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（由适用提供）：在细胞周期的S阶段，表观遗传状态如何遗传是染色质和表观遗传场中最挑战的问题之一。 DNA复制耦合核小体组装在DNA复制和DNA修复后在表观遗传遗传中起重要作用。大多数（如果不是全部）与复制耦合核小体组装的基因的突变导致酵母和酵母细胞中异染色质和基因组不稳定性的转录沉默缺陷。我们一直在研究酵母和人类细胞中DNA复制后如何形成核小体，并为此过程做出了多种重要贡献。然而，父母组蛋白（H3-H4）2四聚体如何转移到复制DNA仍然知之甚少，这阻碍了我们对表观遗传信息传播到子细胞中的理解。了解父母组蛋白（H3-H4）2组件的主要挑战是缺乏跟踪此过程的方法。尽管有这一挑战，但我们还是开发了ESPAN（富集和测序蛋白与蛋白质相关的新生DNA）方法，该方法可以辨别蛋白是与DNA复制叉的前导或滞后链结合的。这种方法使我们首次可以监测新合成和父母组蛋白（H3-H4）2的核小体组装到DNA复制叉的前导和滞后链上。在此提案中，我们将阐明分子机制，在DNA复制后将父母（H3-H4）2组装成核小体中，以及如何使用遗传，生物化学和基因组方法的组合在酵母和人类细胞中的有丝分裂细胞分裂期间遗传表观遗传标记。总之，我们的研究应该对理解核磁体和表观遗传遗传产生深远的影响。