Understanding CTCF boundaries controlling Hox gene expression

了解控制 Hox 基因表达的 CTCF 边界

• 批准号: 9886295
• 负责人: Esteban Orlando Mazzoni
• 金额: $ 47.77万
• 依托单位: NEW YORK UNIVERSITY SCHOOL OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-03-15 至 2023-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9886295
• 关键词: 3-Dimensional; Affect; Binding; Body Patterning; Cell Differentiation process; Cells; Chromatin; Chromatin Structure; Chromosome Structures; Complement; Development; Developmental Biology; Embryonic Development; Enhancers; Ensure; Gene Activation; Gene Expression; Gene Expression Regulation; Genes; Genome; Genomics; Homeobox Genes; In Vitro; Individual; Inherited; Light; Mediating; Molecular; Motor Neurons; Mus; Nucleic Acid Regulatory Sequences; Organism; Pattern; Positioning Attribute; Proteins; Proteomics; Published Comment; RNA; Regulator Genes; Site; Spinal; Spinal Cord; System; Transcription Initiation Site; Transcriptional Regulation; cohesin; experience; experimental study; functional genomics; in vivo; interest; loss of function; motor control; mutant; novel; transcription factor

Understanding CTCF boundaries controlling Hox gene expression Summary Spatial and temporal control of gene expression is crucial for the development of multicellular organisms. Although changes in looping interactions between enhancers and transcription start sites is an acknowledged mode of gene regulation, the contribution of larger 3D genomic reorganizations to gene expression and normal development is largely obscure. We propose experiments to clarify how the CTCF transcription factor controls chromatin structure at the Hox clusters to ensure proper Hox gene expression and thus, body patterning. During embryonic development, precise expression of Hox genes instructs cells to recognize their relative position in body axes. Hox genes are organized in four clusters with individual genes in these clusters expressed in patterns that are spatially and temporally collinear with their physical chromosomal organization. Collinear Hox gene expression along the spinal cord controls motor neuron (MN) subtypes and thus their connectivity. During MN differentiation, the Hox clusters undergo a chromatin and 3-D reorganization from a single repressed state to two domains harboring either transcribed or repressed genes. The two chromatin states are insulated by CTCF binding at the boundary, maintaining stable Hox chromatin states inherited though development to ensure proper MN connectivity. Of relevance, we recently demonstrated that the CTCF boundary is essential to normal body patterning during embryonic development in vivo. To understand how CTCF maintains insulated chromatin and 3-D boundaries at Hox clusters we propose: 1) To understand how disrupting the CTCF-mediated chromatin boundary affects subtype identity of spinal MNs; 2) To determine the molecular basis of establishing a CTCF-dependent boundary; 3) An advanced proteomics study to identify factors required by chromatin associated CTCF for its insulator activity, emphasizing those whose interaction is RNA-dependent.

了解控制HOX基因表达的CTCF边界 概括 基因表达的空间和时间控制对于多细胞的发展至关重要 有机体。尽管增强器与转录开始之间的循环相互作用的变化 位点是一种公认​​的基因调节模式，是较大3D基因组的贡献 对基因表达和正常发育的重组在很大程度上是晦涩的。我们建议 实验以阐明CTCF转录因子如何控制HOX的染色质结构 簇以确保适当的HOX基因表达，从而确保身体模式。 在胚胎发育期间，HOX基因的精确表达指示细胞识别 它们在身体轴上的相对位置。 HOX基因在独立的四个群集中组织 这些簇中的基因以空间和时间共线的模式表达 他们的身体染色体组织。沿着脊髓的孔线HOX基因表达 控制运动神经元（MN）亚型，从而控制其连通性。在Mn分化过程中， HOX簇经历染色质和3-D重组从单个压抑状态到两个 带有转录或抑制基因的域。两个染色质状态是 由CTCF结合在边界处绝缘，维持稳定的HOX染色质状态遗传 尽管开发以确保适当的MN连接。相关性，我们最近证明了 CTCF边界对于胚胎发育过程中的正常身体图案至关重要 体内。了解CTCF如何在HOX处保持隔热染色质和3-D边界 我们建议的集群：1）了解CTCF介导的染色质边界的破坏 影响脊髓MN的亚型身份； 2）确定建立A的分子基础 CTCF依赖性边界； 3）一项先进的蛋白质组学研究，以确定由 染色质相关的CTCF用于其绝缘体活性，强调了那些相互作用的CTCF RNA依赖性。