Nardone Christopher, Mintseris Julian, He Dingwei, Rutter Justine C, Ebert Benjamin L, Gygi Steven P, Rapoport Tom
Department of Cell Biology, Harvard Medical School, Boston, MA, USA.
Howard Hughes Medical Institute, Boston, MA, USA.
Nat Struct Mol Biol. 2025 Jul 11. doi: 10.1038/s41594-025-01610-9.
Organelles such as lysosomes and synaptic vesicles are acidified by V-ATPases, which consist of a cytosolically oriented V complex that hydrolyzes ATP and a membrane-embedded V complex that pumps protons. In yeast, V-V association is facilitated by the RAVE (regulator of H-ATPase of the vacuolar and endosomal membrane) complex, but how higher eukaryotes assemble V-ATPases remains unclear. Here we identify a metazoan RAVE complex (mRAVE) whose structure and composition are notably divergent from the ancestral counterpart. mRAVE consists of DMXL1 or DMXL2, WDR7 and the central linker ROGDI. DMXL1 and DMXL2 interact with subunits A and D of the inactive, isolated V. On dissipation of proton gradients, mRAVE binds to V and V, forming a supercomplex on the membrane. mRAVE then catalyzes V-V assembly, enabling lysosomal acidification, neurotransmitter loading into vesicles and ATG16L1 recruitment for LC3/ATG8 conjugation onto single membranes. Our findings provide a molecular basis for neurological disorders caused by mRAVE mutations.
溶酶体和突触小泡等细胞器由V-ATP酶酸化，V-ATP酶由一个在胞质中水解ATP的V复合物和一个将质子泵入膜内的V复合物组成。在酵母中，V-V结合由RAVE（液泡和内体膜H-ATP酶调节剂）复合物促进，但高等真核生物如何组装V-ATP酶仍不清楚。在这里，我们鉴定出一种后生动物RAVE复合物（mRAVE），其结构和组成与原始对应物明显不同。mRAVE由DMXL1或DMXL2、WDR7和中央连接体ROGDI组成。DMXL1和DMXL2与无活性的分离V的亚基A和D相互作用。质子梯度消散时，mRAVE与V和V结合，在膜上形成一个超复合物。然后，mRAVE催化V-V组装，实现溶酶体酸化、神经递质装载到囊泡以及ATG16L1募集以将LC3/ATG8缀合到单膜上。我们的发现为mRAVE突变引起的神经疾病提供了分子基础。
