胆固醇调控syntaxin-1A寡聚化的分子模拟研究与实验验证

SNARE proteins are key components for neuronal exocytosis in neurons and neuroendocrine cells, via mediating the fusion between synaptic vesicle and plasma membranes for neurotransmitter and endocrine release. Syntaxin-1A is main member of SNARE protein family and anchored to plasma membrane by single-pass transmembrane domain. Its oligomerization at pre-fusion stage plays an important role in fusion initiation and fusion pore formation, which is also modulated by cholesterol in plasma membrane. The project aims to investigate the structural basis for the formation of syntaxin-1A oligomers and the regulatory mechanism imposed by cholesterol, and predict the functionality of syntaxin-1A oligomers via interacting with biological membrane. The in vitro oligomerization and fusion assay, as well as intracellular exocytosis measurement designed based on theoretical prediction would further probe the leading factors contributing to the cholesterol-regulated oligomerization of syntaxin-1A and membrane fusion. Our research will provide insights and theoretical basis into understanding the action of mechanism that interaction between SNARE proteins and membrane regulated by cholesterol.

SNARE蛋白是神经元和内分泌细胞发生胞吐事件的关键因子，通过介导突触囊泡膜与质膜的融合完成神经递质和内分泌激素的释放。Syntaxin-1A是SNARE家族的关键成员，通过单跨膜螺旋锚定于质膜上，其在融合前的寡聚化作用在膜融合的启动以及融合孔的形成中具有关键作用，且受到膜组分胆固醇的调控。本项目拟通过分子模拟手段研究syntaxin-1A寡聚化形成的结构基础以及胆固醇对其寡聚化的调控机制，预测其与生物膜相互作用在膜融合中的功能。基于理论预测的体外寡聚化、膜融合检测以及细胞胞吐实验进一步验证胆固醇调控syntaxin-1A寡聚化以及膜融合的主导因素。本研究将为理解胆固醇调控下的SNARE蛋白间以及与生物膜间相互作用在介导高效膜融合事件中的作用机理提供理论基础和依据。