Comparing active and repressed expression states of genes controlled by the Polycomb/Trithorax group proteins

Beisel, Christian; Buneß, Andreas; Roustan-Espinosa, Ian M; Koch, Britta; Schmitt, Sabine; Haas, Stefan A.; Hild, Marc; Katsuyama, Tomonori; Paro, Renato

doi:10.1073/pnas.0701538104

Cited by 70 publications

(83 citation statements)

References 52 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…S5). These findings are consistent with genome-wide studies showing that both proteins preferentially localize to PREs but are not found at high levels elsewhere in silenced domains (19,26,29,30). We next examined the association of PH and dSfmbt under conditions in which constitutive expression of GAL4 from the tubulin promoter disrupts the silencing activity of the bxdPRE.…”

Section: Transcriptional Read-through Reduces But Does Not Eliminate supporting

confidence: 75%

“…PcG repression is associated with a competition with TrxG proteins (4). For example, it was shown that Trx could be recruited to PREs in both activating and in repressing states (26,29). Another factor-GAF protein-was originally identified as a TrxG member (32); however, further studies indicated involvement of GAF in PRE-silencing function (33)(34)(35)(36)(37).…”

Section: Pc (Prc1) and H3k27me3 Remain Associated With Bxdpre In Thementioning

confidence: 99%

See 1 more Smart Citation

Transcriptional read-through is not sufficient to induce an epigenetic switch in the silencing activity of Polycomb response elements

Erokhin

Elizar’ev

Parshikov

et al. 2015

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

In Drosophila, Polycomb (PcG) and Trithorax (TrxG) group proteins are assembled on Polycomb response elements (PREs) to maintain tissue and stage-specific patterns of gene expression. Critical to coordinating gene expression with the process of differentiation, the activity of PREs can be switched "on" and "off." When on, the PRE imposes a silenced state on the genes in the same domain that is stably inherited through multiple rounds of cell division. When the PRE is switched off, the domain is in a state permissive for gene expression that can be stably inherited. Previous studies have suggested that a burst of transcription through a PRE sequence displaces PcG proteins and provides a universal mechanism for inducing a heritable switch in PRE activity from on to off; however, the evidence favoring this model is indirect. Here, we have directly tested the transcriptional read-through mechanism. Contrary to previous suggestions, we show that transcription through the PRE is not sufficient for inducing an epigenetic switch in PRE activity. In fact, even high levels of continuous transcription through a PRE fails to dislodge the PcG proteins, nor does it remove repressive histone marks. Our results indicate that other mechanisms involving adjacent DNA regulatory elements must be implicated in heritable switch of PRE activity.Polycomb | chromatin silencing | bithorax | intergenic transcription | Trithorax

show abstract

Section: Transcriptional Read-through Reduces But Does Not Eliminate supporting

confidence: 75%

Section: Pc (Prc1) and H3k27me3 Remain Associated With Bxdpre In Thementioning

confidence: 99%

Transcriptional read-through is not sufficient to induce an epigenetic switch in the silencing activity of Polycomb response elements

Erokhin

Elizar’ev

Parshikov

et al. 2015

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

show abstract

“…Genome-wide mapping of sites occupied by Polycomb proteins and H3K27me3 in S2 cells by chromatin immunoprecipitation combined with genome tiling arrays (ChIP-chip) has identified several hundred putative direct targets of Polycomb silencing (10,37,38). Genes with well-documented roles in modulating longevity are not among these direct targets (e.g., Sir2, Rpd3, foxo, InR, and others).…”

Section: Resultsmentioning

confidence: 99%

Polycomb Repressive Complex 2 and Trithorax modulate Drosophila longevity and stress resistance

Siebold¹,

Banerjee²,

Tie³

et al. 2009

Proc. Natl. Acad. Sci. U.S.A.

177

149

View full text Add to dashboard Cite

Polycomb Group (PcG) and Trithorax Group (TrxG) proteins are key epigenetic regulators of global transcription programs. Their antagonistic chromatin-modifying activities modulate the expression of many genes and affect many biological processes. Here we report that heterozygous mutations in two core subunits of Polycomb Repressive Complex 2 (PRC2), the histone H3 lysine 27 (H3K27)-specific methyltransferase E(Z) and its partner, the H3 binding protein ESC, increase longevity and reduce adult levels of trimethylated H3K27 (H3K27me3). Mutations in trithorax (trx), a well known antagonist of Polycomb silencing, elevate the H3K27me3 level of E(z) mutants and suppress their increased longevity. Like many long-lived mutants, E(z) and esc mutants exhibit increased resistance to oxidative stress and starvation, and these phenotypes are also suppressed by trx mutations. This suppression strongly suggests that both the longevity and stress resistance phenotypes of PRC2 mutants are specifically due to their reduced levels of H3K27me3 and the consequent perturbation of Polycomb silencing. Consistent with this, long-lived E(z) mutants exhibit derepression of Abd-B, a well-characterized direct target of Polycomb silencing, and Odc1, a putative direct target implicated in stress resistance. These findings establish a role for PRC2 and TRX in the modulation of organismal longevity and stress resistance and indicate that moderate perturbation of Polycomb silencing can increase longevity.aging | epigenetics | histone methyltransferase | Polycomb silencing

show abstract

“…This RNA-DNA recognition model requires only one strand of the recruiting RNA to be transcribed, as is the case for many of the PRE/TRE transcripts that have been studied (Table 1). On the other hand for several PRE/TREs, non-coding transcription is detectable from both strands (Table 1), 22,25,28,48 raising the interesting possibility of an RNA-RNA recognition mechanism, as shown in Figure 2D. In this model, a free RNA strand binds to PcG or TrxG proteins, and anneals back to a nascent transcript of complementary sequence, transcribed from the same site.…”

Section: Non-coding Transcription and Pcg/trxg Target Gene Silencing:mentioning

confidence: 99%

“…1C) the TrxG proteins gain the upper hand, H3K27 methylation is lost or reduced, and H3K4 methylation is increased. 5,8,16,24,25 In differentiated cells, many non-coding PRE/TRE transcripts have been observed to correlate temporally and spatially with activation of their cognate genes (Table 1), and these may thus contribute to the switch of an undecided PRE/TRE to the stably active state. However, there are also examples of non coding transcripts that correlate with the silenced state (Table 1).…”

Section: Introductionmentioning

confidence: 99%

Non-coding RNAs in Polycomb/Trithorax regulation

Hekimoglu¹,

Ringrose²

2009

RNA Biology

View full text Add to dashboard Cite

Comparing active and repressed expression states of genes controlled by the Polycomb/Trithorax group proteins

Cited by 70 publications

References 52 publications

Transcriptional read-through is not sufficient to induce an epigenetic switch in the silencing activity of Polycomb response elements

Transcriptional read-through is not sufficient to induce an epigenetic switch in the silencing activity of Polycomb response elements

Polycomb Repressive Complex 2 and Trithorax modulate Drosophila longevity and stress resistance

Non-coding RNAs in Polycomb/Trithorax regulation

Contact Info

Product

Resources

About