单分子生物物理技术在神经递质释放研究中的应用

Single-molecule Biophysical Studies of Neurotransmitter Release

神经递质的释放在神经信号传导中起着至关重要的作用.神经递质释放严格依赖SNARE蛋白的动态组装和钙离子触发的膜融合过程.最新研究发现,神经递质释放还受到神经退行性疾病中关键的标志蛋白分子的影响.当前研究者以体外膜融合重组体系为基础,发展了多种单分子生物物理技术,为进一步阐明神经递质释放的分子机制和神经退行性疾病的发病机理提供了新的视角和手段.

Fast neurotransmitter release plays an important role in neuron communications. The membrane fusion process mediated by SNAREs can be significantly influenced by proteins related to neurodegeneration. In order to understand the molecular mechanism, a series of single molecule biophysical assays have been developed for observing content mixing rather than（or in addition to） lipid mixing at the single-vesicle level. Based on proteoliposomes reconstituted with v- or t-SNARE proteins, people have developed single vesicle-vesicle fusion assays that monitor lipid or content mixing and both lipid and content of individual vesicle-vesicle pairs. By simultaneously observing lipid and content mixing indicators of single vesicle pairs, these assays provide a foundation to investigate the influence of other regulation factors on SNARE-mediated membrane fusion.Furthermore, these single vesicle-vesicle fusion assays have been applied for systematically characterizing proteins related to neurodegeneration（CSPα, α-Syn, and Aβ） during different stages（docking, hemifusion, and full fusion）of SNARE-mediated membrane fusion.