scholarly journals H4R3 methylation facilitates β-globin transcription by regulating histone acetyltransferase binding and H3 acetylation

Blood ◽  
2010 ◽  
Vol 115 (10) ◽  
pp. 2028-2037 ◽  
Author(s):  
Xingguo Li ◽  
Xin Hu ◽  
Bhavita Patel ◽  
Zhuo Zhou ◽  
Shermi Liang ◽  
...  
Keyword(s):  
Histone Acetylation ◽  
Chromatin Structure ◽  
Globin Gene ◽  
Histone H3 ◽  
Arginine Methylation ◽  
Globin Genes ◽  
Erythroid Progenitor ◽  
Histone H3 Acetylation ◽  
H3 Acetylation

Abstract Histone modifications play an important role in the process of transcription. However, in contrast to lysine methylation, the role of arginine methylation in chromatin structure and transcription has been underexplored. The globin genes are regulated by a highly organized chromatin structure that juxtaposes the locus control region (LCR) with downstream globin genes. We report here that the targeted recruitment of asymmetric dimethyl H4R3 catalyzed by PRMT1 (protein arginine methyltransferase 1) facilitates histone H3 acetylation on Lys9/Lys14. Dimethyl H4R3 provides a binding surface for P300/CBP-associated factor (PCAF) and directly enhances histone H3 acetylation in vitro. We show that these active modifications are essential for efficient interactions between the LCR and the βmaj-promoter as well as transcription of the β-globin gene. Furthermore, knockdown (KD) of PRMT1 by RNA interference in erythroid progenitor cells prevents histone acetylation, enhancer and promoter interaction, and recruitment of transcription complexes to the active β-globin promoter. Reintroducing rat PRMT1 into the PRMT1 KD MEL cells rescues PRMT1 binding, β-globin transcription, and erythroid differentiation. Taken together, our data suggest that PRMT1-mediated dimethyl H4R3 facilitates histone acetylation and enhancer/promoter communications, which lead to the efficient recruitment of transcription preinitiation complexes to active promoters.

scholarly journals Interplay between Chromatin and trans-Acting Factors on the IME2 Promoter upon Induction of the Gene at the Onset of Meiosis

2006 ◽  
Vol 27 (4) ◽  
pp. 1254-1263 ◽  
Author(s):  
Tomomi Inai ◽  
Masashi Yukawa ◽  
Eiko Tsuchiya
Keyword(s):  
Histone Deacetylase ◽  
Chromatin Structure ◽  
Molecular Basis ◽  
Histone Acetyltransferase ◽  
Histone H3 ◽  
Repressive Chromatin ◽  
Tata Element ◽  
Histone H3 Acetylation ◽  
Low Levels ◽  
H3 Acetylation

ABSTRACT The IME2 gene is one of the key regulators of the initiation of meiosis in budding yeast. This gene is repressed during mitosis through the repressive chromatin structure at the promoter, which is maintained by the Rpd3-Sin3 histone deacetylase (HDAC) complex. IME2 expression in meiosis requires Gcn5/histone acetyltransferase, the transcriptional activator Ime1, and the chromatin remodeler RSC; however, the molecular basis of IME2 activation had not been previously defined. We found that, during mitotic growth, a nucleosome masked the TATA element of IME2, and this positioning depended on HDAC. This chromatin structure was remodeled at meiosis by RSC that was recruited to TATA by Ime1. Stable tethering of Ime1 to the promoter required the presence of Gcn5. Interestingly, Ime1 binding to the promoter was kept at low levels during the very early stages in meiosis, even when the levels of Ime1 and histone H3 acetylation at the promoter were at their highest, making a 4- to 6-h delay of the IME2 expression from that of IME1. HDAC was continuously present at the promoter regardless of the transcriptional condition of IME2, and deletion of RPD3 allowed the IME2 expression shortly after the expression of IME1, suggesting that HDAC plays a role in regulating the timing of IME2 expression.

