The molecular mechanism of Aire

艾尔的分子机制

• 批准号: 9382331
• 负责人: DIANE J MATHIS
• 金额: $ 42.38万
• 依托单位: HARVARD MEDICAL SCHOOL
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-12-10 至 2022-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9382331
• 关键词: ATAC-seq; Address; Antigens; Autoimmune Diseases; Autoimmunity; Binding; Binding Sites; Biochemical; Cells; ChIP-seq; Chromatin; Chromatin Loop; Collaborations; DNA Methylation; Data; Data Set; Dimensions; Disease; Elements; Enhancers; Epithelial Cells; Fibrinogen; Funding; Genes; Genetic Polymorphism; Genetic Transcription; Goals; Histones; Individual; Insulin-Dependent Diabetes Mellitus; Knock-out; Maps; Mediator of activation protein; Modus; Molecular; Multiprotein Complexes; Mus; Mutate; Myasthenia Gravis; Pathway interactions; Patients; Peripheral; Pernicious Anemia; Proteins; RNA Polymerase II; Series; Site; Stretching; T-Lymphocyte; Technology; Therapeutic; Thymus Gland; Tissues; Transcript; Transcription Initiation; Vitiligo; cell type; central tolerance; cohesin; congenital immunodeficiency; experimental study; knock-down; mutant; promoter; transcription factor; whole genome

Aire regulates central T cell tolerance by controlling thymic medullary epithelial cell (MEC) expression of a battery of transcripts encoding peripheral-tissue antigens. From early on, Aire was recognized to be a transcriptional regulator, but it soon became apparent that it does not operate like a conventional transcription factor, i.e. binding to promoters and inducing initiation of transcription. Studies completed during the last funding-cycle demonstrated that Aire-induced genes occur as intra- or inter-chromosomal clusters within individual cells, that Aire participates in multiple multi-protein complexes, and that it preferentially localizes to and activates so-called “super-enhancers.” Super-enhancers (a.k.a “stretch” or “serial” enhancers) are extended regions of chromatin that are over-loaded with general and cell-type-specific transcription factors, and are thought to serve as depots for coordinate and efficient delivery of these factors to targeted promoters via chromatin looping. In addition, preliminary data documented herein indicate that Aire associates, directly or indirectly, with cohesin, one of the major orchestrators of long-range chromatin interactions (in collaboration with CTCF and/or mediator). Thus, the overall goal of this proposed project is to determine how Aire integrates into the three-dimensional organization of chromatin. This goal will be addressed via three Specific Aims: ● To determine whether Aire associates with proteins known to orchestrate 3D chromatin interactions: CTCF, cohesin, NIPBL and mediator. Experiments under this Aim will employ primarily biochemical approaches to determine whether Aire associates with the three major 3D-chromatin-organizing elements (and a cohesin-loader, NIPBL). ● To integrate Aire’s distribution along MEC chromatin with those of CTCF, cohesin and mediator; to determine how Aire impacts CTCF/cohesin/mediator placement and, vice versa, how cohesin influences Aire’s placement. This series of experiments will exploit recent improvements in ChIP-seq (and other whole-genome) technologies to map the binding sites of the three chromatin organizers in relation to Aire binding and other landmarks – in wild-type, Aire-knockout and inducible Smc1-knockdown mice ● To define the relationship between Aire and three-dimensional chromatin organization. This set of experiments will use HiC technology to generate whole-genome interaction maps for MEC chromatin from Aire+/+ and Aire-/- mice. Successful completion of these studies will bring our understanding of Aire control of T cell tolerance to a new level of molecular understanding, and is likely to resolve several of the outstanding conundrums related to Aire function. The Aire story continues to intrigue!

Aire 通过控制胸腺髓质上皮细胞 (MEC) 的表达来调节中枢 T 细胞耐受性 从很早开始，艾尔就被认为是编码外周组织抗原的转录本。 转录调节因子，但很快就发现它的运作方式与传统转录不同 因子，即与启动子结合并诱导转录起始的研究在最后完成。 资助周期表明，艾尔诱导的基因以染色体内或染色体间簇的形式出现 单个细胞，Aire 参与多个多蛋白复合物，并且优先定位于 并激活所谓的“超级增强器”。超级增强器（又名“拉伸”或“串行”增强器）是 染色质的延伸区域超载了一般和细胞类型特异性转录因子， 并被认为是协调和有效地将这些因子传递给目标启动子的仓库 此外，本文记录的初步数据表明 Aire 直接或相关。 间接地，与粘连蛋白，长程染色质相互作用的主要协调者之一（合作 因此，该项目的总体目标是确定 Aire 的集成方式。 染色质的三维组织这一目标将通过三个具体目标来实现： ● 为了确定 Aire 是否与已知可协调 3D 染色质相互作用的蛋白质相关： CTCF、粘连蛋白、NIPBL 和介体将主要采用生化。 确定 Aire 是否与三个主要 3D 染色质组织元件（以及 粘连蛋白装载机，NIPBL）。 ● 将Aire沿MEC染色质的分布与CTCF、粘连蛋白和介体的分布整合起来； 确定 Aire 如何影响 CTCF/粘连蛋白/介体的放置，反之亦然，粘连蛋白如何影响 影响 Aire 的布局 这一系列实验将利用 ChIP-seq 的最新改进（以及 其他全基因组）技术来绘制与 Aire 相关的三个染色质组织者的结合位点 结合和其他标志物 – 在野生型、Aire 敲除小鼠和可诱导的 Smc1 敲除小鼠中 ● 定义Aire 与三维染色质组织之间的关系。 实验将使用 HiC 技术生成 MEC 染色质的全基因组相互作用图谱 Aire+/+ 和 Aire-/- 小鼠。 这些研究的成功完成将使我们对艾尔控制 T 细胞耐受性的理解更加深入。 分子理解的新水平，并可能解决与 艾尔功能。艾尔的故事继续令人着迷！