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Signal transduction and exercise
Published in Adam P. Sharples, James P. Morton, Henning Wackerhage, Molecular Exercise Physiology, 2022
Brendan Egan, Adam P. Sharples
The tight packaging of DNA in chromatin must be unravelled before a gene can be transcribed. The packaging and unpackaging of DNA are known as chromatin remodelling and histone modifications are key mechanisms in the regulation of this process. Mapping of packaged and unpackaged DNA on a genome-wide scale has revealed that histone tail modifications are cell-specific and mark genes, transcription start sites and stretches of regulatory DNA, via which gene expression is regulated (53). Indeed, signal transduction pathways modulate chromatin remodelling by methylating (CH3, methyl group), acetylating (CH3CO, acetyl group) and phosphorylating histone proteins, especially in the tail regions of histones H3 and H4 (19, 20). The enzymes that catalyse these modifications include histone methyltransferases and histone demethylases as well as histone acetyltransferases and HDACs. The resultant modifications are abbreviated stating first the histone number, second the amino acid which is modified and finally the type of modification (ac stands for acetylation, me1, me2, m3 for methylation, dimethylation and trimethylation, respectively). For example, H3K27me3 refers to the trimethylation of lysine 27 (K is the one-letter abbreviation for lysine) of histone 3.
Role of Histone Methyltransferase in Breast Cancer
Published in Meenu Gupta, Rachna Jain, Arun Solanki, Fadi Al-Turjman, Cancer Prediction for Industrial IoT 4.0: A Machine Learning Perspective, 2021
Surekha Manhas, Zaved Ahmed Khan
Histone methyltransferases represent the class of histone-modifying enzymes whose function is to transfer the alkyl group from methyl donating molecule S-Adenosyl-L-methionine onto the residues of arginine or lysine of the H3 and H4 histones. Alteration in the histones is responsible for various insidious diseases, including cancer, by leading to pro-apoptotic protein downregulations or tumor suppressor silencing.
Role of Epigenetics in Immunity and Immune Response to Vaccination
Published in Mesut Karahan, Synthetic Peptide Vaccine Models, 2021
The modification reaction is catalyzed by histone methyltransferases where methyl groups from S-adenosyl methionines (SAM) are transferred to amino acid residues on H3 and H4 histones (Bannister and Kouzarides 2011).
Epigenetic regulation of T cell development
Published in International Reviews of Immunology, 2023
Avik Dutta, Harini Venkataganesh, Paul E. Love
Major histone epigenetic marks are methylation, acetylation and ubiquitination. Histone methyltransferases (HMT) catalyze the transfer of one, two, or three methyl groups to lysine (K = Lysine) or arginine (R = Arginine) residues of histone (H3 and H4) proteins [22]. There are three major types of histone methyltransferases, including SET domain containing (e.g. Setd1, Setd2, mixed lineage leukemia (MLL)1/2), non-SET domain containing (e.g. DOT1L) and arginine-specific (e.g. PRMT1) HMTs [22]. Trimethylation of lysine 9 of histone H3 [H3K9], lysine 27 [H3K27] or lysine 20 of Histone 4 [H4K20] are mainly found in heterochromatin and serve as transcriptional repressive marks [23]. On the other hand, H3K4, H3K36 and H3K79 are enriched in euchromatin and are usually associated with active transcription (Figure 1) [24].
Chaetocin induced chromatin condensation: effect on DNA repair signaling and survival
Published in International Journal of Radiation Biology, 2021
A. Sak, K. Bannik, M. Groneberg, M. Stuschke
The fungal metabolite chaetocin, a member of epipolythiodiketopiperazines (EPTs) which targets histone methyltransferases (HMTs), was used in the present study to modulate the chromatin structure. Chaetocin has been found to be an inhibitor of the HKMT Suv39 family, including SUV39h1 with an IC50 of 0.8 μM, and did not inhibit other HKMTs such as EZH2 or SET7/9 at concentrations below 90 μM, suggesting its potential selectivity (Greiner et al. 2005). Chaetocin has also been reported to inhibit SUV39h1 activity in acute myeloid leukemia cells with hypermethylated tumor suppressor genes and thus exhibited anti-myeloma activity (Lakshmikuttyamma et al. 2010). Although the human HKMT SUV39h1 was shown to be altered in various types of human cancers (Pandey et al. 2014), its functional role in the radiation response of human lung cancer cell lines remains unclear. Thus, the present study explores the effect of chaetocin on the radiation response with respect to cell cycle progression, repair, apoptosis, and radiation sensitivity by measuring clonogenic survival as well as growth control of plaque-monolayers of non-small cell lung cancer (NSCLC) cell lines.
p300 Acetylates JHDM1A to inhibit osteosarcoma carcinogenesis
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2019
Yongkun Wang, Baozhen Sun, Qiao Zhang, Hang Dong, Jingzhe Zhang
Dysregulation of histone methyltransferases and demethylases has been considered as an important epigenetic mechanism related to cancer onset and progression [22]. As a histone demethylase, JHDM1A has been demonstrated to be up-regulated in many cancer cells, such as non-small cell lung cancer [10], ovarian cancer [16], breast cancer [23] and gastric cancer [24]. p300 is an acetyltransferase in cells, which can acetylate many proteins in cells and take part in the modulation of many cellular biological processes, including cell cycle transition [25], DNA synthesis [26], cell autophagy [27], cell proliferation [28] and cell apoptosis [29]. The tumor suppressive role of p300 has been widely studied [30]. p300 gene mutations, especially mutations at the sequence encoding the acetyltransferase, have been discovered to exist in many human cancers [31]. In terms of osteosarcoma, Sui et al. reported that p300 exhibit tumor suppressive activity via acetylating p53 and then up-regulating p21 and Bax expression [32]. Herein, we found that p300 could interact with JHDM1A and directly acetylate JHDM1A at K409 residue in osteosarcoma MG-63 and HOS cells, which implied that p300 exert tumor suppressive roles in osteosarcoma cells might be via acetylating JHDM1A.