The G9A Histone Methyltransferase BIX-01294 Reactivates ε-Globin Expression and Blocks Erythroid Differentiation in Primary Baboon Erythroid Progenitor Cell Cultures

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 129-129 ◽  
Author(s):  
Virryan Banzon ◽  
Vinzon Ibanez ◽  
Kestis Vaitkus ◽  
Tatiana Kousnetzova ◽  
Joseph Desimone ◽  
...  
Keyword(s):  
Gene Silencing ◽  
Cell Cultures ◽  
Progenitor Cell ◽  
Globin Gene ◽  
Histone H3 ◽  
Erythroid Differentiation ◽  
Globin Genes ◽  
Erythroid Cells ◽  
Erythroid Progenitor ◽  
Erythroid Progenitor Cell

Abstract The development of new therapies to increase fetal hemoglobin (HbF) levels in patients with sickle cell disease and β-thalassemia depends on an increased understanding of the mechanism responsible for the developmental regulation of globin gene expression. A role for epigenetic modifications in the mechanism of of globin gene regulation is suggested by the presence of high levels of DNA methylation near the 5’ regions of developmentally silenced ε- and γ-globin genes and the ability of pharmacological inhibitors of DNA methyltransferase (DNMTase) to reactivate ε- and γ-globin expression in adults. Whether additional epigenetic modifications associated with gene silencing and DNA methylation, such as histone H3 (lys9) dimethylation, are also involved is unknown. To investigate the hypothesis that histone H3 (lys9) dimethylation may function in the mechanism of developmental globin gene silencing, chromatin immunopreciptation assays were performed to determine the distribution of histone H3 (lys9) dimethyl and histone H3 (lys9) acetyl throughout the β-globin gene complex in purified primary baboon bone marrow (BM) erythroid cells from phlebotomized baboons expressing low levels (5–10%) of HbF and purified erythroid cells from erythroid progenitor cell cultures expressing high levels of HbF (30–50%). In BM erythroid cells, the level of histone H3 (lys9) acetyl associated with the β-globin gene was 10–20 fold higher than with the ε- and γ-globin genes, while the level of histone H3 (lys9) dimethyl associated with the ε- and γ-globin genes was 2–4 fold higher than with the β-globin gene. In erythroid cells from day 12 erythroid progenitor cell cultures, the level of histone H3 (lys9) acetyl associated with the highly expressed γ- and β-globin genes was 10–20 fold higher than with the silent ε-globin gene, while the level of histone H3 (lys9) dimethyl associated with the ε-globin gene was 2–4 fold higher than with the γ- and β-globin genes. Therefore a reciprocal relationship was observed between levels of histone H3 (lys9) acetylation and dimethylation associated with active and inactive globin genes. Experiments were performed to further investigate the role of histone H3 (lys9) dimethyl in ε-globin gene silencing by determining the effect of the G9A histone methyltransferase inhibitor BIX-01294 on ε-globin expression. Erythroid progenitor cell cultures derived from CD34+ BM cells of three individual baboons were treated with the varying doses of the DNMTase inhibitor decitabine (0.125–1.0μM), and BIX-01294 (1.25–5μM), alone and in combination. Changes in ε- globin were assessed by real time PCR using the ΔΔCT method with α-globin as the standard. Decitabine (0.5μM) increased ε-globin 25.8±7.7 fold while BIX-01294 (2.5μM) increased ε-globin 3.09±1.16 fold. Decitabine (1μM) and BIX-01294 (2.5μM) in combination increased ε-globin 55.7±24.9 fold. BIX-01294 enhanced ε-globin expression approximately twofold at all decitabine doses ranging from 0.125–1.0μM (mean increase=103± 44.7%). BIX-01294 also blocked terminal erythroid differentiation and allowed expansion of more primitive cells as evidenced by the presence of a large population of basophilic erythroblasts at late stages of culture (day 14). These results demonstrate that BIX-01294 reactivates expression of the silenced ε-globin gene and that synergistic reactivation can be achieved using combinations of BIX-01294 and decitabine. While these results are consistent with the hypothesis that epigenetic modifications are important in the mechanism of developmental globin gene silencing, the observation that BIX-01294 blocks erythroid differentiation suggests the possible involvement of a reprogramming mechanism.

