The biochemical mechanism of Wnt signaling

Wnt信号的生化机制

• 批准号: 7171930
• 负责人: BERNADETTE C HOLDENER
• 金额: $ 22.23万
• 依托单位: STATE UNIVERSITY NEW YORK STONY BROOK
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-03-01 至 2009-08-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7171930
• 关键词: Affect; Affinity; Animals; Binding; Biochemical; Biological; Biological Assay; Cancer Etiology; Cell Surface Receptors; Cells; Defect; Development; Diagnosis; Dimerization; Disease; Disruption; Family; Family member; In Vitro; Individual; Investigation; Knowledge; LDL-Receptor Related Protein 1; Lead; Ligand Binding Domain; Ligands; Lipoprotein Receptor; Low Density Lipoprotein Receptor; Malignant Neoplasms; Measures; Mediating; Mutagenesis; Mutation; Numbers; Organ; Organism; Paracrine Communication; Pathway interactions; Pattern; Play; Preparation; Prevention approach; Property; Protein Family; Proteins; Receptor Activation; Relative (related person); Research Personnel; Role; Signal Pathway; Signal Transduction; Signaling Molecule; Specificity; Structure; System; Testing; Thinking; Tissues; Wnt proteins; base; improved; in vivo; insight; member; programs; protein purification; receptor; transmission process

DESCRIPTION (provided by applicant): The long-term objective of this proposal is to understand the mechanisms by which Wnt signals are transmitted in a controlled manner and how disruption of this mechanism leads to developmental defects and cancers. The Wnt family of secreted signaling molecules plays pivotal roles in the differentiation and patterning of various tissues during animal development. Aberrant activation of Wnt signaling also causes several cancers. Transmission of Wnt signals is mediated by two cell surface receptors, one from the Frizzled family and the other from the low-density lipoprotein receptor-related protein (LRP) family. It is, however, unclear how Wnt binding leads to the activation of the receptors and how the receptors transmit the Wnt signal downstream. This proposal will evaluate the hypothesis that receptor clustering induced by Wnt binding activates the downstream signal transmission. To establish the mechanisms of Wnt receptor activation, the investigations proposed here will employ biochemical and cell biological approaches to examine how receptors interact with each other and with downstream components in the presence or absence of Wnts. Since both the Wnt and Frizzled families consist of a large number of family members, it remains unclear how individual Wnts achieve specific interactions with various Frizzled proteins. Although differing affinities among various ligand-receptor pairs are thought to play deciding roles in establishing the specificities, this assumption has been difficult to test due to the lack of suitable Wnt preparations. To evaluate this hypothesis, this proposal will directly measure the specificities and affinities of Wnt-Frizzled interactions by employing soluble and active Wnt preparations that have become available recently. Since a fundamental knowledge of the biochemical properties of Wnts is essential to the elucidation of the signaling mechanism, this proposal will also determine the structural and biochemical features of Wnts important for their activities through mutagenesis, protein purification and biochemical characterization. A complete understanding of this signaling pathway will provide important insights for the development of highly selective, mechanism-based approaches for the prevention, diagnosis, and treatment of diseases and cancers caused by aberrant Wnt functions.

描述（由申请人提供）：该提案的长期目标是了解以受控方式传输Wnt信号的机制，以及该机制的破坏如何导致发育缺陷和癌症。分泌信号分子的Wnt家族在动物发育过程中在各种组织的分化和模式中扮演着关键的作用。 Wnt信号的异常激活也会引起几种癌症。 Wnt信号的传播是由两个细胞表面受体介导的，一个来自毛躁的家族，另一个来自低密度脂蛋白受体相关蛋白（LRP）家族。但是，尚不清楚Wnt结合如何导致受体的激活以及受体如何在下游传输Wnt信号。该建议将评估以下假设：Wnt结合引起的受体聚类激活下游信号传递。为了建立Wnt受体激活的机制，此处提出的研究将采用生化和细胞生物学方法来检查受体在存在或不存在WNT的情况下如何相互相互作用以及与下游成分相互作用。由于Wnt和毛躁的家庭都由大量家庭成员组成，因此尚不清楚单个Wnt如何与各种卷曲蛋白质实现特定相互作用。尽管人们认为各种配体受体对之间的亲密关系不同，在确定特异性方面起着决定作用，但由于缺乏合适的WNT准备工作，这种假设很难测试。为了评估这一假设，该提案将通过采用最近可用的可溶性和主动的Wnt制剂来直接衡量Wnt-Frizzled相互作用的特异性和亲和力。由于WNT的生化特性的基本知识对于阐明信号传导机制至关重要，因此该建议还将通过诱变，蛋白质纯化和生化特性来确定WNT对其活性重要的结构和生化特征。对该信号通路的完整理解将为开发高度选择性，基于机制的方法提供重要见解，以预防，诊断和治疗由异常WNT功能引起的疾病和癌症。