Molecular Genetics of Segment Identity

片段同一性的分子遗传学

• 批准号: 7473438
• 负责人: RICHARD S MANN
• 金额: $ 35.19万
• 依托单位: COLUMBIA UNIVERSITY HEALTH SCIENCES
• 依托单位国家: 美国
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-08-01 至 2012-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7473438
• 关键词: Abdomen; Animals; Anterior; Base Pairing; Binding Sites; Biochemistry; Biological; Biological Assay; Biological Models; Biology; Cell Maintenance; Cell Proliferation; Complex; Congenital Abnormality; DNA; DNA Binding; DNA Structure; DNA-Protein Interaction; Development; Disease; Drosophila genus; Drosophila inturned protein; Drosophila melanogaster; Equilibrium; Family; Funding; Gene Expression Regulation; Gene Targeting; Genes; Genetic; Goals; Homeodomain Proteins; Human; In Vitro; Limb structure; Malignant Neoplasms; Maps; Mediating; Minor Groove; Modeling; Molecular Genetics; Morphology; Motor Neurons; Numbers; Organ; Organogenesis; Orthologous Gene; Pathway interactions; Pattern; Play; Protein Binding; Proteins; Public Health; Publishing; Reading; Recruitment Activity; Regulation; Regulatory Element; Resolution; Role; Signal Pathway; Specificity; Stem cells; System; Testing; Vertebrates; Wing; Work; X-Ray Crystallography; appendage; base; cofactor; design; fascinate; homeodomain; in vivo; interest; leukemia; malformation; morphogens; novel; paralogous gene; research study; size; three dimensional structure; tool; transcription factor; unpublished works

DESCRIPTION (provided by applicant): The Hox family of transcriptional regulators are homeodomain proteins that play important roles in many aspects of animal development and disease. For these proteins to perform their functions, they need to achieve the correct functional specificities in vivo. Using the fruit fly, Drosophila melanogaster, as the model system, this project builds on earlier work to better understand how these transcriptional regulators function in vivo. In previous work, results were obtained suggesting that Hox proteins, in conjunction with cofactors of the Extradenticle (Exd, Pbx in vertebrates) and Homothorax (Hth; Meis in vertebrates) families, achieve DNA binding specificity by reading a sequence-dependent DNA structure using residues in their homeodomains and nearby linker regions. A second set of findings demonstrated that some Hox proteins interact with these cofactors via multiple, partially redundant interaction motifs. Third, results were obtained showing that one Hox protein in Drosophila, Ultrabithorax (Ubx), modifies appendage morphologies, in particular, appendage size, by altering the levels and mobilities of diffusible morphogens such as Decapentaplegic (Dpp). Ubx executes these modfications in part by transcriptionally regulating two genes, master of thickveins (mtv) and dally in the developing appendage. Building on these results, the aims of this project are to 1) extend and generalize the Exd-dependent Hox specificity model, 2) determine the role of multiple Exd interaction motifs that are present in some Hox proteins, and 3) determine which of the targets identified previously in the control of appendage morphology by Ubx are directly regulated by this Hox protein. The approaches for all of these aims rely heavily on using a combination of Drosophila genetic tools and in vitro protein-DNA interaction assays. X-ray crystallography, to determine the three dimensional structures of some Hox-Exd-DNA ternary complexes, will also be employed. Public Health Relevance: Although first analyzed in the context of anterior-posterior patterning, there are a wealth of critical functions in animal development from motor neuron specification to organogenesis to stem cell maintenance that are now appreciated to be controlled by Hox genes. Equally important and well studied are the roles that Hox genes and their cofactors play in human birth defects, such as limb malformations, and some cancers, such as leukemia. Thus, a mechanistic understanding of how these transcription factors regulate their target genes will impact our understanding of many aspects of developmental and disease biology.

描述（由申请人提供）： Hox 转录调节因子家族是同源域蛋白，在动物发育和疾病的许多方面发挥着重要作用。为了使这些蛋白质发挥其功能，它们需要在体内实现正确的功能特异性。该项目使用果蝇（果蝇）作为模型系统，以早期工作为基础，以更好地了解这些转录调节因子在体内的功能。在之前的工作中，获得的结果表明，Hox 蛋白与 Extradenticle（脊椎动物中的 Exd、Pbx）和 Homothorax（脊椎动物中的 Hth；Meis）家族的辅因子结合，通过使用其同源域和附近接头区域中的残基读取序列依赖性 DNA 结构来实现 DNA 结合特异性。第二组发现表明，一些 Hox 蛋白通过多个部分冗余的相互作用基序与这些辅因子相互作用。第三，获得的结果表明，果蝇 Ultrabithorax (Ubx) 中的一种 Hox 蛋白通过改变可扩散形态发生素 (例如 Decapentaplegic (Dpp)) 的水平和迁移率来改变附肢形态，特别是附肢大小。 Ubx 部分通过转录调节两个基因来执行这些修饰，即发育中附属物中的 master ofthickveins (mtv) 和 dally。基于这些结果，该项目的目标是 1) 扩展和推广 Exd 依赖性 Hox 特异性模型，2) 确定一些 Hox 蛋白中存在的多个 Exd 相互作用基序的作用，3) 确定之前确定的 Ubx 控制附属物形态的靶标中哪些是由该 Hox 蛋白直接调节的。所有这些目标的方法在很大程度上依赖于果蝇遗传工具和体外蛋白质-DNA 相互作用测定的结合。还将采用 X 射线晶体学来确定一些 Hox-Exd-DNA 三元复合物的三维结构。 公共健康相关性：虽然首先是在前后模式的背景下进行分析，但动物发育中从运动神经元规范到器官发生再到干细胞维持等许多关键功能现在被认为是由 Hox 基因控制的。同样重要且经过充分研究的是 Hox 基因及其辅助因子在人类出生缺陷（例如肢体畸形）和某些癌症（例如白血病）中所发挥的作用。因此，对这些转录因子如何调节其靶基因的机制理解将影响我们对发育和疾病生物学许多方面的理解。