Differential histone acetylation in the Amygdala leads to fear memory consolidation and extinction

2015 ◽  
Vol 1 (1) ◽  
Author(s):  
Vandana Ranjan ◽  
Sanjay Singh ◽  
Sarfraj Ahmad Siddiqui ◽  
M Y Khan ◽  
Anand Prakash
Keyword(s):  
Histone Acetylation ◽  
Memory Consolidation ◽  
Histone H3 ◽  
Fear Memory ◽  
Memory Formation ◽  
Acetylation Level ◽  
Creb Activation ◽  
Conditioning Model ◽  
Histone H3 Acetylation ◽  
H3 Acetylation

<p>In the present study, a fear-conditioning model in rats was used to gauge the changes in the histone acetylation level in the<br />different nuclei of amygdala during fear memory consolidation and its extinction. It was found by immunohistochemical<br />examination of Amygdala that during the fear memory consolidation histone H3 acetylation level was significantly<br />increased in the Central amygdala (CeA), the output of the fear circuitry, as compared to the unconditioned group and<br />subsequently, when this fear memory was extinguished during fear extinction, the histone H3 acetylation levels decreased<br />significantly as compared to the conditioned group. However, in another nuclei of the amygdala, the intercalated cells<br />(ITCs) the Acetyl H3 levels increased during extinction and but not in the conditioned group as compared to the<br />unconditioned group. The p-ERK and p-CREB levels also significantly varied in the different nuclei of amygdala<br />between the two groups and showed correlation with the Histone acetylation changes observed in these groups. In<br />conclusion the present study points out that the memory formation, during fear memory consolidation and its extinction,<br />may be dependent on differential neuronal activity under epigenetic control through acetylation at k-9 residue of histone<br />H3, in different regions of the amygdala as evident by the p-ERK and p-CREB activation, which are the markers for<br />activity of neurons and memory formation.</p>

scholarly journals The Carboxyl Terminus of Rtt109 Functions in Chaperone Control of Histone Acetylation

2013 ◽  
Vol 12 (5) ◽  
pp. 654-664 ◽  
Author(s):  
Ernest Radovani ◽  
Matthew Cadorin ◽  
Tahireh Shams ◽  
Suzan El-Rass ◽  
Abdel R. Karsou ◽  
...  
Keyword(s):  
Histone Acetyltransferase ◽  
Histone H3 ◽  
Chromatin Assembly ◽  
Carboxyl Terminus ◽  
Histone Chaperones ◽  
Content Type ◽  
Histone H3 Acetylation ◽  
H3 Acetylation

ABSTRACT Rtt109 is a fungal histone acetyltransferase (HAT) that catalyzes histone H3 acetylation functionally associated with chromatin assembly. Rtt109-mediated H3 acetylation involves two histone chaperones, Asf1 and Vps75. In vivo , Rtt109 requires both chaperones for histone H3 lysine 9 acetylation (H3K9ac) but only Asf1 for full H3K56ac. In vitro , Rtt109-Vps75 catalyzes both H3K9ac and H3K56ac, whereas Rtt109-Asf1 catalyzes only H3K56ac. In this study, we extend the in vitro chaperone-associated substrate specificity of Rtt109 by showing that it acetylates vertebrate linker histone in the presence of Vps75 but not Asf1. In addition, we demonstrate that in Saccharomyces cerevisiae a short basic sequence at the carboxyl terminus of Rtt109 (Rtt109C) is required for H3K9ac in vivo . Furthermore, through in vitro and in vivo studies, we demonstrate that Rtt109C is required for optimal H3K56ac by the HAT in the presence of full-length Asf1. When Rtt109C is absent, Vps75 becomes important for H3K56ac by Rtt109 in vivo . In addition, we show that lysine 290 (K290) in Rtt109 is required in vivo for Vps75 to enhance the activity of the HAT. This is the first in vivo evidence for a role for Vps75 in H3K56ac. Taken together, our results contribute to a better understanding of chaperone control of Rtt109-mediated H3 acetylation.

