Repression via Facultative Heterochomatin.

通过兼性异染色质进行抑制。

• 批准号: 8438415
• 负责人: DANNY REINBERG
• 金额: $ 31.87万
• 依托单位: NEW YORK UNIVERSITY SCHOOL OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-01-01 至 2014-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8438415
• 关键词: Accounting; Affect; Antibodies; Architecture; Binding; Biochemical; Catalysis; Cell Cycle; Cell Cycle Progression; Cell Cycle Proteins; Cell Differentiation process; Cell Lineage; Cell Nucleus; Cell division; Cell physiology; Cells; Chromatin; Chromatin Structure; Cleaved cell; Complex; DLEC1 gene; DNA Binding; DNA Damage; DNA Sequence; DNA biosynthesis; Degradation Pathway; Detection; Deubiquitinating Enzyme; Development; Disease; EZH2 gene; Electron Microscopy; Enzymes; Epigenetic Process; Family; Family member; Fluorescence Microscopy; Functional RNA; Gene Expression; Gene Expression Profile; Gene Targeting; Genes; Genetic Transcription; Genome; Goals; Heterochromatin; Histone H3; Histones; Homologous Gene; In Vitro; Label; Ligase; Link; Lysine; Maintenance; Malignant Neoplasms; Malignant neoplasm of prostate; Mass Spectrum Analysis; Methylation; Methyltransferase; Mitochondria; Modification; Molecular; Mus; Nuclear; Nucleosomes; Organ; Organism; Phase; Phosphorylation; Phosphorylation Site; Polycomb; Polyubiquitin; Post-Translational Protein Processing; Post-Translational Regulation; Process; Property; Proteasome Inhibitor; Protein Family; Proteins; Quantum Dots; Reader; Regulation; Reporting; Repression; Resolution; Role; Signal Transduction; Sister; Site; Specificity; Spermatogenesis; Staging; Stress; Structure; System; Tail; Testing; Testis; Tissues; cancer cell; cancer cell differentiation; cell type; embryonic stem cell; fascinate; gel mobility shift assay; gene repression; histone methyltransferase; in vivo; indexing; innovation; member; metaplastic cell transformation; mouse model; novel; particle; protein complex; protein degradation; public health relevance; reconstitution; response; sperm cell; tumor progression; ubiquitin-protein ligase

DESCRIPTION (provided by applicant): The complexity of multi-cellular organisms characterized by cell specialization and sophisticated tissue and organ architecture is possible because of an efficient indexing system that keeps track of which sections of the genome are active or repressed, according to cell type and developmental phase. This "epigenetic" information (independent of DNA sequence) not only needs to be accurately established, but must also be transmitted to the cell's progeny. This must be achieved through a number of molecular mechanisms, many of which impact the structure of chromatin, particularly histones. Key to cell identity is the establishment and maintenance of "facultative heterochromatin", i.e. the silencing of specific genes in certain cell lineages through the formation of chromatin structure(s) repressive to transcription. The goal of this proposal is to expand our previous studies on the molecular mechanisms underlying facultative heterochromatin. How is selectivity achieved? What chromatin structures contain epigenetic information? How is this information transmitted through cell division? We will answer these and other questions through traditional and innovative biochemical approaches. In aim 1, we will expand our studies on PRC2, a central chromatin regulator on which we have accumulated much molecular information in the last years. We will study further: the function of EZH1, an EZH2 homolog with less pronounced methyltransferase activity; the effects of optional PRC2 complex subunits in cell differentiation and cancer; and the role of two novel EZH2 phosphorylation sites on PRC2 activity, chromatin localization, and interaction with non-coding RNAs (ncRNAs). In aim 2, we will employ TIRF microscopy and state-of-the-art mass spectrometry to determine whether sister histones within the same nucleosome carry any symmetrical post-translational modification, which would be strong candidates for "true" epigenetic marks as they may be equally segregated upon DNA replication. In aim 3, we will expand our studies on MBT proteins, an understudied family of chromatin binders; in particular we will investigate the biochemical and cellular function of SFMBTs and SCMH1/L2, which contain MBT repeats and were genetically classified as Polycomb group genes. The role of Pr-SET7 in preserving chromatin structure, protecting from or signaling DNA damage, its interaction with PCNA and its interaction with the cognate histone reader, L3MBTL1, will be investigated in aim 4, as well as the potential for this interaction to transmit epigenetic information. In aim 5, we will continue and expand our studies on SirT3, a fascinating Sirtuin with a dual role in mitochondrial function and regulation of nuclear transcription. We will explore this connection, as well as post-translational modifications and interactors of SirT3.

描述（由申请人提供）：以细胞特化和复杂的组织和器官结构为特征的多细胞生物体的复杂性是可能的，因为有效的索引系统可以根据细胞类型和发育阶段跟踪基因组的哪些部分是活跃的或受抑制的。这种“表观遗传”信息（独立于DNA序列）不仅需要准确建立，而且还必须传递给细胞的后代。这必须通过许多分子机制来实现，其中许多分子机制会影响染色质的结构，特别是组蛋白。细胞身份的关键是“兼性异染色质”的建立和维持，即通过形成抑制转录的染色质结构来沉默某些细胞谱系中的特定基因。该提案的目标是扩展我们之前对兼性异染色质分子机制的研究。选择性是如何实现的？哪些染色质结构包含表观遗传信息？这些信息是如何通过细胞分裂传递的？我们将通过传统和创新的生化方法回答这些问题和其他问题。在目标1中，我们将扩大对PRC2的研究，PRC2是一种中央染色质调节因子，我们在过去几年中积累了大量的分子信息。我们将进一步研究：EZH1（一种 EZH2 同源物，甲基转移酶活性不太明显）的功能；可选的 PRC2 复合体亚基在细胞分化和癌症中的作用；以及两个新的 EZH2 磷酸化位点对 PRC2 活性、染色质定位以及与非编码 RNA (ncRNA) 相互作用的作用。在目标 2 中，我们将采用 TIRF 显微镜和最先进的质谱法来确定同一核小体内的姐妹组蛋白是否携带任何对称的翻译后修饰，这将是“真正的”表观遗传标记的有力候选者，因为它们在 DNA 复制时可能被同等地分离。在目标 3 中，我们将扩大对 MBT 蛋白的研究，MBT 蛋白是一个尚未研究的染色质结合物家族；特别是，我们将研究 SFMBT 和 SCMH1/L2 的生化和细胞功能，它们含有 MBT 重复序列，在遗传学上被归类为 Polycomb 组基因。 Pr-SET7 在保护染色质结构、防止 DNA 损伤或向 DNA 损伤发出信号方面的作用、其与 PCNA 的相互作用以及其与同源组蛋白读取器 L3MBTL1 的相互作用，将在目标 4 中进行研究，以及这种相互作用传递表观遗传信息的潜力。在目标 5 中，我们将继续并扩展对 SirT3 的研究，这是一种令人着迷的 Sirtuin，在线粒体功能和核转录调节中具有双重作用。我们将探索这种联系，以及 SirT3 的翻译后修饰和相互作用。