scholarly journals BRD4 methylation by the methyltransferase SETD6 regulates selective transcription to control mRNA translation

2021 ◽  
Vol 7 (22) ◽  
pp. eabf5374
Author(s):  
Zlata Vershinin ◽  
Michal Feldman ◽  
Thilo Werner ◽  
Lital Estrella Weil ◽  
Margarita Kublanovsky ◽  
...  

The transcriptional coactivator BRD4 has a fundamental role in transcription regulation and thus became a promising epigenetic therapeutic candidate to target diverse pathologies. However, the regulation of BRD4 by posttranslational modifications has been largely unexplored. Here, we show that BRD4 is methylated on chromatin at lysine-99 by the protein lysine methyltransferase SETD6. BRD4 methylation negatively regulates the expression of genes that are involved in translation and inhibits total mRNA translation in cells. Mechanistically, we provide evidence that supports a model where BRD4 methylation by SETD6 does not have a direct role in the association with acetylated histone H4 at chromatin. However, this methylation specifically determines the recruitment of the transcription factor E2F1 to selected target genes that are involved in mRNA translation. Together, our findings reveal a previously unknown molecular mechanism for BRD4 methylation–dependent gene-specific targeting, which may serve as a new direction for the development of therapeutic applications.

Structure ◽  
2014 ◽  
Vol 22 (2) ◽  
pp. 353-360 ◽  
Author(s):  
Alexander N. Plotnikov ◽  
Shuai Yang ◽  
Thomas Jiachi Zhou ◽  
Elena Rusinova ◽  
Antonio Frasca ◽  
...  

2020 ◽  
Vol 295 (14) ◽  
pp. 4748-4759 ◽  
Author(s):  
Hang Gyeong Chin ◽  
Pierre-Olivier Esteve ◽  
Cristian Ruse ◽  
Jiyoung Lee ◽  
Scott E. Schaus ◽  
...  

Microtubules are cytoskeletal structures critical for mitosis, cell motility, and protein and organelle transport and are a validated target for anticancer drugs. However, how tubulins are regulated and recruited to support these distinct cellular processes is incompletely understood. Posttranslational modifications of tubulins are proposed to regulate microtubule function and dynamics. Although many of these modifications have been investigated, only one prior study reports tubulin methylation and an enzyme responsible for this methylation. Here we used in vitro radiolabeling, MS, and immunoblotting approaches to monitor protein methylation and immunoprecipitation, immunofluorescence, and pulldown approaches to measure protein–protein interactions. We demonstrate that N-lysine methyltransferase 5A (KMT5A or SET8/PR-Set7), which methylates lysine 20 in histone H4, bound α-tubulin and methylated it at a specific lysine residue, Lys311. Furthermore, late SV40 factor (LSF)/CP2, a known transcription factor, bound both α-tubulin and SET8 and enhanced SET8-mediated α-tubulin methylation in vitro. In addition, we found that the ability of LSF to facilitate this methylation is countered by factor quinolinone inhibitor 1 (FQI1), a specific small-molecule inhibitor of LSF. These findings suggest the general model that microtubule-associated proteins, including transcription factors, recruit or stimulate protein-modifying enzymes to target tubulins. Moreover, our results point to dual functions for SET8 and LSF not only in chromatin regulation but also in cytoskeletal modification.


2015 ◽  
Vol 35 (23) ◽  
pp. 3934-3944 ◽  
Author(s):  
Kayla A. Martin ◽  
Matteo Cesaroni ◽  
Michael F. Denny ◽  
Lena N. Lupey ◽  
Italo Tempera

