Regulated Splicing of the Cholinergic Gene Locus

描述（由申请人提供）：本提案的目的是对土壤线虫秀丽隐杆线虫中乙酰胆碱的合成和包装进行分子和遗传学分析。这些研究主要集中在两个基因和蛋白质上：cha-1是合成神经递质乙酰胆碱的胆碱乙酰转移酶（ChAT）的结构基因，unc-17是编码突触囊泡乙酰胆碱转运蛋白（VAChT）的基因；Cha-1和unc-17紧密相连，确定了“胆碱能基因位点”。到目前为止，所有后生动物都存在类似的基因组结构，这表明功能限制维持了这种类型的基因组组织。秀丽隐杆线虫被用于这些研究是因为其简单的神经系统，易于遗传和分子分析，以及方便的dna介导转化技术的可用性。具体目的包括测试胆碱能转录物选择性剪接的模型，并确定参与这种剪接的机制和调节的因素。这些研究结果将阐明神经末梢内协调神经递质供需的机制。

DESCRIPTION (provided by applicant): The purpose of this proposal is to pursue molecular and genetic analysis of acetylcholine synthesis and packaging in the soil nematode Caenorhabditis elegans. These studies focus on two genes and proteins: cha-1 is the structural gene for choline acetyltransferase (ChAT), the enzyme which synthesizes the neurotransmitter acetylcholine, and unc-17 is the gene which encodes the synaptic vesicle acetylcholine transporter (VAChT); cha-1 and unc-17 are tightly linked and define the "cholinergic gene locus". A similar genomic structure is present in all metazoans thus far examined, suggesting that functional constraints operate to maintain this type of genomic organization. C. elegans is being used for these studies because of its simple nervous system, its ease of genetic and molecular analysis, and the availability of convenient DNA-mediated transformation techniques. The specific aims include testing a model of cholinergic transcript alternative splicing, and identifying factors involved in the mechanism and the regulation of such splicing. The results of these studies will elucidate the mechanisms used within nerve terminals to coordinate neurotransmitter supply and demand. PUBLIC HEALTH RELEVANCE: Although the proposed studies are basic research, they are clearly relevant to health, since alterations in acetylcholine metabolism and/or cholinergic function have been identified in many neurological, neuromuscular, and psychiatric disorders, including congenital myasthenic syndromes, Alzheimer's disease, and depression.