scholarly journals Selective Interactions between Vertebrate Polycomb Homologs and the SUV39H1 Histone Lysine Methyltransferase Suggest that Histone H3-K9 Methylation Contributes to Chromosomal Targeting of Polycomb Group Proteins

2002 ◽  
Vol 22 (15) ◽  
pp. 5539-5553 ◽  
Author(s):  
Richard G. A. B. Sewalt ◽  
Monika Lachner ◽  
Mark Vargas ◽  
Karien M. Hamer ◽  
Jan L. den Blaauwen ◽  
...  
Keyword(s):  
Histone H3 ◽  
Histone Deacetylation ◽  
Polycomb Group ◽  
Gene Activity ◽  
Chromosome 1 ◽  
Histone Lysine ◽  
Histone Lysine Methyltransferase ◽  
Lysine Methyltransferase

ABSTRACT Polycomb group (PcG) proteins form multimeric chromatin-associated protein complexes that are involved in heritable repression of gene activity. Two distinct human PcG complexes have been characterized. The EED/EZH2 PcG complex utilizes histone deacetylation to repress gene activity. The HPC/HPH PcG complex contains the HPH, RING1, BMI1, and HPC proteins. Here we show that vertebrate Polycomb homologs HPC2 and XPc2, but not M33/MPc1, interact with the histone lysine methyltransferase (HMTase) SUV39H1 both in vitro and in vivo. We further find that overexpression of SUV39H1 induces selective nuclear relocalization of HPC/HPH PcG proteins but not of the EED/EZH2 PcG proteins. This SUV39H1-dependent relocalization concentrates the HPC/HPH PcG proteins to the large pericentromeric heterochromatin domains (1q12) on human chromosome 1. Within these PcG domains we observe increased H3-K9 methylation. Finally, we show that H3-K9 HMTase activity is associated with endogenous HPC2. Our findings suggest a role for the SUV39H1 HMTase and histone H3-K9 methylation in the targeting of human HPC/HPH PcG proteins to modified chromatin structures.

scholarly journals Protein lysine 43 methylation by EZH1 promotes AML1-ETO transcriptional repression in leukemia

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Liping Dou ◽  
Fei Yan ◽  
Jiuxia Pang ◽  
Dehua Zheng ◽  
Dandan Li ◽  
...  
Keyword(s):  
Dna Sequences ◽  
Transcriptional Repression ◽  
Lysine Methylation ◽  
Post Translational Modification ◽  
Histone Lysine Methylation ◽  
Histone Lysine ◽  
Histone Lysine Methyltransferase ◽  
Lysine Methyltransferase

Abstract The oncogenic fusion protein AML1-ETO retains the ability of AML1 to interact with the enhancer core DNA sequences, but blocks AML1-dependent transcription. Previous studies have shown that post-translational modification of AML1-ETO may play a role in its regulation. Here we report that AML1-ETO-positive patients, with high histone lysine methyltransferase Enhancer of zeste homolog 1 (EZH1) expression, show a worse overall survival than those with lower EZH1 expression. EZH1 knockdown impairs survival and proliferation of AML1-ETO-expressing cells in vitro and in vivo. We find that EZH1 WD domain binds to the AML1-ETO NHR1 domain and methylates AML1-ETO at lysine 43 (Lys43). This requires the EZH1 SET domain, which augments AML1-ETO-dependent repression of tumor suppressor genes. Loss of Lys43 methylation by point mutation or domain deletion impairs AML1-ETO-repressive activity. These findings highlight the role of EZH1 in non-histone lysine methylation, indicating that cooperation between AML1-ETO and EZH1 and AML1-ETO site-specific lysine methylation promote AML1-ETO transcriptional repression in leukemia.

Prenatal nicotine exposure leads to decreased histone H3 lysine 9 (H3K9) methylation and increased p66shc expression in the neonatal pancreas

2021 ◽  
pp. 1-5
Author(s):  
Sergio Raez-Villanueva ◽  
Amrita Debnath ◽  
Daniel B. Hardy ◽  
Alison C. Holloway
Keyword(s):  
Pancreatic Beta Cells ◽  
Histone H3 ◽  
Adverse Outcomes ◽  
Beta Cell Apoptosis ◽  
Nicotine Exposure ◽  
Nicotine Treatment ◽  
Histone Lysine ◽  
Histone Lysine Methyltransferase ◽  
Lysine Methyltransferase ◽  
Prenatal Nicotine

