MOLECULAR GENETICS OF TUBEROUS SCLEROSIS 2

结节性硬化症(TSC)是一种多系统疾病 由于许多人中被称为错构瘤的生长的广泛发展 组织和器官，特别是大脑、眼睛、皮肤、肾脏， 心脏、肺和骨骼。TSC遗传为常染色体显性遗传 但有相当一部分患者是零星出现的。 遗传连锁研究表明，这种疾病的基因座存在异质性， 在9号和16号染色体上至少有两个TSC决定基因 分别命名为TSC1和TSC2。16号染色体上的TSC2基因 最近通过位置克隆策略和基因内克隆策略分离 在一些TSC病例中已经记录了该基因的突变。这个 TSC2基因产物名为tuberin，编码1784个氨基酸的蛋白质， 显示了与GTP酶激活蛋白RAP的一小部分同源性 1 GAP。这项建议的目的是扩展我们之前的连锁分析 对TSC进行分子遗传学和生化研究以更好地了解 疾病表型。TSC2基因的详细突变分析 将在TSC2家族中执行，以精确定义 受影响个体的突变。这一分析将扩展到TSC1 TSC1家族的基因一旦在项目3中被分离出来。突变 将在散发性病例中定义TSC1和TSC2基因的谱。 将使用一种系统的方法来扫描突变。这个 我们获得的信息将对提供基于DNA的 在TSC家族中的诊断学，在理解TSC的遗传异质性 这种混乱，最终将产生丰富的信息 Tuberin与TSC1结构功能关系的研究 蛋白。我们还建议产生针对结节蛋白的特异性抗体 结节蛋白的不同结构域以融合蛋白的形式表达 确定其在正常人和TSC2个体中的表达模式。一种知识 关于该蛋白在组织培养细胞中的亚细胞定位 来源于正常和TSC2病例，以及它对 不同的细胞刺激将揭示TSC2中的靶细胞。这个 将测试tuberin推测的Rap1 GAP活性 细菌和杆状病毒的构建。这里提出的研究应该 为更好地了解块茎的损失提供了基础 导致了这种多系统疾病。从长远来看，这将导致 分离与结节蛋白相互作用和解开的蛋白质 一旦确定了结节蛋白和TSC1蛋白之间的联系。

Tuberous sclerosis complex (TSC) is a 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. TSC is inherited as an autosomal dominant disorder, but a significant portion of patients appear sporadically. 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 TSC2 gene on chromosome 16 has been recently isolated by positional cloning strategies and intragenic mutations within this gene have been documented in some TSC cases. The TSC2 gene product named tuberin encodes a 1784 amino acid protein that shows a small stretch of homology to the GTPase activating protein rap 1GAP. This proposal is aimed at extending our previous linkage analysis of TSC to molecular genetic and biochemical studies to better understand the disease phenotype. A detailed mutational analysis of the TSC2 gene will be performed in TSC2 families to precisely define the nature of mutations in affected individuals. This analysis will be extended to TSC1 gene in TSC1 families once this is isolated in Project 3. The mutation spectrum of both TSC1 and TSC2 genes will be defined in sporadic cases. A systematic approach will be used for scanning the mutations. The information that we gain will be very useful for providing a DNA based diagnostics in TSC families, in understanding the genetic heterogeneity in this disorder and finally will yield a wealth of information for correlating the structure function relationship of tuberin and the TSC1 protein. We also propose to generate tuberin specific antibodies to different domains of tuberin expressed as fusion proteins in order to define its expression pattern in normal and TSC2 individuals. A knowledge about the subcellular localization of this protein in tissue culture cells derived from normal and TSC2 cases, and its behavior in response to various cellular stimuli would reveal the target cells in TSC2. The putative rap1 GAP activity of tuberin will be tested employing the bacterial and baculoviral constructs. The studies proposed here should provide the basis for a better understanding of how loss of tuberin results in this multisystem disease. In the long term, this will lead to isolating the proteins with which tuberin interacts as well as unraveling the connection between tuberin and TSC1 protein once this is identified.