• The Plant Pathology Journal
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• v.33 no.2
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• pp.193-205
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• 2017

Histone methylation plays important roles in regulating chromatin dynamics and transcription in eukaryotes. Implication of histone modifications in fungal pathogenesis is, however, beginning to emerge. Here, we report identification and functional analysis of a putative JmjC-domain-containing histone demethylase in Magnaporthe oryzae. Through bioinformatics analysis, we identified seven genes, which encode putative histone demethylases containing JmjC domain. Deletion of one gene, MoJMJ1, belonging to JARID group, resulted in defects in vegetative growth, asexual reproduction, appressorium formation as well as invasive growth in the fungus. Western blot analysis showed that global H3K4me3 level increased in the deletion mutant, compared to wild-type strain, indicating histone demethylase activity of MoJMJ1. Introduction of MoJMJ1 gene into ${\Delta}Mojmj1$ restored defects in pre-penetration developments including appressorium formation, indicating the importance of histone demethylation through MoJMJ1 during infection-specific morphogenesis. However, defects in penetration and invasive growth were not complemented. We discuss such incomplete complementation in detail here. Our work on MoJMJ1 provides insights into H3K4me3-mediated regulation of infection-specific development in the plant pathogenic fungus.

• Molecules and Cells
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• v.37 no.10
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• pp.734-741
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• 2014

Histone modifications on major transcription factor target genes are one of the major regulatory mechanisms controlling adipogenesis. Plant homeodomain finger 2 (PHF2) is a Jumonji domain-containing protein and is known to demethylate the histone H3K9, a repressive gene marker. To better understand the function of PHF2 in adipocyte differentiation, we constructed stable PHF2 knock-down cells by using the mouse pre-adipocyte cell line 3T3-L1. When induced with adipogenic media, PHF2 knock-down cells showed reduced lipid accumulation compared to control cells. Differential expression using a cDNA microarray revealed significant reduction of metabolic pathway genes in the PHF2 knock-down cell line after differentiation. The reduced expression of major transcription factors and adipokines was confirmed with reverse transcription- quantitative polymerase chain reaction and Western blotting. We further performed co-immunoprecipitation analysis of PHF2 with four major adipogenic transcription factors, and we found that CCATT/enhancer binding protein (C/EBP)${\alpha}$ and C/EBP${\delta}$ physically interact with PHF2. In addition, PHF2 binding to target gene promoters was confirmed with a chromatin immunoprecipitation experiment. Finally, histone H3K9 methylation markers on the PHF2-binding sequences were increased in PHF2 knock-down cells after differentiation. Together, these results demonstrate that PHF2 histone demethylase controls adipogenic gene expression during differentiation.

• BMB Reports
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• v.42 no.3
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• pp.154-159
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• 2009

JARID1B (jumonji AT rich interactive domain 1B) is a large nuclear protein that is highly expressed in breast cancers and is proposed to function as a repressor of gene expression. In this paper, a phage display screen using the N-terminus of JARID1B as bait identified one of the JARID1B interacting proteins, namely PcG protein (Polycomb group) hPc2. We demonstrated that the C-terminal region, including the COOH box, was required for the interaction with the N-terminus of JARID1B. In a reporter assay system, co-expression of JARID1B with hPc2 significantly enhanced the transcriptional repression. These results support a role for hPc2 acting as a transcriptional co-repressor.

• BMB Reports
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• v.50 no.1
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• pp.49-54
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• 2017

Previously, we reported that vitamin C facilitates the CpG demethylation of Foxp3 enhancer in $CD4^+Foxp3^+$ regulatory T cells (Tregs) by enhancing the activity of a DNA demethylase ten-eleven-translocation (Tet). However, it is not clear whether vitamin C affects other helper T cell lineages like T helper type 17 (Th17) cells which are related with Tregs. Here, we show that the expression of interleukin-17A (IL17) increases with the treatment of vitamin C but not with other antioxidants. Interestingly, the upregulation of IL17 was not accompanied by DNA demethylation in Il17 promoter and was independent of Tet enzymes. Rather, vitamin C reduced the trimethylation of histone H3 lysine 9 (H3K9me3) in the regulatory elements of the Il17 locus, and the effects of vitamin C were abrogated by knockdown of jumonji-C domain-containing protein 2 (jmjd2). These results suggest that vitamin C can affect the expression of IL17 by modulating the histone demethylase activity.

• Molecules and Cells
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• v.42 no.7
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• pp.530-545
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• 2019

Tumor cells can vary epigenetically during ionizing irradiation (IR) treatment. These epigenetic variegations can influence IR response and shape tumor aggressiveness. However, epigenetic disturbance of histones after IR, implicating in IR responsiveness, has been elusive. Here, we investigate whether altered histone modification after IR can influence radiation responsiveness. The oncogenic CXCL12 mRNA and protein were more highly expressed in residual cancer cells from a hepatoma heterotopic murine tumor microenvironment and coculture of human hepatoma Huh7 and normal IMR90 cells after radiation. H3K4 methylation was also enriched and H3K9 methylation was decreased at its promoter region. Accordingly, invasiveness and the subpopulation of aggressive $CD133^+/CD24^-$ cells increased after IR. Histone demethylase inhibitor IOX1 attenuated CXCL12 expression and the malignant subpopulation, suggesting that responses to IR can be partially mediated via histone modifications. Taken together, radiation-induced histone alterations at the CXCL12 promoter in hepatoma cells are linked to CXCL12 upregulation and increased aggressiveness in the tumor microenvironment.