Posttranslational modifications, such as poly(ADP-ribosyl)ation (PARylation), regulate chromatin-modifying enzymes, ultimately affecting gene expression. This study explores the role of poly(ADP-ribose) polymerase (PARP) on global gene expression in a lymphoblastoid B cell line. We found that inhibition of PARP catalytic activity with olaparib resulted in global gene deregulation, affecting approximately 11% of the genes expressed. Gene ontology analysis revealed that PARP could exert these effects through transcription factors and chromatin-remodeling enzymes, including the polycomb repressive complex 2 (PRC2) member EZH2. EZH2 mediates the trimethylation of histone H3 at lysine 27 (H3K27me3), a modification associated with chromatin compaction and gene silencing. Both pharmacological inhibition of PARP and knockdown of PARP1 induced the expression of EZH2, which resulted in increased global H3K27me3. Chromatin immunoprecipitation confirmed that PARP1 inhibition led to H3K27me3 deposition at EZH2 target genes, which resulted in gene silencing. Moreover, increased EZH2 expression is attributed to the loss of the occupancy of the transcription repressor E2F4 at the EZH2 promoter following PARP inhibition. Together, these data show that PARP plays an important role in global gene regulation and identifies for the first time a direct role of PARP1 in regulating the expression and function of EZH2.


2018 ◽  
Vol 39 (3) ◽  
Author(s):  
Suneer Verma ◽  
Paul De Jesus ◽  
Sumit K. Chanda ◽  
Inder M. Verma

ABSTRACT The nuclear factor kappa B (NF-κB) family of transcription factors plays a central role in coordinating the expression of genes that control inflammation, immune responses, cell proliferation, and a variety of other biological processes. In an attempt to identify novel regulators of this pathway, we performed whole-genome RNA interference (RNAi) screens in physiologically relevant human macrophages in response to lipopolysaccharide and tumor necrosis factor alpha (TNF-α). The top hit was SNW1, a splicing factor and transcriptional coactivator. SNW1 does not regulate the cytoplasmic components of the NF-κB pathway but complexes with the NF-κB heterodimer in the nucleus for transcriptional activation. We show that SNW1 detaches from its splicing complex (formed with SNRNP200 and SNRNP220) upon NF-κB activation and binds to NF-κB’s transcriptional elongation partner p-TEFb. We also show that SNW1 is indispensable for the transcriptional elongation of NF-κB target genes such as the interleukin 8 (IL-8) and TNF genes. SNW1 is a unique protein previously shown to be involved in both splicing and transcription, and in this case, its role involves binding to the NF-κB–p-TEFb complex to facilitate transcriptional elongation of some NF-κB target genes.


2021 ◽  
Author(s):  
Chun Yang ◽  
Stéphane Croteau ◽  
Pierre Hardy

Abstract Background HDAC9 (histone deacetylase 9) belongs to the class IIa family of histone deacetylases. This enzyme can shuttle freely between the nucleus and cytoplasm and promotes tissue-specific transcriptional regulation by interacting with histone and non-histone substrates. HDAC9 plays an essential role in diverse physiological processes including cardiac muscle development, bone formation, adipocyte differentiation and innate immunity. HDAC9 inhibition or activation is therefore a promising avenue for therapeutic intervention in several diseases. HDAC9 overexpression is also common in cancer cells, where HDAC9 alters the expression and activity of numerous relevant proteins involved in carcinogenesis. Conclusions This review summarizes the most recent discoveries regarding HDAC9 as a crucial regulator of specific physiological systems and, more importantly, highlights the diverse spectrum of HDAC9-mediated posttranslational modifications and their contributions to cancer pathogenesis. HDAC9 is a potential novel therapeutic target, and the restoration of aberrant expression patterns observed among HDAC9 target genes and their related signaling pathways may provide opportunities to the design of novel anticancer therapeutic strategies.


Oncogene ◽  
2021 ◽  
Author(s):  
Panagiotis Papoutsoglou ◽  
Dorival Mendes Rodrigues-Junior ◽  
Anita Morén ◽  
Andrew Bergman ◽  
Fredrik Pontén ◽  
...  

