Molecular Mechanism of TET-mediated Gene Regulation

项目摘要/摘要 DNA胞嘧啶甲基化是哺乳动物细胞的一种中心性表观遗传修饰。DNA甲基化异常 与基因失调和基因组不稳定有关，导致癌症和其他疾病。十个- 11易位(Tet)是负责DNA去甲基化的关键酶家族，以确保 适当地维护甲基组。Tet酶将5-甲基胞嘧啶(5mC)氧化成主要的5-甲基胞嘧啶 羟甲基胞嘧啶(5hmC)，DNA去甲基化的中间体，也是潜在的表观遗传标记。 TET2的生殖系缺陷与免疫缺陷和儿童癌症有关。值得注意的是，TET2是 血液学癌症中最常见的突变基因之一，证明了Tet在 多个生物过程。我们和其他人已经证明了Tet酶对细胞是必不可少的 通过调节超级增强子和诱导谱系特异性基因的表达而发生分化。然而， Tet酶促进基因激活的染色质环境的机制 目前仍不清楚。研究计划的长期目标是：(1)全面了解 Tet酶和5HmC促进染色质的可及性；(2)研究Tet和5HmC之间的串扰 组蛋白；(3)了解表观基因组暂时扰动的后果。要实现这些目标 目标，我们将使用精确的表观基因组编辑来操纵和监测顺式基因的表观遗传修饰。 受Tet和DNA甲基化调节的元件。我们将开发新的动物模型来研究 急性和可逆性Tet缺乏症和测序方法 染色质在单个DNA分子上同时可及。我们的研究将提供关键的机制 洞察Tet和DNA修饰如何调节基因表达和细胞分化。我们的发现 将可能识别与免疫缺陷和癌症有关的基因，提供一个发展的机会 有针对性的治疗。

PROJECT SUMMARY/ABSTRACT DNA cytosine methylation is a central epigenetic modification in mammalian cells. Aberrant DNA methylation has been linked to gene dysregulation and genomic instability, resulting in cancer and other diseases. Ten- Eleven Translocation (TET) is the essential enzyme family responsible for DNA demethylation to ensure the proper maintenance of the methylome. TET enzymes oxidize 5-methylcytosines (5mC) into mainly 5- hydroxymethylcytosine (5hmC), an intermediate for DNA demethylation and a potential epigenetic mark. Germline deficiency of TET2 is associated with immunodeficiency and childhood cancers. Notably, TET2 is one of the most frequently mutated genes in hematological cancers, demonstrating the importance of TET in multiple biological processes. We and others have shown that TET enzymes are essential for cell differentiation by regulating super-enhancers and inducing the expression of lineage-specific genes. However, the mechanism by which TET enzymes facilitate the permissive chromatin environment for gene activation remains unclear. The long-term goals of the research program are: (1) to comprehensively understand how TET enzymes and 5hmC promote chromatin accessibility; (2) to investigate the crosstalk between TET and histones; (3) to understand the consequences of temporary perturbation of epigenome. To accomplish these goals, we will use precision epigenome editing to manipulate and monitor epigenetic modifications of cis- elements regulated by TET and DNA methylation. We will develop novel animal models to study the impact of acute and reversible TET deficiency and a sequencing method to map multiple DNA modifications and chromatin accessibility simultaneously on a single DNA molecule. Our research will provide crucial mechanistic insights into how TET and DNA modifications regulate gene expression and cell differentiation. Our findings will potentially identify genes involved in immunodeficiency and cancer, providing an opportunity to develop targeted treatments.