• Molecules and Cells
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• v.37 no.1
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• pp.43-50
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• 2014

Jumonji domain-containing proteins (JMJD) catalyze the oxidative demethylation of a methylated lysine residue of histones by using $O_2$, ${\alpha}$-ketoglutarate, vitamin C, and Fe(II). Several JMJDs are induced by hypoxic stress to compensate their presumed reduction in catalytic activity under hypoxia. In this study, we showed that an H3K27me3 specific histone demethylase, JMJD3 was induced by hypoxia-inducible factor (HIF)-$1{\alpha}/{\beta}$ under hypoxia and that treatment with Clioquinol, a HIF-$1{\alpha}$ activator, increased JMJD3 expression even under normoxia. Chromatin immunoprecipitation (ChIP) analyses showed that both HIF-$1{\alpha}$ and its dimerization partner HIF-$1{\beta}$/Arnt occupied the first intron region of the mouse JMJD3 gene, whereas the HIF-$1{\alpha}/{\beta}$ heterodimer bound to the upstream region of the human JMJD3, indicating that human and mouse JMJD3 have hypoxia-responsive regulatory regions in different locations. This study shows that both mouse and human JMJD3 are induced by HIF-1.

• Molecules and Cells
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• v.40 no.10
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• pp.737-751
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• 2017

Histone-modifying enzymes are key players in the field of cellular differentiation. Here, we used GSK-J4 to profile important target genes that are responsible for neural differentiation. Embryoid bodies were treated with retinoic acid ($10{\mu}M$) to induce neural differentiation in the presence or absence of GSK-J4. To profile GSKJ4-target genes, we performed RNA sequencing for both normal and demethylase-inhibited cells. A total of 47 and 58 genes were up- and down-regulated, respectively, after GSK-J4 exposure at a log2-fold-change cut-off value of 1.2 (p-value < 0.05). Functional annotations of all of the differentially expressed genes revealed that a significant number of genes were associated with the suppression of cellular proliferation, cell cycle progression and induction of cell death. We also identified an enrichment of potent motifs in selected genes that were differentially expressed. Additionally, we listed upstream transcriptional regulators of all of the differentially expressed genes. Our data indicate that GSK-J4 affects cellular biology by inhibiting cellular proliferation through cell cycle suppression and induction of cell death. These findings will expand the current understanding of the biology of histone-modifying enzymes, thereby promoting further investigations to elucidate the underlying mechanisms.

• Journal of Life Science
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• v.17 no.3 s.83
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• pp.444-453
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• 2007

Our genome exists in the form of chromatin, and its structural organization should be precisely regulated with an appropriate dynamic nature for life. The basic unit of chromatin is a nucleosome, which consists of a histone octamer. These nucleosomal histones are subject to various covalent modifications, one of which is methylation on certain lysine residues. Recent studies in histone biology identified many histone Iysine methyltransferases (HKMTs) responsible for respective lysine residues and uncovered various kinds of involved chromatin associating proteins and many related epigenetic phenotypes. With the aid of highly precise experimental tools, multi-disciplinary approaches have widened our understanding of how lysine methylation functions in diverse epigenetic processes though detailed mechanisms remain elusive. Still being considered as a relatively more stable mark than other modifications, the recent discovery of lysine demethylases will confer more flexibility on epigenetic memory transmitted through histone lysine methylation. In this review, advances that have been recently observed in epigenetic phenotypes related with histone lysine methylation and the enzymes for depositing and removing the methyl mark are provided.

• BMB Reports
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• v.48 no.7
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• pp.401-406
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• 2015

Here we report that the H3K9 demethylase KDM3B represses transcription of the angiogenesis regulatory gene, ANGPT1. Negative regulation of ANGPT1 by KDM3B is independent of its Jumonji (JmjC) domain-mediated H3K9 demethylase activity. We demonstrate that KDM3B downregulates ANGPT1 via interaction with SMRT, and suggest that the repressor complex is formed at the promoter area of ANGPT1. Using MTT and wound healing assays, depletion of KDM3B was found to increase cell proliferation and cell motility, indicating that KDM3B has a role in angiogenesis. [BMB Reports 2015; 48(7): 401-406]

• Molecules and Cells
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• v.27 no.4
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• pp.481-490
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• 2009

Diverse posttranslational modifications of histones, such as acetylation and methylation, play important roles in controlling gene expression. Histone methylation in particular is involved in a broad range of biological processes, including heterochromatin formation, X-chromosome inactivation, genomic imprinting, and transcriptional regulation. Recently, it has been demonstrated that proteins containing the Jumonji (Jmj) C domain can demethylate histones. In Arabidopsis, twenty-one genes encode JmjC domain-containing proteins, which can be clustered into five clades. To address the biological roles of the Arabidopsis genes encoding JmjC-domain proteins, we analyzed the temporal and spatial expression patterns of nine genes. RT-PCR analyses indicate all nine Arabidopsis thaliana Jmj (AtJmj) genes studied are actively expressed in various tissues. Furthermore, studies of transgenic plants harboring AtJmj::${\beta}$-glucuronidase fusion constructs reveal that these nine AtJmj genes are expressed in a developmentally and spatially regulated manner.