scholarly journals Force-induced gene up-regulation does not follow the weak power law but depends on H3K9 demethylation

2020 ◽  
Vol 6 (14) ◽  
pp. eaay9095 ◽  
Author(s):  
Jian Sun ◽  
Junwei Chen ◽  
Erfan Mohagheghian ◽  
Ning Wang

Mechanical forces play important roles in development, physiology, and diseases, but how force is transduced into gene transcription remains elusive. Here, we show that transcription of transgene DHFR or endogenous genes egr-1 and Cav1 is rapidly up-regulated in response to cyclic forces applied via integrins at low frequencies but not at 100 Hz. Gene up-regulation does not follow the weak power law with force frequency. Force-induced transcription up-regulation at the nuclear interior is associated with demethylation of histone H3 lysine-9 trimethylation (H3K9me3), whereas no transcription up-regulation near the nuclear periphery is associated with H3K9me3 that inhibits Pol II recruitment to the promoter site. H3K9me3 demethylation induces Pol II recruitment and increases force-induced transcription of egr-1 and Cav1 at the nuclear interior and activates mechano-nonresponsive gene FKBP5 near the nuclear periphery, whereas H3K9me3 hypermethylation has opposite effects. Our findings demonstrate that rapid up-regulation of endogenous mechanoresponsive genes depends on H3K9me3 demethylation.

2010 ◽  
Vol 24 (4) ◽  
pp. 779-789 ◽  
Author(s):  
Dennis J. Chia ◽  
Jennifer J. Young ◽  
April R. Mertens ◽  
Peter Rotwein

Abstract Many of the physiological actions of GH are mediated by IGF-I, a secreted 70-residue peptide whose gene expression is induced by GH in the liver and other tissues via mechanisms that remain incompletely characterized but depend on the transcription factor Stat5b. Here we investigate the chromatin landscape of the IGF-I gene in the liver of pituitary-deficient young adult male rats and assess the impact of a single systemic GH injection. Despite minimal ongoing transcription in the absence of GH, both IGF-I promoters appear to reside in open chromatin environments, at least as inferred from relatively high levels of acetylation of core histones H3 and H4 when compared with adjacent intergenic DNA and from enhanced trimethylation of histone H3 at lysine 4. This landscape of open chromatin may reflect maturation of the liver. Surprisingly, in the absence of hormone, IGF-I promoter 1 appears poised to be activated, as evidenced by the presence of the transcriptional coactivator p300 and recruitment of RNA polymerase (Pol) II into a preinitiation complex. By contrast, chromatin surrounding IGF-I promoter 2 is devoid of both p300 and RNA Pol II. Systemic GH treatment causes an approximately 15-fold increase in transcription from each IGF-I promoter within 60 min of hormone administration, leading to a sustained accumulation of IGF-I mRNA. The coordinated induction of both IGF-I promoters by GH is accompanied by hyperacetylation of histones H3 and H4 in promoter-associated chromatin, a decline in monomethylation at lysine 4 of histone H3, and recruitment of RNA Pol II to IGF-I promoter 2. We conclude that GH actions induce rapid and dramatic changes in hepatic chromatin at the IGF-I locus and activate IGF-I gene transcription in the liver by distinct promoter-specific mechanisms: at promoter 1, GH causes RNA Pol II to be released from a previously recruited paused preinitiation complex, whereas at promoter 2, hormone treatment facilitates recruitment and then activation of RNA Pol II to initiate transcription.


2007 ◽  
Vol 28 (3) ◽  
pp. 1041-1046 ◽  
Author(s):  
Edwin R. Smith ◽  
Min Gyu Lee ◽  
Benjamin Winter ◽  
Nathan M. Droz ◽  
Joel C. Eissenberg ◽  
...  

ABSTRACT Histone H3 methylation at Lys27 (H3K27 methylation) is a hallmark of silent chromatin, while H3K4 methylation is associated with active chromatin regions. Here we report that a Drosophila JmjC family member, dUTX, specifically demethylates di- and trimethylated but not monomethylated H3K27. dUTX localization on chromatin correlates with the elongating form of RNA polymerase II (Pol II), and dUTX can associate with Pol II. Furthermore, heat shock induction results in the recruitment of dUTX to the hsp70 gene, like that of several other Pol II elongation factors. Our data indicate that dUTX is intimately associated with actively transcribed genes and may provide a paradigm for how H3K27 demethylation is required for the activation of preinitiated Pol II on transcriptionally poised genes.


