The vacuolar H+‐adenosine triphosphatases (vATPases) acidify multiple intracellular organelles, including synaptic vesicles (SVs) and secretory granules. Acidification of SVs represents a critical point during the SV cycle: without acidification, neurotransmitters cannot be loaded into SVs. Despite the obvious importance of the vesicle acidification process for neurotrasmission and the life of complex organisms, little is known about the regulation of vATPase at the neuronal synapse. In addition, the composition of the vATPase complex on the SVs is unclear. Here, we summarize the key features of vATPase found on SVs, and propose a model of how vATPase activity is regulated during the SV cycle. It is anticipated that the information from the SV lumen is communicated to SV surface in order to signal successful acidification and neurotransmitter loading: we postulate here that the regulators of the vATPase activity exist (e.g., Rabconnectin‐3) that promote the recruitment of SV peripheral proteins and, consequently, SV fusion.

中文翻译：

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神经元突触中突触小泡酸化的调节

液泡 H+-腺苷三磷酸酶 (vATPases) 酸化多种细胞内细胞器，包括突触小泡 (SVs) 和分泌颗粒。SVs 的酸化代表了 SV 循环中的一个临界点：没有酸化，神经递质就无法加载到 SVs 中。尽管囊泡酸化过程对神经传递和复杂生物体的生命具有明显的重要性，但对神经元突触中 vATPase 的调节知之甚少。此外，SV 上 vATPase 复合物的组成尚不清楚。在这里，我们总结了在 SV 上发现的 vATPase 的主要特征，并提出了一个关于在 SV 周期中如何调节 vATPase 活性的模型。