Regulated Splicing of the Cholinergic Gene Locus

描述(申请人提供)：这项建议的目的是对土壤线虫线虫中乙酰胆碱的合成和包装进行分子和遗传分析。这些研究集中在两个基因和蛋白质上：CHA-1是胆碱乙酰转移酶(ChAT)的结构基因，合成神经递质乙酰胆碱；UNC-17是编码突触小囊乙酰胆碱转运体(VAChT)的基因；CHA-1和UNC-17紧密连锁，定义了胆碱能基因位点。到目前为止所研究的所有后生动物都存在类似的基因组结构，这表明功能限制作用于维持这种类型的基因组组织。线虫用于这些研究是因为它简单的神经系统，它易于进行遗传和分子分析，以及方便的DNA介导性转化技术。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机制和调控的因素。这些研究的结果将阐明神经末梢内用于协调神经递质供需的机制。 公共卫生相关性：虽然拟议的研究是基础研究，但它们显然与健康相关，因为已在许多神经、神经肌肉和精神疾病中发现乙酰胆碱代谢和/或胆碱能功能的改变，包括先天性肌无力综合征、阿尔茨海默病和抑郁症。

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.