Epigenetic modifications during hematopoiesis

造血过程中的表观遗传修饰

• 批准号: 7012361
• 负责人: Michael D Litt
• 金额: $ 20.57万
• 依托单位: BALL STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-07-01 至 2011-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7012361
• 关键词: DNA binding protein; DNA methylation; RNA interference; animal genetic material tag; binding sites; cell differentiation; chickens; chromatin immunoprecipitation; developmental genetics; epigenetics; functional /structural genomics; gene expression; genetic regulation; globin; hematopoiesis; heterochromatin; histones; intermolecular interaction; lysine; monoclonal antibody; transcription factor; transfection

DESCRIPTION (provided by applicant): All genetic processes within the nuclei of a eukaryotic cell occur in the context chromatin. Post-translational modifications of histones, the primary component of chromatin, are involved in the regulatory functions of chromatin. Histone methylation at specific lysines residues is associated with both the transcriptional stimulation and repression of genes. Methylation at two lysine sites on histone H3 (K9 and K27) are implicated in the formation of pericentric heterochromatin, X inactivation, Polycomb-mediated gene silencing, and transcriptional repression at euchromatin positions. All these function involve the formation of repressive chromatin. Two classes of proteins heterochromatin protein 1 (HP1) and the polycomb group complex (PcG) interact with histone H3 methylated at lysine 9 (H3-K9) and 27 (H3-K27). Data indicate that HP1 is specific for H3-K9 and PcG is specific for H3-K27. Both HP1 and PcG can establish and propagate repressive heterochromatin. In this proposal we examine the histone methylation at lysine 9 and 27, the HP1 and PcG proteins that interact with these modified histones, and a DMA regulatory region that modulates these interactions. To accomplish this, chromatin immunoprecipitations with antibodies specific to these proteins and histone modifications are performed across the chicken beta-globin neighborhood. Because this neighborhood is well characterized and developmentally regulated, it is an ideal model system to determine the role of these modifications in the regulatory functions of chromatin during cell differentiation.

描述（由申请人提供）：真核细胞核内的所有遗传过程都在染色质中发生。组蛋白的翻译后修饰（染色质的主要成分）参与了染色质的调节功能。特定赖氨酸残基的组蛋白甲基化与基因的转录刺激和抑制均相关。在组蛋白H3（K9和K27）上两个赖氨酸位点的甲基化与折内杂色异染色质，X灭活，多孔介导的基因沉默和在呼吸素位置的转录抑制有关。所有这些功能都涉及抑制染色质的形成。两类蛋白质异染色质蛋白1（HP1）和Polycomb组复合物（PCG）在赖氨酸9（H3-K9）和27（H3-K27）上与组蛋白H3甲基化相互作用。数据表明HP1特定于H3-K9，而PCG则针对H3-K27。 HP1和PCG都可以建立并传播抑制性异染色质。在该提案中，我们检查了赖氨酸9和27处的组蛋白甲基化，与这些改良的组蛋白相互作用的HP1和PCG蛋白以及调节这些相互作用的DMA调节区域。为此，在鸡β-珠蛋白邻域进行了针对这些蛋白质特异性抗体和组蛋白修饰的抗体的染色质免疫沉淀。由于该邻域的表征和发展受到调节，因此它是确定这些修饰在细胞分化过程中染色质调节功能中的作用的理想模型系统。