Dominant Mutation that Affect EGF-R Signal Transduction

影响 EGF-R 信号转导的显性突变

• 批准号: 6387314
• 负责人: Douglas M Ruden
• 金额: $ 14.66万
• 依托单位: UNIVERSITY OF ALABAMA AT BIRMINGHAM
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-09-01 至 2004-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6387314
• 关键词: Drosophilidae; autosomal dominant trait; biological signal transduction; epidermal growth factor; fertility; gene mutation; genetic screening; growth factor receptors; molecular cloning

DESCRIPTION (adapted from investigator's abstract): The long-range goal of this proposal is to understand how the Epidermal Growth Factor Receptor (EGF-R) is controlled during metazoan development. Recessive loss-of-function mutations in many general components of receptor tyrosine kinase (RTK) signal transduction pathways, such as Sos, Ras, Raf, and MAPK, have been identified in previous screens for dosage-sensitive suppressors and enhancers of RTK signaling mutations. While the previous screens are useful in identifying mutations in many RTK signaling genes, they might have missed components that are present redundantly or in non-limiting amounts. Also, the previous screens generally isolated loss-of-function alleles of signaling genes, whereas the epistatic relationships among these genes has been determined primarily through the isolation and characterization of dominant mutations. Dominant mutations in genes have also been extensively used to analyze signaling pathways in the less genetically tractable vertebrate tissue culture systems. The investigators propose a novel genetic screen which will allow the isolation of dominant gain-of-function and dominant loss-of function mutations in genes involved in EGF-R and other signal transduction pathways. Genes that either inhibit or activate EGFR signaling will be identified by isolating dominant female sterile (DFS) mutations that disrupt the differentiation or proliferation of the follicle cells that surround the egg chambers. The genetic screen involves using newly developed techniques to recover mutations from mosaic animals. Preliminary genetic screens have already identified DFS mutations in two genes, Star-Kojak and Ugra-DFS. Both of these DFS mutations generate their phenotypes by down-regulating EGF-R signaling in the follicle cells that surround the oocyte. Loss-of-function alleles of Star and Ugra have phenotypes that suggest that they might be involved in the poorly understood area of ligand production and presentation. Since other signal transduction pathways' such as those that involve wingless, Notch, TGFb and hedgehog, are also involved in follicle cell development, a further advantage of the proposed screen is that follicle-cell dependent DFS mutations that affect these other pathways could also be isolated. In order to accomplish their goal of understanding EGF-R regulation. three objectives are paramount. Firstly, they will conduct additional .genetic screens to isolate dominant mutations, like Star-Kojak and Ugra-DFS, in other genes involved in EGF-R and other signal transduction pathways. Secondly, molecular analysis of Ugra will be performed to learn what it encodes and what role it plays in EGF-R signaling. Thirdly, they will perform a detailed molecular and phenotypic analysis of Star-Kojak and Star loss-of-function alleles to better understand the role of Star in EGF-R signal transduction. It is important to understand regulators of RTK signaling because Ras-Raf dependent neoplasia accounts for as many as one-fifth of all human cancers.

描述（改编自研究者摘要）：本研究的长期目标 建议是了解表皮生长因子受体（EGF-R）是如何被激活的。 在后生动物发育过程中受到控制。隐性功能丧失突变 受体酪氨酸激酶（RTK）信号转导的许多一般组分 在以前的研究中已经鉴定了Sos、Ras、Raf和MAPK等通路， 筛选RTK信号传导的剂量敏感性抑制剂和增强剂 突变。虽然先前的筛选在鉴定突变中是有用的， 许多RTK信号基因，他们可能已经错过了组件， 冗余地或以非限制性的量。此外，以前的屏幕通常 孤立的信号基因功能丧失等位基因，而上位性 这些基因之间的关系主要是通过 显性突变的分离和表征。显性突变 基因也被广泛用于分析信号通路， 遗传上易处理的脊椎动物组织培养系统。调查人员 提出了一种新的遗传筛选方法， 基因的功能获得和显性功能丧失突变， EGF-R和其他信号转导途径。抑制或 激活EGFR信号传导将通过分离显性雌性不育 (DFS)突变，破坏细胞的分化或增殖， 围绕卵腔的卵泡细胞。基因筛查包括 利用新开发的技术从嵌合体动物身上恢复突变。 初步的遗传筛查已经在两个基因中发现了DFS突变， Star-Kojak和Ugra-DFS。这两种DFS突变都产生了它们的表型 通过下调卵泡周围细胞的EGF-R信号， 卵母细胞星星和Ugra的功能丧失等位基因的表型表明 它们可能参与了人们知之甚少的配体生产领域， 和介绍。由于其他信号传导途径，如那些 涉及无翅、Notch、TGF β和hedgehog，也涉及滤泡细胞 发展，提出的筛选的另一个优点是， 影响这些其他途径的依赖性DFS突变也可能是 与世隔绝为了实现他们理解EGF-R调节的目标。 有三个目标至关重要。首先，他们将进行额外的.遗传 筛选分离显性突变，如Star-Kojak和Ugra-DFS，在其他 参与EGF-R和其他信号转导途径的基因。第二、 将对Ugra进行分子分析，以了解它编码什么， 它在EGF-R信号传导中起作用。第三，他们将进行详细的 Star-Kojak和星星功能丧失的分子和表型分析 等位基因，以更好地理解星星在EGF-R信号转导中的作用。它 了解RTK信号的调节器很重要，因为Ras-Raf 依赖性瘤形成占所有人类癌症的五分之一。