title: DNA-PK-mediated phosphorylation of EZH2 regulates the DNA damage-induced apoptosis to maintain T-cell genomic integrity.
abstract: EZH2 is a histone methyltransferase whose functions in stem cells and tumor cells are well established. Accumulating evidence shows that EZH2 has critical roles in T cells and could be a promising therapeutic target for several immune diseases. To further reveal the novel functions of EZH2 in human T cells, protein co-immunoprecipitation combined mass spectrometry was conducted and several previous unknown EZH2-interacting proteins were identified. Of them, we focused on a DNA damage responsive protein, Ku80, because of the limited knowledge regarding EZH2 in the DNA damage response. Then, we demonstrated that instead of being methylated by EZH2, Ku80 bridges the interaction between the DNA-dependent protein kinase (DNA-PK) complex and EZH2, thus facilitating EZH2 phosphorylation. Moreover, EZH2 histone methyltransferase activity was enhanced when Ku80 was knocked down or DNA-PK activity was inhibited, suggesting DNA-PK-mediated EZH2 phosphorylation impairs EZH2 histone methyltransferase activity. On the other hand, EZH2 inhibition increased the DNA damage level at the late phase of T-cell activation, suggesting EZH2 involved in genomic integrity maintenance. In conclusion, our study is the first to demonstrate that EZH2 is phosphorylated by the DNA damage responsive complex DNA-PK and regulates DNA damage-mediated T-cell apoptosis, which reveals a novel functional crosstalk between epigenetic regulation and genomic integrity.
authors.affiliation: Shanghai Public Health Clinical Center and Shanghai Key Laboratory of Organ Transplantation, Zhongshan Hospital, Fudan University, Shanghai 200032, China.|Key Laboratory of Stem Cell Biology, Institute of Health Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences & Shanghai Jiao Tong University School of Medicine (SJTUSM) and Shanghai Institute of Immunology, Institutes of Medical Sciences, SJTUSM, Shanghai 200031, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Key Laboratory of Stem Cell Biology, Institute of Health Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences & Shanghai Jiao Tong University School of Medicine (SJTUSM) and Shanghai Institute of Immunology, Institutes of Medical Sciences, SJTUSM, Shanghai 200031, China.|Department of Microbiology and Immunology, Fels Institute for Cancer Research and Molecular Biology, Temple University, Philadelphia, PA 19104, USA.
authors.forename: H
authors.initials: H
authors.lastname: Sun
authors.affiliation: Shanghai Public Health Clinical Center and Shanghai Key Laboratory of Organ Transplantation, Zhongshan Hospital, Fudan University, Shanghai 200032, China.
authors.forename: J
authors.initials: J
authors.lastname: Wang
authors.affiliation: Key Laboratory of Stem Cell Biology, Institute of Health Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences & Shanghai Jiao Tong University School of Medicine (SJTUSM) and Shanghai Institute of Immunology, Institutes of Medical Sciences, SJTUSM, Shanghai 200031, China.
authors.forename: H
authors.initials: H
authors.lastname: Wang
authors.affiliation: Key Laboratory of Stem Cell Biology, Institute of Health Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences & Shanghai Jiao Tong University School of Medicine (SJTUSM) and Shanghai Institute of Immunology, Institutes of Medical Sciences, SJTUSM, Shanghai 200031, China.
authors.forename: L
authors.initials: L
authors.lastname: Meng
authors.affiliation: Key Laboratory of Stem Cell Biology, Institute of Health Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences & Shanghai Jiao Tong University School of Medicine (SJTUSM) and Shanghai Institute of Immunology, Institutes of Medical Sciences, SJTUSM, Shanghai 200031, China.
authors.forename: C
authors.initials: C
authors.lastname: Xu
authors.affiliation: Key Laboratory of Stem Cell Biology, Institute of Health Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences & Shanghai Jiao Tong University School of Medicine (SJTUSM) and Shanghai Institute of Immunology, Institutes of Medical Sciences, SJTUSM, Shanghai 200031, China.
authors.forename: M
authors.initials: M
authors.lastname: Jin
authors.affiliation: Key Laboratory of Stem Cell Biology, Institute of Health Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences & Shanghai Jiao Tong University School of Medicine (SJTUSM) and Shanghai Institute of Immunology, Institutes of Medical Sciences, SJTUSM, Shanghai 200031, China.
authors.forename: B
authors.initials: B
authors.lastname: Wang
authors.affiliation: Shanghai Public Health Clinical Center and Shanghai Key Laboratory of Organ Transplantation, Zhongshan Hospital, Fudan University, Shanghai 200032, China.|Key Laboratory of Stem Cell Biology, Institute of Health Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences & Shanghai Jiao Tong University School of Medicine (SJTUSM) and Shanghai Institute of Immunology, Institutes of Medical Sciences, SJTUSM, Shanghai 200031, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Shanghai Public Health Clinical Center and Shanghai Key Laboratory of Organ Transplantation, Zhongshan Hospital, Fudan University, Shanghai 200032, China.|Department of Microbiology and Immunology, Fels Institute for Cancer Research and Molecular Biology, Temple University, Philadelphia, PA 19104, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Shanghai Public Health Clinical Center and Shanghai Key Laboratory of Organ Transplantation, Zhongshan Hospital, Fudan University, Shanghai 200032, China.
authors.forename: T
authors.initials: T
authors.lastname: Zhu
mesh_terms: D017209:Apoptosis; D018414:CD8-Positive T-Lymphocytes / Q000378:metabolism; D004249:DNA Damage; D051747:DNA-Activated Protein Kinase / Q000378:metabolism*; D000071221:Enhancer of Zeste Homolog 2 Protein / Q000037:antagonists & inhibitors / Q000378:metabolism*; D042822:Genomic Instability; D006801:Humans; D019169:Jurkat Cells; D000072200:Ku Autoantigen / Q000378:metabolism; D013058:Mass Spectrometry; D008745:Methylation; D010766:Phosphorylation; D011485:Protein Binding; D013601:T-Lymphocytes / Q000166:cytology* / Q000378:metabolism*
chemical_list: C498409:EZH2 protein, human; D000071221:Enhancer of Zeste Homolog 2 Protein; D051747:DNA-Activated Protein Kinase; D000072200:Ku Autoantigen