ANALYSIS OF NEUROFIBROMATOSIS TYPE 1 GENE FUNCTION

1 型神经纤维瘤病基因功能分析

• 批准号: 6639521
• 负责人: ANDRE BERNARDS
• 金额: $ 34.2万
• 依托单位: MASSACHUSETTS GENERAL HOSPITAL
• 依托单位国家: 美国
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-09-23 至 2006-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6639521
• 关键词: Drosophilidae; biological signal transduction; cell growth regulation; cyclic AMP; gene expression; gene induction /repression; genetic mapping; microarray technology; neoplasm /cancer genetics; neurofibromatosis; neurogenetics; protein kinase A; protein protein interaction; protein sequence

This proposal is aimed at understanding the function of the gene that is mutated in the human disease Neurofibromatosis type1. The disease is characterized by a wide variety of pathological manifestations (e.g. tumors, pigmentation changes, behavioral abnormalities, growth defect) and the basis of many of these is not known. The prevailing view of NF1 function is that it is primarily a negative regulator of the Ras GTPase by acting as a GTPase activating protein (GAP) for Ras. To study the function of NF1 in vivo in an organism amenable to genetic manipulations, a highly conserved Drosophila homologue was cloned and characterized. Studies with the Drosophila NF1 homologue have failed to show evidence of altered Ras1-mediated signaling in NF1 mutants suggesting that the postulated role of NF1 as a Ras1 regulator ma either be redundant or less important in vivo. In contrast strong genetic interactions were observed between NF1 and genes encoding components of the cAMP/PKA signaling pathway. NF1 mutants show defects in growth and in synaptic transmission. The growth defect is rescued by a mutant protein that lacks GAP activity and appears to require a non cell autonomous function of NF1. The experiments described here are aimed at elucidating the apparently Ras1- independent functions of the NF1 gene and its role in regulating growth via a non cell autonomous mechanism. Specific Aim 1 is to provide a detailed description of how NF1 regulates growth in vivo. Included is an analysis of the interaction between NF1 and the cAMP/PKA pathway. Specific Aim 2 is to define the signaling pathways that mediate Ras-independent functions of NF1 in vivo by identifying domains in the NF1 protein that interact with other pathways. Specific Aim 3 is to identify genes that interact with NF1 in vivo. These will be identified either by a genetic screen for enhancers and suppressors of the pupal size phenotype of a hypomorphic NF1 allele or by using a microarray of cDNA clones and looking for significant alteration in gene expression in NF1 mutants. These studies will help us understand the normal function of the NF1 gene in vivo and will contribute to our understanding of the diverse manifestations of the disease process.

该提案旨在了解人类疾病神经纤维瘤病 1 型中突变基因的功能。该疾病的特点是具有多种病理表现（例如肿瘤、色素沉着变化、行为异常、生长缺陷），并且其中许多病理表现的基础尚不清楚。 对 NF1 功能的普遍看法是，它主要是 Ras GTP 酶的负调节因子，充当 Ras 的 GTP 酶激活蛋白 (GAP)。为了研究 NF1 在适合基因操作的生物体内的功能，克隆并表征了高度保守的果蝇同源物。 对果蝇 NF1 同源物的研究未能显示 NF1 突变体中 Ras1 介导的信号改变的证据，这表明 NF1 作为 Ras1 调节因子的假定作用在体内可能是多余的或不太重要。 相反，在 NF1 和编码 cAMP/PKA 信号通路成分的基因之间观察到强烈的遗传相互作用。 NF1 突变体在生长和突触传递方面表现出缺陷。这种生长缺陷被一种缺乏 GAP 活性的突变蛋白所拯救，并且似乎需要 NF1 的非细胞自主功能。这里描述的实验旨在阐明 NF1 基因明显独立于 Ras1 的功能及其通过非细胞自主机制调节生长的作用。具体目标 1 是提供 NF1 如何调节体内生长的详细描述。 其中包括 NF1 和 cAMP/PKA 通路之间相互作用的分析。 具体目标 2 是通过识别 NF1 蛋白中与其他途径相互作用的结构域来定义介导 NF1 体内 Ras 独立功能的信号传导途径。 具体目标 3 是鉴定体内与 NF1 相互作用的基因。 这些可以通过对亚等位基因的蛹大小表型的增强子和抑制子进行遗传筛选来鉴定，或者通过使用cDNA克隆微阵列并寻找NF1突变体中基因表达的显着改变来鉴定。这些研究将帮助我们了解 NF1 基因在体内的正常功能，并将有助于我们了解疾病过程的各种表现。