加拿大病童医院John L. Rubinstein研究组实现原生突触小泡中V-ATP酶的高分辨率电子冷冻显微镜观察。相关论文于2024年6月20日发表在《科学》杂志上。

研究人员表示，神经系统中的细胞间通信是通过向神经元之间的突触间隙释放神经递质来实现的。在突触前神经元中，质子泵囊泡型或空泡型ATP酶（V-ATP酶）为神经递质装入突触小泡（SV）提供动力，V₁复合物在外渗之前与酶的膜区解离。

研究人员利用与V-ATP酶结合的细菌效应蛋白SidK从大鼠大脑中分离出SV。通过单颗粒电子冷冻显微镜，研究人员确定了原生SV膜内V-ATP酶的高分辨率结构。在该结构中，有规则间隔的胆固醇分子装饰着酶的转子，丰富的SV蛋白突触素按比例结合了该复合物。囊泡装载过程中的ATP水解导致V₁从SV膜上脱落，这表明装载足以诱导该酶解离。

附：英文原文

Title: High-resolution electron cryomicroscopy of V-ATPase in native synaptic vesicles

Author: Claire E. Coupland, Ryan Karimi, Stephanie A. Bueler, Yingke Liang, Gautier M. Courbon, Justin M. Di Trani, Cassandra J. Wong, Rayan Saghian, Ji-Young Youn, Lu-Yang Wang, John L. Rubinstein

Issue&Volume: 2024-06-20

Abstract: Intercellular communication in the nervous system occurs through the release of neurotransmitters into the synaptic cleft between neurons. In the presynaptic neuron, the proton pumping vesicular- or vacuolar-type ATPase (V-ATPase) powers neurotransmitter loading into synaptic vesicles (SVs), with the V1 complex dissociating from the membrane region of the enzyme before exocytosis. We isolated SVs from rat brain using SidK, a V-ATPase-binding bacterial effector protein. Single particle electron cryomicroscopy allowed high-resolution structure determination of V-ATPase within the native SV membrane. In the structure, regularly spaced cholesterol molecules decorate the enzyme’s rotor and the abundant SV protein synaptophysin binds the complex stoichiometrically. ATP hydrolysis during vesicle loading results in loss of V1 from the SV membrane, suggesting that loading is sufficient to induce dissociation of the enzyme.

DOI: adp5577

Source: https://www.science.org/doi/10.1126/science.adp5577