Abstract Prenatal exposure to nicotine, tobacco’s major addictive constituent, has been shown to reduce birth weight and increases apoptosis, oxidative stress, and mitochondrial dysfunction in the postnatal pancreas. Given that upregulated levels of the pro-oxidative adapter protein p66shc is observed in growth-restricted offspring and is linked to beta-cell apoptosis, the goal of this study was to investigate whether alterations in p66shc expression underlie the pancreatic deficits in nicotine-exposed offspring. Maternal administration of nicotine in rats increased p66shc expression in the neonatal pancreas. Similarly, nicotine treatment augmented p66shc expression in INS-1E pancreatic beta cells. Increased p66shc expression was also associated with decreased histone H3 lysine 9 methylation. Finally, nicotine increased the expression of Kdm4c, a key histone lysine demethylase, and decreased Suv39h1, a critical histone lysine methyltransferase. Collectively, these results suggest that upregulation of p66shc through posttranslational histone modifications may underlie the reported adverse outcomes of nicotine exposure on pancreatic function.

scholarly journals Deficiency of G9a Inhibits Cell Proliferation and Activates Autophagy via Transcriptionally Regulating c-Myc Expression in Glioblastoma

2020 ◽  
Vol 8 ◽  
Author(s):  
Xiao Xue Ke ◽  
Rui Zhang ◽  
Xi Zhong ◽  
Lei Zhang ◽  
Hongjuan Cui
Keyword(s):  
Cell Proliferation ◽  
Cyclin B1 ◽  
Luciferase Reporter ◽  
Cycle Arrest ◽  
Histone Lysine Methyltransferase ◽  
Lysine Methyltransferase ◽  
A Cell ◽  
Cell Proliferation Control

Glioblastoma is an aggressive and difficult to treat cancer. Recent data have emerged implicating that histone modification level may play a crucial role in glioma genesis. The histone lysine methyltransferase G9a is mainly responsible for the mono- and di-methylation of histone H3 lysine 9 (H3K9), whose overexpression is associated with a more aggressive phenotype in cancer. However, the detailed correlations between G9a and glioblastoma genesis remain to be further elucidated. Here, we show that G9a is essential for glioblastoma carcinogenesis and reveal a probable mechanism of it in cell proliferation control. We found that G9a was highly expressed in glioblastoma cells, and knockdown or inhibition of G9a significantly repressed cell proliferation and tumorigenesis ability both in vitro and in vivo. Besides, knockdown or inhibition of G9a led to a cell cycle arrest in G2 phase, as well as decreased the expression of CDK1, CDK2, Cyclin A2, and Cyclin B1, while it induced the activation of autophagy. Further investigation showed that G9a deficiency induced cell proliferation suppression, and activation of autophagy was rescued by overexpression of the full-length c-Myc. Chromatin immunoprecipitation (ChIP) assay showed that G9a was enriched on the −2267 to −1949 region of the c-Myc promoter in LN-229 cells and the −1949 to −1630 region of the c-Myc promoter in U-87 MG cells. Dual-luciferase reporter assay showed that c-Myc promoter activity was significantly reduced after knockdown or inhibition of G9a. Our study shows that G9a controls glioblastoma cell proliferation by transcriptionally modulating oncogene c-Myc and provides insight into the capabilities of G9a working as a potential therapeutic target in glioblastoma.

scholarly journals SETD4 Regulates Cell Quiescence and Catalyzes the Trimethylation of H4K20 during Diapause Formation in Artemia

2016 ◽  
Vol 37 (7) ◽  
Author(s):  
Li Dai ◽  
Sen Ye ◽  
Hua-Wei Li ◽  
Dian-Fu Chen ◽  
Hong-Liang Wang ◽  
...  
Keyword(s):  
Quiescent State ◽  
Degenerative Diseases ◽  
Set Domain ◽  
Content Type ◽  
Histone Lysine ◽  
Histone Lysine Methyltransferase ◽  
Cell Life ◽  
Cell Quiescence ◽  
Lysine Methyltransferase

