Calcium sensing by the C2B domain of synaptotagmin

突触结合蛋白 C2B 结构域的钙感应

• 批准号: 7046798
• 负责人: Camin Dean
• 金额: $ 5.04万
• 依托单位: UNIVERSITY OF WISCONSIN-MADISON
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-04-01 至 2008-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7046798
• 关键词: PC12 cells; binding sites; biosensor device; brain electrical activity; calcium flux; electrical conductance; exocytosis; gene expression; genetically modified animals; intermolecular interaction; laboratory mouse; laboratory rat; mutant; neural transmission; neurotransmitter transport; postdoctoral investigator; protein binding; protein structure function; synaptotagmin; tissue /cell culture; transcription factor

DESCRIPTION (provided by applicant): Precise signaling between neurons is required for normal brain function, and aberrant synaptic transmission results in nervous system disorders. Synaptic transmission requires calcium influx and the transduction of this calcium signal into release of neurotransmitter. The C2B domain of synaptotagmin is thought to act as the calcium sensor during exocytosis. Different C2B calcium binding mutants exhibit differences in effector interactions allowing a dissection of the role of these sites and interactions in distinct steps of fusion pore kinetics. The goal of this proposal is to test the hypothesis that C2B calcium binding mutants deficient in specific effector interactions show deficiencies in distinct kinetic steps of exocytosis during the opening and dilation of effusion pores and in synaptic transmission. These hypotheses will be tested by 1) assaying the ability of synaptotagmin C2B calcium binding mutants to bind presynaptic proteins in vitro, 2) performing amperometry on PC12 cells expressing these mutants to assess whether mutants deficient in effector interactions are deficient in the formation or dilation of fusion pores, and 3) determining whether these mutants are deficient in synaptic transmission in neurons.

描述（由申请人提供）：正常脑功能需要神经元之间的精确信号传导，而异常的突触传播导致神经系统疾病。 突触传播需要钙的流入，并将该钙信号转导向神经递质的释放。突触毒素的C2B结构域被认为是胞吐作用期间的钙传感器。不同的C2B钙结合突变体在效应相互作用方面表现出差异，允许在融合孔动力学的不同步骤中解剖这些位点和相互作用的作用。该提案的目的是检验以下假设：在特定效应子相互作用中缺乏缺陷的C2B钙结合突变体在开放和扩张孔隙和突触传播中显示出不同的动力学步骤中的缺陷。 这些假设将通过1）测试突触agmin C2b钙结合突变体在体外结合前突触前蛋白的能力，2）对表达这些突变体的PC12细胞进行安培法以评估效应相互作用中缺陷在效应相互作用中是否有效地构成或在融合孔中的扩展是否有效。