SYNAPTIC FUNCTION IN THE NEMATODE C ELEGANS

C 线虫的突触功能

• 批准号: 2273498
• 负责人: ERIK M JORGENSEN
• 金额: $ 21.67万
• 依托单位: UNIVERSITY OF UTAH
• 依托单位国家: 美国
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-09-01 至 1999-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2273498
• 关键词: Caenorhabditis elegans; cell free system; confocal scanning microscopy; endocytosis; exocytosis; gene mutation; genetic polymorphism; immunoelectron microscopy; laboratory rabbit; molecular cloning; nerve /myelin protein; neural transmission; nucleic acid sequence; open reading frames; protein structure function; synaptic vesicles

How do synaptic vesicles fuse with the plasma membrane? How are the components of the synaptic vesicle recycled? To answer these questions we propose to use genetic and cell biological techniques to identify and characterize proteins required for synaptic function in the nematode Caenorhabditis elegans. So far we have identified eleven genes that are required for neurotransmission in C. elegans. First, ric-5 and ric-7, two of these eleven genes, will be characterized at a molecular level. Null alleles will be isolated, these genes cloned, and the subcellular location of their gene products characterized. Finally, the synaptic morphology and the distribution of synaptic vesicle components in ric-5 and ric-7 mutants will be characterized. Second,new loci that function at the synapse will be identified. It is likely that mutations that eliminate all synaptic function will be lethal. We have devised a screen that can isolate both viable and lethal mutations that affect neurotransmission. This screen is even more powerful since it selects for such mutations by pharmacologically eliminating wild-type animals. Viable and lethal mutations from this screen that specifically disrupt nervous function will be genetically characterized. In summary, these genetic studies will complement existing biochemical studies of the synapse in two ways: (l) The proposed screens will identify new proteins that function in the synapse. These results will aid researchers using biochemical approaches because vertebrate homologs of these proteins can be identified. The activity of these proteins can then be tested in cell free assays that reconstitute vesicular exocytosis in vitro. (2) The analysis of the synaptic defects in mutants provides functional data about the role of particular proteins in neurotransmission in vivo. Together, these results will significantly advance our understanding of the molecular events involved in the exocytosis and endocytosis of synaptic vesicles. These basic studies may provide reagents that eventually can be used to alleviate the symptoms of myasthenia gravis, amyotrophic lateral sclerosis, and Alzheimer's Disease. In addition, we have found that at least three of the genes isolated in our screens seem to affect endocytosis at the nerve terminal. Endocytosis is the most common mechanism of viral entry into cells. The mechanisms of endocytosis elucidated in this proposal may provide a clearer understanding of the mechanisms of viral infection, particularly those that attack neurons or cause motor disease such as Herpes or HIV.

突触囊泡如何与质膜融合？怎么样 突触囊泡回收的组件？要回答这些问题 建议使用遗传和细胞生物学技术识别和 表征线虫突触功能所需的蛋白质 秀丽隐杆线虫。 到目前为止，我们已经确定了11个基因 秀丽隐杆线虫中的神经传递。首先，RIC-5和RIC-7，其中两个 11个基因将在分子水平上进行表征。无等位基因 将分离出来，克隆这些基因，并将其亚细胞位置 他们的基因产品的特征。最后，突触形态和 RIC-5和RIC-7突变体中突触囊泡成分的分布 将被描述。 其次，将确定该功能的新基因座。这是 消除所有突触功能的突变可能是致命的。 我们设计了一个可以隔离可行和致命突变的屏幕 这会影响神经传递。这个屏幕更加强大，因为它 通过药理学消除野生型来选择此类突变 动物。该屏幕的可行和致命的突变特别是 破坏神经功能将以遗传表征。 总而言之，这些遗传研究将补充现有的生化 通过两种方式对突触的研究：（l）提议的屏幕将识别 在突触中起作用的新蛋白质。这些结果将有助于 研究人员使用生化方法，因为 这些蛋白质可以识别。这些蛋白质的活性可以 在无细胞测定中进行测试，以重建囊泡胞吐作用 体外。 （2）突变体突触缺陷的分析提供了 有关特定蛋白质在神经传递中的作用的功能数据 体内。这些结果在一起将大大推动我们的 理解胞吐作用涉及的分子事件和 突触囊泡的内吞作用。这些基础研究可能会提供试剂 最终可以用来减轻肌无力的症状 GRAVIS，肌萎缩性侧面硬化症和阿尔茨海默氏病。在 此外，我们发现至少三个基因在我们的 筛选似乎会影响神经末端的内吞作用。内吞作用是 病毒进入细胞的最常见机制。机制 在本提案中阐明的内吞作用可能会更清晰 了解病毒感染的机制，尤其是那些 该攻击神经元或引起运动疾病，例如疱疹或艾滋病毒。