scholarly journals Drosophila Ada2b Is Required for Viability and Normal Histone H3 Acetylation

2004 ◽  
Vol 24 (18) ◽  
pp. 8080-8089 ◽  
Author(s):  
Dai Qi ◽  
Jan Larsson ◽  
Mattias Mannervik
Keyword(s):  
Gene Expression ◽  
Transcriptional Activation ◽  
Protein Complexes ◽  
P53 Protein ◽  
Polytene Chromosomes ◽  
Histone H3 ◽  
Saga Complex ◽  
Histone H3 Acetylation ◽  
H3 Acetylation

ABSTRACT Regulation of chromatin through histone acetylation is an important step in gene expression. The Gcn5 histone acetyltransferase is part of protein complexes, e.g., the SAGA complex, that interact with transcriptional activators, targeting the enzyme to specific promoters and assisting in recruitment of the basal RNA polymerase transcription machinery. The Ada2 protein directly binds to Gcn5 and stimulates its catalytic activity. Drosophila contains two Ada2 proteins, Drosophila Ada2a (dAda2a) and dAda2b. We have generated flies that lack dAda2b, which is part of a Drosophila SAGA-like complex. dAda2b is required for viability in Drosophila, and its deletion causes a reduction in histone H3 acetylation. A global hypoacetylation of chromatin was detected on polytene chromosomes in dAda2b mutants. This indicates that the dGcn5-dAda2b complex could have functions in addition to assisting in transcriptional activation through gene-specific acetylation. Although the Drosophila p53 protein was previously shown to interact with the SAGA-like complex in vitro, we find that p53 induction of reaper gene expression occurs normally in dAda2b mutants. Moreover, dAda2b mutant animals show excessive p53-dependent apoptosis in response to gamma radiation. Based on this result, we speculate that dAda2b may be necessary for efficient DNA repair or generation of a DNA damage signal. This could be an evolutionarily conserved function, since a yeast ada2 mutant is also sensitive to a genotoxic agent.

scholarly journals Role of the CBP catalytic core in intramolecular SUMOylation and control of histone H3 acetylation

2017 ◽  
Vol 114 (27) ◽  
pp. E5335-E5342 ◽  
Author(s):  
Sangho Park ◽  
Robyn L. Stanfield ◽  
Maria A. Martinez-Yamout ◽  
H. Jane Dyson ◽  
Ian A. Wilson ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Critical Role ◽  
Histone H3 ◽  
Negative Regulator ◽  
Creb Binding Protein ◽  
Catalytic Core ◽  
Intrinsically Disordered ◽  
Histone H3 Acetylation ◽  
H3 Acetylation

The histone acetyl transferases CREB-binding protein (CBP) and its paralog p300 play a critical role in numerous cellular processes. Dysregulation of their catalytic activity is associated with several human diseases. Previous work has elucidated the regulatory mechanisms of p300 acetyltransferase activity, but it is not known whether CBP activity is controlled similarly. Here, we present the crystal structure of the CBP catalytic core encompassing the bromodomain (BRD), CH2 (comprising PHD and RING), HAT, and ZZ domains at 2.4-Å resolution. The BRD, PHD, and HAT domains form an integral structural unit to which the RING and ZZ domains are flexibly attached. The structure of the apo-CBP HAT domain is similar to that of acyl-CoA–bound p300 HAT complexes and shows that the acetyl-CoA binding site is stably formed in the absence of cofactor. The BRD, PHD, and ZZ domains interact with small ubiquitin-like modifier 1 (SUMO-1) and Ubc9, and function as an intramolecular E3 ligase for SUMOylation of the cell cycle regulatory domain 1 (CRD1) of CBP, which is located adjacent to the BRD. In vitro HAT assays suggest that the RING domain, the autoregulatory loop (AL) within the HAT domain, and the ZZ domain do not directly influence catalytic activity, whereas the BRD is essential for histone H3 acetylation in nucleosomal substrates. Several lysine residues in the intrinsically disordered AL are autoacetylated by the HAT domain. Upon autoacetylation, acetyl-K1596 (Ac-K1596) binds intramolecularly to the BRD, competing with histones for binding to the BRD and acting as a negative regulator that inhibits histone H3 acetylation.

