Snapshots of a rotary pump Vesicular- or vacuolar-type adenosine triphosphatases (V-ATPases) are ATP-hydrolysis–driven proton pumps. In neurons, V-ATPase activity generates a proton gradient across the membrane of synaptic vesicles so that neurotransmitters can be loaded into the vesicles. Abbas et al. developed a method to purify V-ATPase from rat brain and determined the structure of the entire complex by cryo–electron microscopy. Native mass spectrometry showed that the preparation was homogeneous and complemented structural studies by confirming the subunit composition. Three rotational states were resolved at better than 4-angstrom resolution, providing insight into the conformational changes that couple ATP hydrolysis to proton pumping. Science, this issue p. 1240 Cryo–electron microscopy and mass spectrometry reveal the subunit composition and lend insight into how the V-ATPase assembles and functions. In neurons, the loading of neurotransmitters into synaptic vesicles uses energy from proton-pumping vesicular- or vacuolar-type adenosine triphosphatases (V-ATPases). These membrane protein complexes possess numerous subunit isoforms, which complicates their analysis. We isolated homogeneous rat brain V-ATPase through its interaction with SidK, a Legionella pneumophila effector protein. Cryo–electron microscopy allowed the construction of an atomic model, defining the enzyme’s ATP:proton ratio as 3:10 and revealing a homolog of yeast subunit f in the membrane region, which we tentatively identify as RNAseK. The c ring encloses the transmembrane anchors for cleaved ATP6AP1/Ac45 and ATP6AP2/PRR, the latter of which is the (pro)renin receptor that, in other contexts, is involved in both Wnt signaling and the renin-angiotensin system that regulates blood pressure. This structure shows how ATP6AP1/Ac45 and ATP6AP2/PRR enable assembly of the enzyme’s catalytic and membrane regions.

中文翻译：

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哺乳动物大脑中 V-ATP 酶的结构

旋转泵的快照 水泡型或液泡型三磷酸腺苷酶 (V-ATP 酶) 是 ATP 水解驱动的质子泵。在神经元中，V-ATPase 活性在突触小泡的膜上产生质子梯度，以便神经递质可以加载到小泡中。阿巴斯等人。开发了一种从大鼠脑中纯化 V-ATPase 的方法，并通过低温电子显微镜确定了整个复合物的结构。本机质谱表明，该制剂是均质的，并通过确认亚基组成补充了结构研究。三种旋转状态以优于 4 埃的分辨率得到解析，从而深入了解将 ATP 水解与质子泵送相结合的构象变化。科学，本期第 3 页。1240 冷冻电子显微镜和质谱分析揭示了亚基的组成，并有助于深入了解 V-ATPase 如何组装和发挥作用。在神经元中，将神经递质加载到突触小泡中使用来自质子泵泡型或液泡型三磷酸腺苷酶 (V-ATPases) 的能量。这些膜蛋白复合物具有许多亚基异构体，这使它们的分析复杂化。我们通过与嗜肺军团菌效应蛋白 SidK 的相互作用分离了均质的大鼠脑 V-ATP 酶。冷冻电子显微镜允许构建原子模型，将酶的 ATP：质子比定义为 3:10，并揭示膜区域中酵母亚基 f 的同源物，我们暂时将其鉴定为 RNAseK。c 环包围切割的 ATP6AP1/Ac45 和 ATP6AP2/PRR 的跨膜锚，后者是（原）肾素受体，在其他情况下，它参与 Wnt 信号传导和调节血压的肾素-血管紧张素系统。这种结构显示了 ATP6AP1/Ac45 和 ATP6AP2/PRR 如何使酶的催化区域和膜区域能够组装。