CHARACTERIZATION OF TSC PROTEIN HAMARTIN AND TUBERIN

TSC 蛋白错构瘤蛋白和马铃薯蛋白的表征

• 批准号: 6360325
• 负责人: VIJAYA RAMESH
• 金额: $ 17.3万
• 依托单位: MASSACHUSETTS GENERAL HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-09-30 至 2006-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6360325
• 关键词: Drosophilidae; carcinogenesis; disease /disorder model; gene expression; human subject; laboratory mouse; loss of heterozygosity; neoplastic growth; neoplastic transformation; neuromuscular junction; northern blottings; patient oriented research; polymerase chain reaction; protein protein interaction; protein structure function; tuberous sclerosis; tumor suppressor proteins

DESCRIPTION (provided by applicant): Tuberous sclerosis complex is multisystem disorder characterized by the widespread development of growths known as hamartomas in many tissues and organs, particularly within the brain, eyes, skin, kidneys, heart, lungs and skeleton. The most severely affected system is the central nervous system with the occurrence in affected individuals of seizures (80-90 percent), mental retardation (50-60 percent), and autism (up to 50 percent). TSC is inherited as an autosomal dominant disorder, but approximately two-thirds of affected patients are sporadic due to new germline mutations. Genetic linkage studies have shown locus heterogeneity for the disease, with at least two TSC determining genes on chromosomes 9 and 16 which have been termed TSC1 and TSC2 respectively. The TSC1 gene encodes a novel protein, hamartin that contains a single transmembrane domain and a large cytoplasmic tail with a coiled-coil domain. The TSC2 gene encodes a novel protein tuberin that contains a region of homology to the GTPase activating protein rap1GAP. We have performed a comprehensive mutational analysis of the TSC1 and TSC2 genes and noted that TSC1 mutations are significantly underrepresented in sporadic patients. However, the occurrence of the second somatic mutation in TSC lesions, particularly brain lesions is not clear. In order to understand whether this is due to cellular pleomorphism, or if haploinsufficiency of tuberin/hamartin is enough to promote tumor genesis, we will perform genetic analysis on laser capture microdissected lesions. We have identified a novel protein associated with Myc named Pam as an interacting protein for tuberin. Mutations in both the Drosophila (hiw) and C. elegans (rpm-1) homologs of Pam show synaptic overgrowth. Our hypothesis that Pam is an essential component of the tuberin-hamartin complex, particularly in the CNS where these proteins may have a critical role in cortical neuron function will be examined. The domain of Pam that interacts with tuberin reveals 90 percent similarity with the fly homolog HIW. The possible physical and genetic interaction between the Drosophila TSC2 product Gigas and HIW will be examined. Thus the studies aimed at defining the role of tuberin-hamartin in the mammalian CNS will be further strengthened by the Drosophila model system where genetic manipulations are possible. The information obtained here will elucidate the physiological functions of these tumor suppressors, which will aid in designing better therapies.

描述（由申请人提供）：结节性硬化症是多系统的 以广泛生长的生长为特征的疾病，称为 许多组织和器官中的错构瘤，特别是大脑、眼睛、 皮肤、肾脏、心脏、肺和骨骼。受影响最严重的系统是 中枢神经系统在受影响的个体中发生 癫痫发作（80-90%）、智力低下（50-60%）和自闭症（高达 50%）。 TSC 是一种常染色体显性遗传疾病，但 大约三分之二的受影响患者由于新种系而呈散发性 突变。遗传连锁研究表明基因座异质性 疾病，在 9 号和 16 号染色体上至少有两个 TSC 决定基因， 分别称为 TSC1 和 TSC2。 TSC1基因编码一种新的 错构蛋白，含有一个跨膜结构域和一个大的 具有卷曲螺旋结构域的细胞质尾部。 TSC2基因编码一种新的 蛋白质马铃薯蛋白含有与 GTP 酶激活同源的区域 蛋白质rap1GAP。我们对其进行了全面的突变分析 TSC1 和 TSC2 基因，并指出 TSC1 突变显着 散发患者中代表性不足。然而，第二件事的发生 TSC病变，特别是脑部病变中的体细胞突变尚不清楚。在 为了了解这是否是由于细胞多形性，或者是否 马铃薯蛋白/错构瘤单倍体不足足以促进肿瘤发生，我们 将对激光捕获显微切割病变进行遗传分析。我们有 鉴定出一种与 Myc 相关的新蛋白，名为 Pam，作为一种相互作用的蛋白 马铃薯蛋白。果蝇 (hiw) 和线虫中的突变 Pam 的 (rpm-1) 同系物显示突触过度生长。我们假设 Pam 是 马铃薯蛋白-错构蛋白复合物的重要组成部分，特别是在中枢神经系统中 这些蛋白质可能在皮质神经元功能中发挥关键作用 被检查。 Pam 与马铃薯蛋白相互作用的结构域揭示了 90% 与果蝇同系物 HIW 的相似性。可能的身体和遗传因素 将检查果蝇 TSC2 产物 Gigas 和 HIW 之间的相互作用。 因此，这些研究旨在确定马铃薯蛋白-错构蛋白在 果蝇模型系统将进一步加强哺乳动物的中枢神经系统，其中 基因操纵是可能的。此处获得的信息将 阐明这些肿瘤抑制因子的生理功能，这将有助于 帮助设计更好的疗法。