• Animal cells and systems
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• v.16 no.4
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• pp.289-294
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• 2012

Histone methylation has diverse functions including transcriptional regulation via its lysine or arginine residue methylation. Studies indicate that deregulation of histone methylation is linked to human cancers including leukemia. Histone H3K27 methyltrnasferase response element II binding protein (RE-IIBP), as a transcriptional repressor to target gene IL-5, interacts with HDAC and is over-expressed in leukemia patient samples. In this study, we have identified that hematopoiesis-related genes GATA1 and HOXA9 are down-regulated by RE-IIBP in K562 and 293T cells. Transient reporter analysis revealed that GATA1 transcription was repressed by RE-IIBP. On the other hand, HOXA9 and PBX-related homeobox gene MEIS1 was up-regulated by RE-IIBP. These results suggest that RE-IIBP might have a role in hematopoiesis or leukemogenesis by regulating the transcription of target genes, possibly via its H3K27 methyltransferase activity.

• Journal of Life Science
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• v.28 no.12
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• pp.1536-1544
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• 2018

Depression is a common, serious, and recurring mental disorder. The pathogenesis of depression involves many factors such as environmental factor, genetic factor and alteration of structure and function in neurobiological systems. Increasing evidence supports that epigenetic alteration may be associated with depression. The epigenetics is explained as the mechanisms by which environmental factor causes changes in chromatin structure and alters gene expression without changing DNA base sequence. DNA methylation and histone modification involving histone acetylation and methylation are the main epigenetic mechanisms. Animal studies have shown that stressful environment such as early life stress can leave persistent epigenetic marks in the genome, which alter gene expression and influence neural and behavioral function through adulthood. A potentially important gene in depression is brain-derived neurotrophic factor (BDNF). BDNF plays a central role in depression and antidepressant action. In studies of the rodent, exposure to stress at prenatal, postnatal, and adult stages alters BDNF expression through histone modification and DNA methylation of the BDNF gene which results in anxiety and depressive-like behavior. This review discusses recent advances in the study of the epigenetic mechanisms that contribute to depression, particularly histone modification and DNA methylation of the BDNF gene, that may help in the development of new targets for depression treatment.

• Interdisciplinary Bio Central
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• v.1 no.1
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• pp.4.1-4.7
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• 2009

Introduction: Histone modifications and DNA methylation are the major factors in epigenetic gene regulation. Especially, revealing how histone modifications are related to DNA methylation is one of the challenging problems in this field. In this paper, we address this issue and propose several plausible mechanisms for precise controlling of DNA methylation status at CpG islands. Materials and Methods: To establish the regulatory relationships, we used 38 histone modification types including H2A.Z and CTCF, and DNA methylation status at CpG islands across chromosome 6, 20, and 22 of human CD4+ T cell. We utilized Bayesian network to construct regulatory network. Results and Discussion: We found several meaningful relationships supported by previous studies. In addition, our results show that histone modifications can be clustered into several groups with different regulatory properties. Based on those findings we predicted the status of methylation level at CpG islands with high accuracy, and suggested core-regulatory network to control DNA methylation status.

• Genomics & Informatics
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• v.8 no.4
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• pp.201-205
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• 2010

The H1 histone family, member N, testis-specific (H1FNT) is exclusively expressed in the testis, and had its possible role for sperm chromatin formation. The purpose of this study is to investigate any genetic association of H1FNT gene with male infertility, especially at the promoter region. We examined the promoter single nucleotide polymorphisms (SNP) of H1FNT gene which is located within transcription factor binding site for its association with male infertility. The statistical analysis showed that the -1129A>T polymorphism was present at a statistically significance in male infertility (p=0.0059 and 0.0349 for hetero and risk type, respectively). The dual-luciferase promoter assay was performed to examine the polymorphic effect of this promoter SNP by the cloning of promoter region (1700bp fragment) into pGL3-basic vector. In our plasmid based reporter system, there is no big difference between wild and risk type. In conclusion, H1FNT -1129A>T promoter SNP is statistically significant with male infertility, especially with subfertile (non-azoospermia) group. Further analysis of its functional polymorphic effect in vivo may provide the biological significance of testis-specific histone with spermatogenesis.

• Journal of Microbiology and Biotechnology
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• v.28 no.9
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• pp.1573-1579
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• 2018

Transcriptional gene silencing is regulated by the chromatin structure, which is by various factors including histones. Saccharomyces cerevisiae contains transcriptionally silenced regions such as telomeric regions and hidden mating (HM) loci. The positively-charged amino acids on the histone H4 tail were reported to be critical for the telomeric silencing in yeast, by interacting with Dot1, a specific methyltransferase for the $79^{th}$ lysine on histone H3. However, Dot1 did not affect gene silencing within HM loci, but whether the positively-charged amino acids on the H4 tail affect HM silencing has not been defined. To elucidate the function of the H4 tail on HM silencing, we created several MATa-type yeast strains bearing the substitution of arginine with alanine or lysine on the histone H4 tail and checked the sensitivity of MATa-type yeast to alpha pheromone. The arginine point mutants substituted by alanine (R17A, R19A, and R23A) did not show sensitivity to alpha pheromone, but only two arginine mutants substituted by lysine (R17K and R19K) restored the sensitivity to alpha pheromone-like wild type. These data suggested that the basic property of arginine at $17^{th}$ and $19^{th}$ positions in the histone H4 tail is critical for maintaining HM silencing, but that of the $23^{rd}$ arginine is not. Our data implicated that the positive charge of two arginine residues on the histone H4 tail is required for HM silencing in a manner independent of Dot1.