AbstractActivation of the transforming growth factor β (TGFβ) pathway modulates the expression of genes involved in cell growth arrest, motility, and embryogenesis. An expression screen for long noncoding RNAs indicated that TGFβ induced mir-100-let-7a-2-mir-125b-1 cluster host gene (MIR100HG) expression in diverse cancer types, thus confirming an earlier demonstration of TGFβ-mediated transcriptional induction of MIR100HG in pancreatic adenocarcinoma. MIR100HG depletion attenuated TGFβ signaling, expression of TGFβ-target genes, and TGFβ-mediated cell cycle arrest. Moreover, MIR100HG silencing inhibited both normal and cancer cell motility and enhanced the cytotoxicity of cytostatic drugs. MIR100HG overexpression had an inverse impact on TGFβ signaling responses. Screening for downstream effectors of MIR100HG identified the ligand TGFβ1. MIR100HG and TGFB1 mRNA formed ribonucleoprotein complexes with the RNA-binding protein HuR, promoting TGFβ1 cytokine secretion. In addition, TGFβ regulated let-7a-2–3p, miR-125b-5p, and miR-125b-1–3p expression, all encoded by MIR100HG intron-3. Certain intron-3 miRNAs may be involved in TGFβ/SMAD-mediated responses (let-7a-2–3p) and others (miR-100, miR-125b) in resistance to cytotoxic drugs mediated by MIR100HG. In support of a model whereby TGFβ induces MIR100HG, which then enhances TGFβ1 secretion, analysis of human carcinomas showed that MIR100HG expression correlated with expression of TGFB1 and its downstream extracellular target TGFBI. Thus, MIR100HG controls the magnitude of TGFβ signaling via TGFβ1 autoinduction and secretion in carcinomas.


2021 ◽  
Vol 11 (7) ◽  
pp. 889
Author(s):  
Anton D. Filev ◽  
Denis N. Silachev ◽  
Ivan A. Ryzhkov ◽  
Konstantin N. Lapin ◽  
Anastasiya S. Babkina ◽  
...  

The overactivation of inflammatory pathways and/or a deficiency of neuroplasticity may result in the delayed recovery of neural function in traumatic brain injury (TBI). A promising approach to protecting the brain tissue in TBI is xenon (Xe) treatment. However, xenon’s mechanisms of action remain poorly clarified. In this study, the early-onset expression of 91 target genes was investigated in the damaged and in the contralateral brain areas (sensorimotor cortex region) 6 and 24 h after injury in a TBI rat model. The expression of genes involved in inflammation, oxidation, antioxidation, neurogenesis and neuroplasticity, apoptosis, DNA repair, autophagy, and mitophagy was assessed. The animals inhaled a gas mixture containing xenon and oxygen (ϕXe = 70%; ϕO2 25–30% 60 min) 15–30 min after TBI. The data showed that, in the contralateral area, xenon treatment induced the expression of stress genes (Irf1, Hmox1, S100A8, and S100A9). In the damaged area, a trend towards lower expression of the inflammatory gene Irf1 was observed. Thus, our results suggest that xenon exerts a mild stressor effect in healthy brain tissue and has a tendency to decrease the inflammation following damage, which might contribute to reducing the damage and activating the early compensatory processes in the brain post-TBI.


2005 ◽  
Vol 187 (22) ◽  
pp. 7703-7715 ◽  
Author(s):  
Isabel Delany ◽  
Raffaele Ieva ◽  
Alice Soragni ◽  
Markus Hilleringmann ◽  
Rino Rappuoli ◽  
...  

ABSTRACT Two important metal-responsive regulators, NikR and Fur, are involved in nickel and iron homeostasis and controlling gene expression in Helicobacter pylori. To date, they have been implicated in the regulation of sets of overlapping genes. We have attempted here dissection of the molecular mechanisms involved in transcriptional regulation of the NikR and Fur proteins, and we investigated protein-promoter interactions of the regulators with known target genes. We show that H. pylori NikR is a tetrameric protein and, through DNase I footprinting analysis, we have identified operators for NikR to which it binds with different affinities in a metal-responsive way. Mapping of the NikR binding site upstream of the urease promoter established a direct role for NikR as a positive regulator of transcription and, through scanning mutagenesis of this binding site, we have determined two subsites that are important for the binding of the protein to its target sequence. Furthermore, by alignment of the operators for NikR, we have shown that the H. pylori protein recognizes a sequence that is distinct from its well-studied orthologue in Escherichia coli. Moreover, we show that NikR and Fur can bind independently at distinct operators and also compete for overlapping operators in some coregulated gene promoters, adding another dimension to the previous suggested link between iron and nickel regulation. Finally, the importance of an interconnection between metal-responsive gene networks for homeostasis is discussed.


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