交纳普托胺I和IV促进发射器释放,独立于在C2A域中的Ca2+) 结合
Iain M Robinson1, Ravi Ranjan, Thomas L Schwarz
1Department of Genetics, University of Cambridge, Cambridge CB2 3EH, UK. i.robinson@gen.cam.ac.uk
Nature
|July 12, 2002
概括
交纳普托塔明I的C2A域对于依赖的神经递质释放并不重要. 相关蛋白质Synaptotagmin IV实际上促进了突触传输,挑战了其拟议的抑制作用.
科学领域:
- 神经科学是一个神经科学.
- 分子生物学分子生物学
- 细胞生物学 细胞生物学
背景情况:
- 离子 (Ca2+) 通过促进囊泡融合,在神经末端触发神经递质释放.
- 合成胺I是检测Ca2+的主要候选者,其C2A域参与结合Ca2+并与脂和合成素相互作用.
- 之前对Synaptotagmin I的遗传研究已经产生了关于其作为Ca2+感应触发核聚变的作用的不确定的结果.
研究的目的:
- 为了研究对Ca2+依赖性突触传递所必需的突触胺I C2A域的Ca2+结合部位.
- 确定协同胺IV在突触传播中的功能,特别是它是否起到抑制剂或促进剂的作用.
主要方法:
- 在Synaptotagmin I C2A域的Ca2+结合部位中突变一个关键的阿斯巴酸盐.
- 在Drosophila缺乏内源性Synaptotagmin I.表达突变的Synaptotagmin I. 在Drosophila缺乏内源性Synaptotagmin I.
- 评估Ca2+依赖的突触传递特性在修饰的Drosophila.
主要成果:
- 破坏突触胺I C2A域的Ca2+结合部位并没有改变Ca2+依赖的突触传输.
- 在缺乏该蛋白质的虫中,Synaptotagmin IV有效地替代了Synaptotagmin I.
- 发现四次性纳普托塔格能促进,而不是抑制突触传输.
结论:
- 对于Ca2+依赖的突触传输,突触胺的C2A域不需要.
- 协同胺IV在促进突触传播方面发挥着作用,这与之前认为它是一种抑制剂的假设相反.
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