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.

该建议旨在理解在人类疾病神经纤维瘤病类型1中突变的基因的功能。该疾病的特征是多种病理表现（例如肿瘤，色素沉着变化，行为异常，生长缺陷），而其中许多的基础尚不清楚。 NF1函数的流行视图是，它主要是RAS GTPase的负调节剂，它通过充当RAS的GTPase激活蛋白（GAP）。为了研究NF1在可容纳遗传操作的生物体中体内的功能，克隆并表征了高度保守的果蝇同源物。 果蝇NF1同源物的研究未能显示出NF1突变体中RAS1介导的信号传导改变的证据，这表明NF1作为RAS1调节剂MA的假定作用是多余的，要么在体内重要。 相比之下，在NF1和编码CAMP/PKA信号通路的基因之间观察到了强遗传相互作用。 NF1突变体在生长和突触传播方面表现出缺陷。生长缺陷是由缺乏间隙活性的突变蛋白挽救的，似乎需要NF1的非细胞自主功能。此处描述的实验旨在阐明NF1基因的RAS1独立功能及其通过非细胞自主机制在调节生长中的作用。具体目标1是提供有关NF1如何调节体内生长的详细描述。 其中包括对NF1与CAMP/PKA途径之间的相互作用进行分析。 特定目的2是定义通过识别与其他途径相互作用的NF1蛋白中NF1在体内介导NF1非依赖性功能的信号传导途径。 特定目的3是鉴定与体内与NF1相互作用的基因。 这些将通过遗传筛选来鉴定出肌张力型NF1等位基因的bi尺尺寸表型的遗传筛选，或者通过使用cDNA克隆的微阵列并寻找NF1突变体中基因表达的显着改变。这些研究将有助于我们了解体内NF1基因的正常功能，并有助于我们理解疾病过程的各种表现。