scholarly journals The Essential Gene wda Encodes a WD40 Repeat Subunit of Drosophila SAGA Required for Histone H3 Acetylation

2006 ◽  
Vol 26 (19) ◽  
pp. 7178-7189 ◽  
Author(s):  
Sebastián Guelman ◽  
Tamaki Suganuma ◽  
Laurence Florens ◽  
Vikki Weake ◽  
Selene K. Swanson ◽  
...  
Keyword(s):  
Histone Acetylation ◽  
Essential Gene ◽  
Histone H3 ◽  
The Novel ◽  
Critical Function ◽  
High Molecular Weight Complex ◽  
Proteomic Approach ◽  
Histone H3 Acetylation ◽  
H3 Acetylation ◽  
Novel Protein

ABSTRACT Histone acetylation provides a switch between transcriptionally repressive and permissive chromatin. By regulating the chromatin structure at specific promoters, histone acetyltransferases (HATs) carry out important functions during differentiation and development of higher eukaryotes. HAT complexes are present in organisms as diverse as Saccharomyces cerevisiae, humans, and flies. For example, the well-studied yeast SAGA is related to three mammalian complexes. We previously identified Drosophila melanogaster orthologues of yeast SAGA components Ada2, Ada3, Spt3, and Tra1 and demonstrated that they associate with dGcn5 in a high-molecular-weight complex. To better understand the function of Drosophila SAGA (dSAGA), we sought to affinity purify and characterize this complex in more detail. A proteomic approach led to the identification of an orthologue of the yeast protein Ada1 and the novel protein encoded by CG4448, referred to as WDA (will decrease acetylation). Embryos lacking both alleles of the wda gene exhibited reduced levels of histone H3 acetylation and could not develop into adult flies. Our results point to a critical function of dSAGA and histone acetylation during Drosophila development.

Expression of γ-Globin Is Reactivated by a Novel Mechanism in Baboon CD34+ Erythroid Progenitor Cell Cultures.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 1768-1768
Author(s):  
Donald Lavelle ◽  
Janet Chin ◽  
Mahipal Singh ◽  
Kestis Vaitkus ◽  
Virryan Banzon ◽  
...  
Keyword(s):  
Cell Cultures ◽  
Progenitor Cell ◽  
Globin Gene ◽  
Histone H3 ◽  
Globin Genes ◽  
Erythroid Cells ◽  
Gene Methylation ◽  
Erythroid Progenitor ◽  
Erythroid Progenitor Cell ◽  
Low Levels

