Mechanisms of Epigenetic inheritance

表观遗传机制

• 批准号: 9067600
• 负责人: Zhiguo Zhang
• 金额: $ 83.1万
• 依托单位: COLUMBIA UNIVERSITY HEALTH SCIENCES
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-09-01 至 2021-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9067600
• 关键词: Amino Acid Sequence; Binding Proteins; Biochemical; Cell Cycle; Cell division; Cells; Chromatin; Chromatin Structure; Complex; Coupled; DNA; DNA Repair; DNA biosynthesis; DNA replication fork; Defect; Development; Epigenetic Process; Genes; Genetic; Genomic Instability; Genomic approach; Heterochromatin; Higher Order Chromatin Structure; Histone H3; Human; Inherited; Malignant Neoplasms; Mammalian Cell; Methods; Mitotic; Molecular; Monitor; Mutation; Nucleosomes; Peptide Sequence Determination; Play; Process; Proteins; RNA; Role; S Phase; Time; Yeasts; daughter cell; genome integrity; histone modification; insight; novel; public health relevance; transmission process

 DESCRIPTION (provided by applicant): How epigenetic states are inherited during S phase of the cell cycle is one of the most challenging questions in the chromatin and epigenetic fields. DNA replication-coupled nucleosome assembly plays an important role in epigenetic inheritance following DNA replication and DNA repair. Mutations of most, if not all, genes involved in replication-coupled nucleosome assembly result in defects in transcriptional silencing at heterochromatin and genome instability in both yeast and mammalian cells. We have been studying how nucleosomes are formed following DNA replication in yeast and human cells and have made multiple significant contributions to this process. However, how parental histone (H3-H4)2 tetramers are transferred to replicating DNA is still poorly understood, which hinders our understanding of transmission of epigenetic information into daughter cells. The major challenge to understanding parental histone (H3-H4)2 assembly is a lack of methods to track this process. Despite this challenge, we have developed the eSPAN (enrichment and Sequencing Protein- Associated Nascent DNA) method that can discern whether a protein binds to leading or lagging strands of DNA replication forks. This method enables us for the first time to monitor nucleosome assembly of both newly synthesized and parental histone (H3-H4)2 onto leading and lagging strands of DNA replication forks. In this proposal, we will elucidate molecular mechanisms whereby parental (H3-H4)2 are assembled into nucleosomes following DNA replication and how epigenetic marks are inherited during mitotic cell division in both yeast and human cells using a combination of genetic, biochemical and genomic approaches. Together, our studies should have a profound impact on the understanding of nucleosome assembly and epigenetic inheritance.

 描述（由申请人提供）：表观遗传状态如何在细胞周期的 S 期遗传是染色质和表观遗传领域最具挑战性的问题之一。 DNA 复制耦合核小体组装在 DNA 复制和 DNA 修复后的表观遗传中发挥着重要作用。大多数（如果不是全部）参与复制偶联核小体组装的基因的突变会导致异染色质转录沉默缺陷以及酵母和哺乳动物细胞中的基因组不稳定。我们一直在研究酵母和人类细胞中 DNA 复制后核小体是如何形成的，并为此过程做出了多项重大贡献。然而，亲本组蛋白 (H3-H4)2 四聚体如何转移至复制 DNA 仍知之甚少，这阻碍了我们对表观遗传信息传递至子细胞的理解。了解亲本组蛋白 (H3-H4)2 组装的主要挑战是缺乏跟踪该过程的方法。尽管面临这一挑战，我们还是开发了 eSPAN（蛋白质相关新生 DNA 富集和测序）方法，可以辨别蛋白质是否与 DNA 复制叉的前导链或滞后链结合。这种方法使我们首次能够监测新合成的和亲本组蛋白 (H3-H4)2 的核小体组装到 DNA 复制叉的前导链和滞后链上。在本提案中，我们将结合遗传、生化和基因组方法，阐明亲本 (H3-H4)2 在 DNA 复制后组装成核小体的分子机制，以及在酵母和人类细胞的有丝分裂细胞分裂过程中表观遗传标记如何遗传。总之，我们的研究将对核小体组装和表观遗传的理解产生深远的影响。