2019 ◽  
Vol 116 (9) ◽  
pp. 3734-3739 ◽  
Author(s):  
Sarah E. Dremel ◽  
Neal A. DeLuca

In herpes simplex virus type 1 (HSV-1) infection, the coupling of genome replication and transcription regulation has been known for many years; however, the underlying mechanism has not been elucidated. We performed a comprehensive transcriptomic assessment and factor-binding analysis for Pol II, TBP, TAF1, and Sp1 to assess the effect genome replication has on viral transcription initiation and elongation. The onset of genome replication resulted in the binding of TBP, TAF1, and Pol II to previously silent late promoters. The viral transcription factor, ICP4, was continuously needed in addition to DNA replication for activation of late gene transcription initiation. Furthermore, late promoters contain a motif that closely matches the consensus initiator element (Inr), which robustly bound TAF1 postreplication. Continued DNA replication resulted in reduced binding of Sp1, TBP, and Pol II to early promoters. Therefore, the initiation of early gene transcription is attenuated following DNA replication. Herein, we propose a model for how viral DNA replication results in the differential utilization of cellular factors that function in transcription initiation, leading to the delineation of kinetic class in HSV-productive infection.


2011 ◽  
Vol 39 (6) ◽  
pp. 1705-1709 ◽  
Author(s):  
Erin M. Bank ◽  
Yosef Gruenbaum

In metazoan cells, the heterochromatin is generally localized at the nuclear periphery, whereas active genes are preferentially found in the nuclear interior. In the present paper, we review current evidence showing that components of the nuclear lamina interact directly with heterochromatin, which implicates the nuclear lamina in a mechanism of specific gene retention at the nuclear periphery and release to the nuclear interior upon gene activation. We also discuss recent data showing that mutations in lamin proteins affect gene positioning and expression, providing a potential mechanism for how these mutations lead to tissue-specific diseases.


1999 ◽  
Vol 10 (4) ◽  
pp. 1235-1245 ◽  
Author(s):  
Manfred Alsheimer ◽  
Elisabeth von Glasenapp ◽  
Robert Hock ◽  
Ricardo Benavente

The nucleus of spermatocytes provides during the first meiotic prophase an interesting model for investigating relationships of the nuclear envelope (NE) with components of the nuclear interior. During the pachytene stage, meiotic chromosomes are synapsed via synaptonemal complexes (SCs) and attached through both ends to the nuclear periphery. This association is dynamic because chromosomes move during the process of synapsis and desynapsis that takes place during meiotic prophase. The NE of spermatocytes possesses some peculiarities (e.g., lower stability than in somatic cells, expression of short meiosis-specific lamin isoforms called C2 and B3) that could be critically involved in this process. For better understanding of the association of chromosomes with the nuclear periphery, in the present study we have investigated the distribution of NE proteins in relation to SC attachment sites. A major outcome was the finding that lamin C2 is distributed in the form of discontinuous domains at the NE of spermatocytes and that SC attachment sites are embedded in these domains. Lamin C2 appears to form part of larger structures as suggested by cell fractionation experiments. According to these results, we propose that the C2-containing domains represent local reinforcements of the NE that are involved in the proper attachment of SCs.


2005 ◽  
Vol 25 (23) ◽  
pp. 10507-10515 ◽  
Author(s):  
Michelle L. Ebbs ◽  
Lisa Bartee ◽  
Judith Bender

ABSTRACT Transcribed inverted repeats are potent triggers for RNA interference and RNA-directed DNA methylation in plants through the production of double-stranded RNA (dsRNA). For example, a transcribed inverted repeat of endogenous genes in Arabidopsis thaliana, PAI1-PAI4, guides methylation of itself as well as two unlinked duplicated PAI genes, PAI2 and PAI3. In previous work, we found that mutations in the SUVH4/KYP histone H3 lysine 9 (H3 K9) methyltransferase cause a loss of DNA methylation on PAI2 and PAI3, but not on the inverted repeat. Here we use chromatin immunoprecipitation analysis to show that the transcribed inverted repeat carries H3 K9 methylation, which is maintained even in an suvh4 mutant. PAI1-PAI4 H3 K9 methylation and DNA methylation are also maintained in an suvh6 mutant, which is defective for a gene closely related to SUVH4. However, both epigenetic modifications are reduced at this locus in an suvh4 suvh6 double mutant. In contrast, SUVH6 does not play a significant role in maintenance of H3 K9 or DNA methylation on PAI2, transposon sequences, or centromere repeat sequences. Thus, SUVH6 is preferentially active at a dsRNA source locus versus targets for RNA-directed chromatin modifications.


