NEUROFIBROMATOSIS TYPE 1 GENE PRODUCT

神经纤维瘤病I型(NF1)是一种遗传性周围神经疾病 全球每3500人中就有一人受到影响的系统，我们最近 证明NF1基因产物是GAP(GTP)酶的成员 激活蛋白)蛋白家族下调ras蛋白， 鸟嘌呤核苷酸结合蛋白参与细胞生长调控 还有肿瘤。在此应用程序中，我们建议执行详细的 NF1蛋白的特性主要集中在以下几个方面 实验。[I]NF1 GAP活性和相互作用的表征 在nf1和ras蛋白之间(1)nf1的催化结构域将是 表达NF1的大肠杆菌或昆虫细胞的纯化及其GAP活性 也将接受调查。(2)NF1与ras蛋白的相互作用 将通过生化实验进行研究。(3)催化剂中的区域 负责GAP活动以及与 RAS蛋白将通过NF1蛋白的体外诱变来确定。 赋予靶ras蛋白特异性的区域(S)也将是 下定决心。(4)脂类似乎也是相互作用中的一个参与者。 NF1-GAP活性的脂质敏感性将通过使用各种 脂类和脂肪酸。[二]催化侧翼区域的功能 通过比较催化剂的GAP活性来研究结构域 结构域多肽和同时包含催化和 侧翼区域。[III]NF1蛋白在体内的特性将由 准备一组抗体。翻译后修饰， 亚细胞定位和任何相关蛋白的存在将 被调查。[IV]突变的NF1蛋白的特征是 已知突变蛋白的纯化以及通过筛选不同类型的 组织样本，包括神经纤维瘤病患者的组织样本。

Neurofibromatosis type I (NF1) is a genetic disease of peripheral nervous system that afflicts 1 in 3500 people worldwide, We have recently demonstrated that the NF1 gene product is a member of GAP (GTPase activating protein) protein family which down-regulate ras proteins, guanine nucleotide binding protein involved in regulation of cell growth as well as neoplasia. In this application, we propose to carry out a detailed characterization of the NF1 protein by concentrating on the following experiments. [I] Characterization of NF1 GAP activity and interaction between NF1 and ras proteins (1) The catalytic domain of NF1 will be purified from E. coli or insect cells expressing NF1 and their GAP activity as well will be investigated. (2) Interaction between NF1 and ras proteins will be studied by biochemical experiments. (3) Regions in the catalytic domain responsible for the GAP activity as well as for the interaction with ras proteins will be determined by in vitro mutagenesis of the NF1 protein. A region(s) conferring specificity of target ras proteins will be also be determined. (4) Lipids also appears to be a player in the interaction. Lipid sensitivity of NF1-GAP activity will be addressed by using various lipids and fatty acids. [II] Function of regions flanking the catalytic domain will be investigated by comparing GAP activity of the catalytic domain polypeptide and a polypeptide containing both the catalytic and the flanking regions. [III] NF1 protein in vivo will be characterized by preparing a battery of antibodies. Posttranslational modification, subcellular localization and the presence of any associated proteins will be investigated. [IV] Mutant NF1 protein will be characterized by the purification of known mutant proteins as well as by screening various tissue samples including ones derived from neurofibromatosis patients.