• Journal of Life Science
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• v.21 no.4
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• pp.616-620
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• 2011

Lysine residues of histone H3 and H4 are covalently modified in the chromatin of eukaryotic cells. Lysine 27 in histone H3 was acetylated (H3K27ac) or methylated at three levels; mono-, di-, and trimethylation (H3K27me1, H3K27me2, and H3K27me3). These modifications at H3K27 were related with gene transcription and/or chromatin structure in distinct patterns. Generally, H3K27ac and H3K27me1 were enriched in active chromatin, such as the locus control region or transcriptionally active genes, while transcriptionally inactive genes were highly marked by H3K27me2 and H3K27me3. These modifications appear to have been catalyzed by distinct histone-modifying enzymes. Recent studies suggest that the four kinds of modifications at H3K27 have inter-correlation in gene transcription or chromatin structure formation.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.184.1-184.1
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• 2003

HDAC and HAT (histone acetyltransferase) are involved in co-regulation in chromatin remodeling and the functional regulation of gene transcription. Abnormal recruitment of HDAC is related to carcinogenesis. Thus, the identification of potent histone deacetylase (HDAC) inhibitor has been considered as very intriguing approach for development for cancer chemotherapy. More recently, anti-inflammatory activity of SAHA cytokines was reported via reduction of proinflammatory cytokinres in vitro and in vivo. (omitted)

• Journal of Microbiology and Biotechnology
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• v.28 no.7
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• pp.1185-1198
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• 2018

The nucleosomal organization of chromatin using histone proteins is a fundamental and ubiquitous feature of eukaryotic nuclei, with the major exception of dinoflagellates. Although a number of recent genomic and transcriptomic analyses have detected numerous histone genes in dinoflagellates, little is known about their expression. Here in, we aimed to investigate the expression pattern of histone genes under nutritional stress, and an attempt was made to detect histone expression at the protein level in Alexandrium pacificum. The presence of histones at the mRNA level was confirmed in this study by the amplification, cloning, and sequencing of 10 different genes. Relative expression profiling of these genes under different growth conditions was determined with real-time PCR and revealed considerable levels of histone transcription in nutritionally stressed cells. We were unable to detect the expression of histones at the protein level even after immunodetection and analysis using mass spectrometry, although a histone-like protein was detected as a major nuclear component. A. pacificum expresses multiple variants of histone, and protein sequences revealed both conservation and divergence with respect to other eukaryotes. We concluded that A. pacificum maintained an active transcription of histone genes within the cell, and enhanced expression of histone genes in nutritional stress strongly suggest that histones have functional significance in dinoflagellates, although expression at the protein level was below our current detection limits, which suggests a limited role of histones in DNA packaging. Finally, the plausible regulation of histone expression at the gene and protein levels in A. pacificum is discussed.

• Proceedings of the Korean Society of Applied Pharmacology
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• 2001.11a
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• pp.110-110
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• 2001

Histone deacetylase(HDAC), a neuclear enzyme that regulates gene trascription and the assembly of newly synthesized chromatin, has received much attention in recent literature. The explosion of activity in this field has yielded the cloning of a mammalian gene which encodes a complementary histone acetyl trasferases. Several cyclic tetrapeptide inhibitors of HDAC has been reported to affect the hyperacetylation of mammalian and plant histones. Apicidin, a natural product HDAC inhibitor recently isolated at Merck Research Laboratories, induces therapeutic applications as a broad spectrum antiprotozoal agent to multi-drug resistant malaria and a potential antitumor agnet. The biological activity of apicidin appears to be attributable to inhibition of apicocomplexan HDAC at low nanomolar concentrations.

• Molecules and Cells
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• v.43 no.4
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• pp.323-330
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• 2020

Epigenetic events like DNA methylation and histone modification can alter heritable phenotypes. Zinc is required for the activity of various epigenetic enzymes, such as DNA methyltransferases (DNMTs), histone acetyltransferases (HATs), histone deacetylases (HDACs), and histone demethylases, which possess several zinc binding sites. Thus, the dysregulation of zinc homeostasis can lead to epigenetic alterations. Zinc homeostasis is regulated by Zinc Transporters (ZnTs), Zrt- and Irt-like proteins (ZIPs), and the zinc storage protein metallothionein (MT). Recent advances revealed that ZIPs modulate epigenetics. ZIP10 deficiency was found to result in reduced HATs, confirming its involvement in histone acetylation for rigid skin barrier formation. ZIP13 deficiency, which is associated with Spondylocheirodysplastic Ehlers-Danlos syndrome (SCD-EDS), increases DNMT activity, leading to dysgenesis of dermis via improper gene expressions. However, the precise molecular mechanisms remain to be elucidated. Future molecular studies investigating the involvement of zinc and its transporters in epigenetics are warranted.