Role of Histon H2A deubiquitinase 2A-DUB/Mysm1 in lymphoid development and interaction with p53-mediated apoptotic programs

组蛋白 H2A 去泛素酶 2A-DUB/Mysm1 在淋巴发育中的作用以及与 p53 介导的细胞凋亡程序的相互作用

• 批准号: 266397124
• 负责人: Privatdozentin Dr. Martina Gatzka
• 金额: --
• 依托单位: Universitätsklinik für Dermatologie und Allergologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2014
• 资助国家: 德国
• 起止时间: 2013-12-31 至 2018-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/266397124?language=en
• 关键词: Role; Histon; H2A; deubiquitinase; 2A

Sequential differentiation of specialized cell populations from pluripotent progenitors requires the collaboration of histone modifying and chromatin remodeling enzymes with sequence-specific DNA binding transcription factors (TF) in larger multi-protein complexes to activate and silence lineage-specific genes in a coordinated manner. Histone H2A deubiquitinase 2A-DUB/Mysm1, an epigenetic regulator highly expressed in lymphocytes and the skin, potentially fulfills several critical functions at different stages of hematopoietic and skin development: 1. In the DNA-damage response (DDR) required for efficient somatic recombination of T cell receptor (TCR) and immunoglobin (Ig) genes during early lymphocyte development. 2. In regulating access of sequence-specific TFs to DNA during differentiation of lymphocytes and skin cells. 3. In the DDR induced by reactive oxygen species (ROS) and irradiation. Therefore, H2A deubiquitination by 2A-DUB/Mysm1 might be involved in regulating protection from autoimmunity, lymphoma and cancer. Because mice with an engineered deficiency in 2A-DUB/Mysm1 (Mysm1 KO mice) have a number of defects in T cell and skin development - including severe thymus hypoplasia along with altered activation of peripheral T cells, skin atrophy and premature aging -, we propose here to characterize the role of Mysm1 in T cells, the skin, and in associated diseases using genetic, immunological and molecularbiological approaches. Based on the applicants preliminary data identifying the Ink4/ARF pathway as potential mediator of increased apoptosis and reduced proliferation rates in Mysm1-deficient thymocytes and epidermal cells, the interplay of 2A-DUB/Mysm1 with the p19ARF/Ink4a promoter will be investigated and verified in our newly generated p53-/-Mysm1-/- and Cdkn2a/ARF-/- Mysm1-/- double-KO (DKO) mice. The role of histone H2A deubiquitination by Mysm1 in thymocyte development and selection will be explored in Lck-Cre x Mysm1flox/flox mice as well as in p53-/-Mysm1-/- DKO and H-Y TCR transgenic mice. Additional molecular interactions and binding partners of Mysm1 in T cell and skin cell populations will be verified by ChIP-based approaches. Ultimately, the impact of potential alterations in the T cell repertoire or in genetic instability in T cells and skin cells as a consequence of Mysm1-deficiency will be explored in autoimmune and tumor models in a translational approach. This investigation aims at providing a better understanding of how epigenetic mechanisms interact with lineage-specific TFs and differentiation programs to regulate T cell and skin development and how epigenetics contribute to the prevention of autoimmunity and cancer.

从多能祖细胞中连续分化出特化细胞群需要组蛋白修饰酶和染色质重塑酶与较大多蛋白复合物中序列特异性 DNA 结合转录因子 (TF) 的协作，以协调的方式激活和沉默谱系特异性基因。组蛋白 H2A 去泛素酶 2A-DUB/Mysm1 是一种在淋巴细胞和皮肤中高度表达的表观遗传调节因子，可能在造血和皮肤发育的不同阶段发挥多种关键功能： 1. 在早期 T 细胞受体 (TCR) 和免疫球蛋白 (Ig) 基因有效体细胞重组所需的 DNA 损伤反应 (DDR) 中 淋巴细胞发育。 2. 在淋巴细胞和皮肤细胞分化过程中调节序列特异性转录因子与 DNA 的接触。 3.在活性氧(ROS)和辐射诱导的DDR中。因此，2A-DUB/Mysm1 引起的 H2A 去泛素化可能参与调节对自身免疫、淋巴瘤和癌症的保护。由于 2A-DUB/Mysm1 工程缺陷小鼠（Mysm1 KO 小鼠）在 T 细胞和皮肤发育方面存在许多缺陷，包括严重的胸腺发育不全以及外周 T 细胞激活的改变、皮肤萎缩和过早衰老，因此我们在此建议利用遗传、免疫学和 分子生物学方法。根据申请人的初步数据，确定 Ink4/ARF 途径是 Mysm1 缺陷的胸腺细胞和表皮细胞中细胞凋亡增加和增殖率降低的潜在介质，2A-DUB/Mysm1 与 p19ARF/Ink4a 启动子的相互作用将在我们新生成的 p53-/-Mysm1-/- 和 Cdkn2a/ARF-/- Mysm1-/- 双 KO (DKO) 小鼠。将在 Lck-Cre x Mysm1flox/flox 小鼠以及 p53-/-Mysm1-/- DKO 和 H-Y TCR 转基因小鼠中探讨 Mysm1 组蛋白 H2A 去泛素化在胸腺细胞发育和选择中的作用。 T 细胞和皮肤细胞群中 Mysm1 的其他分子相互作用和结合伙伴将通过基于 ChIP 的方法进行验证。最终，Mysm1 缺陷导致的 T 细胞库潜在改变或 T 细胞和皮肤细胞遗传不稳定性的影响将通过转化方法在自身免疫和肿瘤模型中进行探索。这项研究旨在更好地了解表观遗传学机制如何与谱系特异性 TF 和分化程序相互作用以调节 T 细胞和皮肤发育，以及表观遗传学如何有助于预防自身免疫和癌症。