NERVE GROWTH FACTOR RECEPTOR--A MOLECULAR ANALYSIS

神经生长因子（NGF）是一种重要的生长调节因子， 多肽，其促进细胞的存活和分化， 发育中的神经系统中未成熟的神经母细胞。 不像 大多数刺激细胞复制的生长激素， 抑制细胞增殖并诱导细胞成熟 带有特定的神经生长因子受体 因此，NGF-NGF受体 交互作用是一个重要的模型系统， 研究调节细胞生长的正常机制 和差异化。 此外，由于NGF的作用 甚至延伸到带有功能性受体NGF的肿瘤细胞 作为生长抑制剂具有潜在的临床意义 神经嵴起源的肿瘤。 虽然NGF是第一个被鉴定的生长因子， 作用机制还不清楚，除了它 通过与高亲和力细胞表面结合来启动作用 受体的 这项建议旨在界定以下方面的作用： NGF受体在启动细胞对NGF的反应中，使用 最近克隆的编码人类神经生长因子受体的基因。 将分子生物学和生物化学方法相结合， 用于确定功能活性高的结构 亲和受体 具体而言，我们计划：（a） 人神经生长因子受体克隆入来源于神经细胞的细胞 以确定细胞特征， 负责对NGF的反应性;（B）定义分子 根据受体的高和低亲和力形式， 使用PEG介导的融合的膜融合实验;（c） 确定负责高亲和力的受体的结构域 配体结合、内化和与细胞的相互作用 膜蛋白;（d）生物化学表征高 使用亲和色谱法的亲和受体复合物和（e） 使用基因转移来识别细胞中的其他基因产物 功能活性高亲和性所需的膜 受体的

Nerve growth factor (NGF) is an important growth regulatory polypeptide which promotes the survival and differentiation of immature neuroblasts in the developing nervous system. Unlike most growth hormones which stimulate cell replication, NGF inhibits cell proliferation and induces the maturation of cells bearing specific NGF receptors. Thus, the NGF-NGF receptor interaction serves as an important model system to use in investigating the normal mechanisms which regulate cell growth and differentiation. Furthermore, since the effects of NGF extend even to neoplastic cells bearing functional receptors, NGF is of potential clinical significance as a growth inhibitor of neoplasias of neural crest origin. Although NGF was the first growth factor to be identified, its mechanism of action is not well understood, except that its actions are initiated by binding to a high affinity cell surface receptor. This proposal is directed towards defining the role of the NGF receptor in initiating cellular responses to NGF, using the recently cloned gene that encodes the human NGF receptor. A combined molecular biological and biochemical approach will be used to determine the structure of the functionally active high affinity receptor. Specifically we plan to: (a) transfect the human NGF receptor clone into cells derived from the neural crest to determine the cellular characteristics which are responsible for responsiveness to NGF; (b) define the molecular basis of the high and low affinity forms of the receptor by membrane fusion experiments using PEG-mediated fusion; (c) define the domains of the receptor responsible for high affinity ligand binding, internalization and interactions with cell membrane proteins; (d) biochemically characterize the high affinity receptor complex using affinity chromatography and (e) use gene transfer to identify other gene products in the cell membrane which are required for functionally active high affinity receptor.