ABSTRACT As a prominent characteristic of cell life, the regulation of cell quiescence is important for proper development, regeneration, and stress resistance and may play a role in certain degenerative diseases. However, the mechanism underlying quiescence remains largely unknown. Encysted embryos of Artemia are useful for studying the regulation of this state because they remain quiescent for prolonged periods during diapause, a state of obligate dormancy. In the present study, SET domain-containing protein 4, a histone lysine methyltransferase from Artemia, was identified, characterized, and named Ar-SETD4. We found that Ar-SETD4 was expressed abundantly in Artemia diapause embryos, in which cells were in a quiescent state. Meanwhile, trimethylated histone H4K20 (H4K20me3) was enriched in diapause embryos. The knockdown of Ar-SETD4 reduced the level of H4K20me3 significantly and prevented the formation of diapause embryos in which neither the cell cycle nor embryogenesis ceased. The catalytic activity of Ar-SETD4 on H4K20me3 was confirmed by an in vitro histone methyltransferase (HMT) assay and overexpression in cell lines. This study provides insights into the function of SETD4 and the mechanism of cell quiescence regulation.

scholarly journals Involvement of Histone Lysine Methylation in p21 Gene Expression in Rat KidneyIn Vivoand Rat Mesangial CellsIn Vitrounder Diabetic Conditions

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Xiangjun Li ◽  
Chaoyuan Li ◽  
Xiaoxia Li ◽  
Peihe Cui ◽  
Qifeng Li ◽  
...  
Keyword(s):  
Gene Expression ◽  
Molecular Mechanisms ◽  
Mesangial Cells ◽  
Histone H3 ◽  
Diabetic Rats ◽  
Lysine Methylation ◽  
Histone Lysine Methylation ◽  
Histone Lysine

Diabetic nephropathy (DN), a common complication associated with type 1 and type 2 diabetes mellitus (DM), characterized by glomerular mesangial expansion, inflammation, accumulation of extracellular matrix (ECM) protein, and hypertrophy, is the major cause of end-stage renal disease (ESRD). Increasing evidence suggested that p21-dependent glomerular and mesangial cell (MC) hypertrophy play key roles in the pathogenesis of DN. Recently, posttranscriptional modifications (PTMs) have uncovered novel molecular mechanisms involved in DN. However, precise regulatory mechanism of histone lysine methylation (HKme) mediating p21 related hypertrophy associated with DN is not clear. We evaluated the roles of HKme and histone methyltransferase (HMT) SET7/9 in p21 gene expression in glomeruli of diabetic rats and in high glucose- (HG-) treated rat mesangial cells (RMCs). p21 gene expression was upregulated in diabetic rats glomeruli; chromatin immunoprecipitation (ChIP) assays showed decreased histone H3-lysine9-dimethylation (H3K9me2) accompanied with enhanced histone H3-lysine4-methylation (H3K4me1/3) and SET7/9 occupancies at the p21 promoter. HG-treated RMCs exhibited increased p21 mRNA, H3K4me level, SET7/9 recruitment, and inverse H3K9me, which were reversed by TGF-β1 antibody. These data uncovered key roles of H3Kme and SET7/9 responsible for p21 gene expressionin vivoandin vitrounder diabetic conditions and confirmed preventive effect of TGF-β1 antibody on DN.

382 The Polycomb Histone Lysine Methyltransferase Ezh2 Reversibly Regulates the Fate of Interstitial Cells of Cajal (ICC) In Vivo

2015 ◽  
Vol 148 (4) ◽  
pp. S-79
Author(s):  
Sabriya A. Syed ◽  
Gabriella B. Gajdos ◽  
Srdjan Milosavljevic ◽  
Yujiro Hayashi ◽  
Raul A. Urrutia Sabine Klein ◽  
...  
Keyword(s):  
Interstitial Cells Of Cajal ◽  
Interstitial Cells ◽  
Histone Lysine ◽  
Histone Lysine Methyltransferase ◽  
Lysine Methyltransferase ◽  
Cells Of Cajal

scholarly journals Evolutionarily ancient BAH-PHD protein mediates Polycomb silencing

2019 ◽  
Author(s):  
Elizabeth T. Wiles ◽  
Kevin J. McNaught ◽  
Saumya M. De Silva ◽  
Gurmeet Kaur ◽  
Jeanne M. Selker ◽  
...  
Keyword(s):  
Neurospora Crassa ◽  
Filamentous Fungus ◽  
Phylogenetic Analyses ◽  
Chromatin Modification ◽  
Histone H3 ◽  
Polycomb Group ◽  
H3k27 Methylation ◽  
Polycomb Repression

