative diseases. In contrast to human embryonic stem cells (ESCs), iPSCs do not raise any ethical concerns regarding the onset of human personhood. Still, they present some technical issues related to immune rejection after transplantation and potential tumorigenicity, indicating that more steps forward must be completed to use iPSCs as a viable tool for in vivo tissue regeneration. On the other hand, cell source origin may be pivotal to iPSC generation since residual epigenetic memory could influence the iPSC phenotype and transplantation outcome. In this paper, we first review the impact of reprogramming methods and the choice of the tissue of origin on the epigenetic memory of the iPSCs or their differentiated cells. Next, we describe the importance of induction methods to determine the reprogramming efficiency and avoid integration in the host genome that could alter gene expression. Finally, we compare the significance of the tissue of origin and the inter-individual genetic variation modification that has been lightly evaluated so far, but which significantly impacts reprogramming.

scholarly journals Variant PCGF1-PRC1 links PRC2 recruitment with differentiation-associated transcriptional inactivation at target genes

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Hiroki Sugishita ◽  
Takashi Kondo ◽  
Shinsuke Ito ◽  
Manabu Nakayama ◽  
Nayuta Yakushiji-Kaminatsui ◽  
...  
Keyword(s):  
Stem Cells ◽  
Crucial Role ◽  
Target Genes ◽  
Embryonic Stem ◽  
Embryoid Bodies ◽  
Polycomb Group ◽  
Gene Repression ◽  
Down Regulation ◽  
Aberrant Expression ◽  
Polycomb Repressive Complexes

AbstractPolycomb repressive complexes-1 and -2 (PRC1 and 2) silence developmental genes in a spatiotemporal manner during embryogenesis. How Polycomb group (PcG) proteins orchestrate down-regulation of target genes upon differentiation, however, remains elusive. Here, by differentiating embryonic stem cells into embryoid bodies, we reveal a crucial role for the PCGF1-containing variant PRC1 complex (PCGF1-PRC1) to mediate differentiation-associated down-regulation of a group of genes. Upon differentiation cues, transcription is down-regulated at these genes, in association with PCGF1-PRC1-mediated deposition of histone H2AK119 mono-ubiquitination (H2AK119ub1) and PRC2 recruitment. In the absence of PCGF1-PRC1, both H2AK119ub1 deposition and PRC2 recruitment are disrupted, leading to aberrant expression of target genes. PCGF1-PRC1 is, therefore, required for initiation and consolidation of PcG-mediated gene repression during differentiation.

Sign in / Sign up

Export Citation Format

Share Document