Molecular Mechanism of TET-mediated Gene Regulation

项目总结/摘要 DNA胞嘧啶甲基化是哺乳动物细胞中重要的表观遗传修饰。异常DNA甲基化 与基因失调和基因组不稳定有关，导致癌症和其他疾病。十- Eleven易位（泰特）是负责DNA去甲基化以确保DNA甲基化的必需酶家族。 正确维护甲基化。泰特酶将5-甲基胞嘧啶（5 mC）氧化成主要的5-甲基胞嘧啶。 羟甲基胞嘧啶（5 hmC），DNA去甲基化的中间体和潜在的表观遗传标记。 TET 2的生殖系缺陷与免疫缺陷和儿童癌症有关。值得注意的是，TET 2是 血液癌症中最常见的突变基因之一，证明了泰特在 多种生物过程。我们和其他人已经表明，泰特酶是细胞生长所必需的。 通过调节超级增强子和诱导谱系特异性基因的表达来促进分化。然而，在这方面， 泰特酶促进允许的染色质环境用于基因活化的机制 仍不清楚研究计划的长期目标是：（1）全面了解如何 泰特酶和5 hmC促进染色质可及性;（2）研究泰特和5 hmC之间的串扰， （3）理解表观基因组暂时扰动的后果。完成这些 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- 受泰特和DNA甲基化调控的元件。我们将开发新的动物模型来研究 急性和可逆的泰特缺乏和测序方法来定位多个DNA修饰， 染色质可接近性同时在单个DNA分子上。我们的研究将提供关键的机制 深入了解泰特和DNA修饰如何调节基因表达和细胞分化。我们的研究结果 将有可能确定与免疫缺陷和癌症有关的基因， 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.