AbstractMethylation of histone H3 lysine 27 (H3K27) is widely recognized as a transcriptionally repressive chromatin modification but the mechanism of repression remains unclear. We devised and implemented a forward genetic scheme to identify factors required for H3K27 methylation-mediated silencing in the filamentous fungus Neurospora crassa and identified a bromo-adjacent homology (BAH)-plant homeodomain (PHD)-containing protein, EPR-1 (Effector of Polycomb Repression 1; NCU07505). EPR-1 associates with H3K27 methylation in vivo and in vitro, and loss of EPR-1 de-represses H3K27-methylated genes without loss of H3K27 methylation. EPR-1 is not fungal-specific; orthologs of EPR-1 are present in a diverse array of eukaryotic lineages, suggesting an ancestral EPR-1 was a component of a primitive Polycomb repression pathway.SignificancePolycomb group (PcG) proteins are employed by a wide variety of eukaryotes for the maintenance of gene repression. Polycomb repressive complex 2 (PRC2), a multimeric complex of PcG proteins, catalyzes the methylation of histone H3 lysine 27 (H3K27). In the filamentous fungus, Neurospora crassa, H3K27 methylation represses scores of genes, despite the absence of canonical H3K27 methylation effectors that are present in plants and animals. We report the identification and characterization of an H3K27 methylation effector, EPR-1, in N. crassa and demonstrate its widespread presence and early eukaryotic origins with phylogenetic analyses. These findings indicate that an ancient EPR-1 may have been part of a nascent Polycomb repression system in eukaryotes.

scholarly journals Gfi1 Coordinates Epigenetic Repression of p21Cip/WAF1 by Recruitment of Histone Lysine Methyltransferase G9a and Histone Deacetylase 1

2005 ◽  
Vol 25 (23) ◽  
pp. 10338-10351 ◽  
Author(s):  
Zhijun Duan ◽  
Adrian Zarebski ◽  
Diego Montoya-Durango ◽  
H. Leighton Grimes ◽  
Marshall Horwitz
Keyword(s):  
Cell Fate ◽  
Histone Deacetylase ◽  
Histone H3 ◽  
Hematopoietic Stem ◽  
Histone Deacetylase 1 ◽  
Histone Lysine ◽  
Histone Lysine Methyltransferase ◽  
Lysine Methyltransferase ◽  
Cell Processes ◽  
Epigenetic Repression

ABSTRACT The growth factor independent 1 (Gfi1) transcriptional regulator oncoprotein plays a crucial role in hematopoietic, inner ear, and pulmonary neuroendocrine cell development and governs cell processes as diverse as self-renewal of hematopoietic stem cells, proliferation, apoptosis, differentiation, cell fate specification, and oncogenesis. However, the molecular basis of its transcriptional functions has remained elusive. Here we show that Gfi1 recruits the histone lysine methyltransferase G9a and the histone deacetylase 1 (HDAC1) in order to modify the chromatin of genes targeted for repression by Gfi1. G9a and HDAC1 are both in a repressive complex assembled by Gfi1. Endogenous Gfi1 colocalizes with G9a, HDAC1, and K9-dimethylated histone H3. Gfi1 associates with G9a and HDAC1 on the promoter of the cell cycle regulator p21 Cip/WAF1 , resulting in an increase in K9 dimethylation at histone H3. Silencing of Gfi1 expression in myeloid cells reverses G9a and HDAC1 recruitment to p21 Cip/WAF1 and elevates its expression. These findings highlight the role of epigenetics in the regulation of development and oncogenesis by Gfi1.

scholarly journals SETDB1-Mediated Silencing of Retroelements

Viruses ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 596 ◽  
Author(s):  
Kei Fukuda ◽  
Yoichi Shinkai
Keyword(s):  
Genome Stability ◽  
Histone H3 ◽  
Endogenous Retroviruses ◽  
H3k9 Methylation ◽  
Epigenetic Factors ◽  
Set Domain ◽  
H3k9 Trimethylation ◽  
Histone Lysine ◽  
Histone Lysine Methyltransferase ◽  
Lysine Methyltransferase

SETDB1 (SET domain bifurcated histone lysine methyltransferase 1) is a protein lysine methyltransferase and methylates histone H3 at lysine 9 (H3K9). Among other H3K9 methyltransferases, SETDB1 and SETDB1-mediated H3K9 trimethylation (H3K9me3) play pivotal roles for silencing of endogenous and exogenous retroelements, thus contributing to genome stability against retroelement transposition. Furthermore, SETDB1 is highly upregulated in various tumor cells. In this article, we describe recent advances about how SETDB1 activity is regulated, how SETDB1 represses various types of retroelements such as L1 and class I, II, and III endogenous retroviruses (ERVs) in concert with other epigenetic factors such as KAP1 and the HUSH complex and how SETDB1-mediated H3K9 methylation can be maintained during replication.

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