2006 ◽  
Vol 26 (8) ◽  
pp. 3135-3148 ◽  
Author(s):  
Hongfang Qiu ◽  
Cuihua Hu ◽  
Chi-Ming Wong ◽  
Alan G. Hinnebusch

ABSTRACT The Paf1 complex (Paf1C) interacts with RNA polymerase II (Pol II) and promotes histone methylation of transcribed coding sequences, but the mechanism of Paf1C recruitment is unknown. We show that Paf1C is not recruited directly by the activator Gcn4p but is dependent on preinitiation complex assembly and Ser5 carboxy-terminal domain phosphorylation for optimal association with ARG1 coding sequences. Importantly, Spt4p is required for Paf1C occupancy at ARG1 (and other genes) and for Paf1C association with Ser5-phosphorylated Pol II in cell extracts, whereas Spt4p-Pol II association is independent of Paf1C. Since spt4Δ does not reduce levels of Pol II at ARG1, Ser5 phosphorylation, or Paf1C expression, it appears that Spt4p (or its partner in DSIF, Spt5p) provides a platform on Pol II for recruiting Paf1C following Ser5 phosphorylation and promoter clearance. spt4Δ reduces trimethylation of Lys4 on histone H3, demonstrating a new role for yeast DSIF in promoting a Paf1C-dependent function in elongation.


2007 ◽  
Vol 27 (13) ◽  
pp. 4891-4904 ◽  
Author(s):  
H. Karimi Kinyamu ◽  
Trevor K. Archer

ABSTRACT The 26S proteasome modulates steroid hormone receptor-dependent gene transcription at least in part by regulating turnover and recycling of receptor/transcriptional DNA complexes, thereby ensuring continued hormone response. For the glucocorticoid receptor (GR), inhibition of proteasome-mediated proteolysis or RNA interference-mediated depletion of specific proteasome subunits results in an increase in gene expression. To facilitate transcription, proteasome inhibition alters at least two features associated with modification of chromatin architecture and gene transcription. First, proteasome inhibition increases trimethyl histone H3K4 levels with a corresponding accumulation of this modification on GR-regulated promoters in vivo. Secondly, global levels of phosphorylated RNA polymerase II (Pol II) increase, together with hormone-dependent association of the phosphorylated Pol II, with the promoter and the body of the activated gene. We propose that apart from modulating receptor turnover, the proteasome directly influences both the transcription machinery and chromatin structure, factors integral to nuclear receptor-regulated gene transcription.


2005 ◽  
Vol 18 (6) ◽  
pp. 723-734 ◽  
Author(s):  
Antonin Morillon ◽  
Nickoletta Karabetsou ◽  
Anitha Nair ◽  
Jane Mellor

Endocrinology ◽  
2007 ◽  
Vol 148 (10) ◽  
pp. 4592-4600 ◽  
Author(s):  
A. K. Ho ◽  
D. M. Price ◽  
W. G. Dukewich ◽  
N. Steinberg ◽  
T. G. Arnason ◽  
...  

In this study we investigated the effect of histone acetylation on the transcription of adrenergic-induced genes in rat pinealocytes. We found that treatment of pinealocytes with trichostatin A (TSA), a histone deacetylase inhibitor, caused hyperacetylation of histone H3 (H3) Lys14 at nanomolar concentrations. Hyperacetylation of H3 was also observed after treatment with scriptaid, a structurally unrelated histone deacetylase inhibitor. The effects of TSA and scriptaid were inhibitory on the adrenergic induction of arylalkylamine-n-acetyltransferase (aa-nat) mRNA, protein, and enzyme activity, and on melatonin production. TSA at higher concentrations also inhibited the adrenergic induction of mapk phosphatase-1 (mkp-1) and inducible cAMP early repressor mRNAs. In contrast, the effect of TSA on the norepinephrine induction of the c-fos mRNA was stimulatory. Moreover, the effect of TSA on adrenergic-induced gene transcription was dependent on the time of its addition; its effect was only observed during the active phase of transcription. Chromatin immunoprecipitation with antibodies against acetylated Lys14 of H3 showed an increase in DNA recovery of the promoter regions of aa-nat, mkp-1, and c-fos after treatment with TSA. Together, our results demonstrate that histone acetylation differentially influences the transcription of adrenergic-induced genes, an enhancing effect for c-fos but inhibitory for aa-nat, mkp-1, and inducible cAMP early repressor. Moreover, both inhibitory and enhancing effects appear to be mediated through specific modification of promoter-bound histones during gene transcription.


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