Abstract Elevated levels of fetal hemoglobin (HbF) reduce the symptoms of sickle cell disease and increase the life span of patients. Future pharmacologic therapies to increase HbF will depend on increased knowledge of the mechanism(s) regulating γ-globin gene expression. To investigate the relationship between DNA methylation, chromatin structure, and γ-globin gene regulation, DNA methylation of 5 CpG sites within γ-globin gene promoter, levels of acetyl-histone H3 and H4 and histone H3 lys4 trimethyl throughout the β-globin gene complex, and the pattern of γ-globin polypeptide chain synthesis were analyzed in primary baboon fetal liver (FL) erythroid cells, primary baboon bone marrow (ABM) erythroid cells from phlebotomized adults expressing low levels of HbF, ABM erythroid cells from adults expressing high levels of HbF following treatment in vivo with the DNA demethylating drug decitabine, and erythroid cells expressing high levels of HbF generated from CD34+ baboon BM erythroid progenitors in a liquid culture system. High levels of histone acetylation were associated with the ε- and γ-globin genes and low levels with the β-globin gene in FL erythroid cells while in ABM erythroid cells expressing low levels of HbF (6.69±1.93%) high levels were associated with the β-globin gene and low levels with the γ-globin gene. Histone H3 lys 4 trimethyl was enriched near the γ-globin gene in FL and the β-globin gene in ABM. The γ-globin gene was not methylated in FL. The level of methylation was similar in bled (75.1±8.26%) and normal (82.1±7.51%) ABM erythroid cells. The ratio of expression of 5′ Iγ- and 3′ Vγ-globin genes in the fetus (1.85) differed from bled adults (0.65). Expression of γ-globin was reactivated to similar levels in decitabine-treated baboons (51.5±4.50%) and in erythroid progenitor cell cultures (45.3±12.1%; d14). The Iγ- and Vγ-globin chains were expressed at the characteristic fetal ratio in erythroid progenitor cell cultures (1.76±0.21), but not in decitabine-treated baboons (0.76±0.32). Distribution of histone acetylation and histone H3 lys4 trimethyl was nearly identical in erythroid cells expressing high levels of HbF from decitabine-treated animals and from erythroid progenitor cultures and was characterized by high levels of histone H3 lys4 trimethyl associated with both the active γ- and β-globin genes and enrichment of histone H3 and H4 acetylation near the ε-, γ-, and β-globin genes. HbF reactivation in decitabine-treated baboons was associated with a reduction in the level of γ-globin gene methylation (33.5±9.43% dmC). Surprisingly, the level of γ-globin gene methylation in erythroid cells purified from erythroid progenitor cell cultures (79.5±9.80% dmC; d11) synthesizing high levels of γ-globin was not significantly different than in ABM erythroid cells expressing &lt;2% HbF. These results demonstrate that reactivation of γ-globin expression in erythroid progenitor cell cultures is uniquely characterized by the Iγ/Vγ-globin chain ratio of fetal development. In contrast to the absence of γ-globin gene methylation in FL and reduced levels associated with reactivation of HbF following decitabine treatment, the level of γ-globin gene methylation in erythroid progenitor cell cultures was the same as in ABM. Our data strongly suggests that reactivation of γ-globin gene expression in erythroid progenitor cell cultures is achieved through a novel mechanism not dependent on loss of DNA methylation.

Histone H3 acetylation of StAR and decrease in DAX-1 is involved in the luteinization of bovine granulosa cells during in vitro culture

2009 ◽  
Vol 328 (1-2) ◽  
pp. 41-47 ◽  
Author(s):  
Takashi Shimizu ◽  
Natsuko Sudo ◽  
Hiromichi Yamashita ◽  
Chiaki Murayama ◽  
Hitoshi Miyazaki ◽  
...  
Keyword(s):  
In Vitro Culture ◽  
Granulosa Cells ◽  
Histone H3 ◽  
Histone H3 Acetylation ◽  
H3 Acetylation

scholarly journals Cross-talk between Histone Modifications in Response to Histone Deacetylase Inhibitors

2006 ◽  
Vol 282 (7) ◽  
pp. 4408-4416 ◽  
Author(s):  
Karl P. Nightingale ◽  
Susanne Gendreizig ◽  
Darren A. White ◽  
Charlotte Bradbury ◽  
Florian Hollfelder ◽  
...  
Keyword(s):  
Histone Deacetylase ◽  
Histone Modifications ◽  
Histone Deacetylase Inhibitors ◽  
Gene Activation ◽  
Histone H3 ◽  
H3k4 Methylation ◽  
Histone H3 Acetylation ◽  
H3 Acetylation

Histones are subject to a wide variety of post-translational modifications that play a central role in gene activation and silencing. We have used histone modification-specific antibodies to demonstrate that two histone modifications involved in gene activation, histone H3 acetylation and H3 lysine 4 methylation, are functionally linked. This interaction, in which the extent of histone H3 acetylation determines both the abundance and the “degree” of H3K4 methylation, plays a major role in the epigenetic response to histone deacetylase inhibitors. A combination of in vivo knockdown experiments and in vitro methyltransferase assays shows that the abundance of H3K4 methylation is regulated by the activities of two opposing enzyme activities, the methyltransferase MLL4, which is stimulated by acetylated substrates, and a novel and as yet unidentified H3K4me3 demethylase.

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