National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)
GM058600
米国
National Institutes of Health/National Cancer Institute (NIH/NCI)
CA228340
米国
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)
GM141908
米国
引用
ジャーナル: EMBO J / 年: 2022 タイトル: Oxidative stress protein Oxr1 promotes V-ATPase holoenzyme disassembly in catalytic activity-independent manner. 著者: Md Murad Khan / Seowon Lee / Sergio Couoh-Cardel / Rebecca A Oot / Hyunmin Kim / Stephan Wilkens / Soung-Hun Roh / 要旨: The vacuolar ATPase (V-ATPase) is a rotary motor proton pump that is regulated by an assembly equilibrium between active holoenzyme and autoinhibited V -ATPase and V proton channel subcomplexes. ...The vacuolar ATPase (V-ATPase) is a rotary motor proton pump that is regulated by an assembly equilibrium between active holoenzyme and autoinhibited V -ATPase and V proton channel subcomplexes. Here, we report cryo-EM structures of yeast V-ATPase assembled in vitro from lipid nanodisc reconstituted V and mutant V . Our analysis identified holoenzymes in three active rotary states, indicating that binding of V to V provides sufficient free energy to overcome V autoinhibition. Moreover, the structures suggest that the unequal spacing of V 's proton-carrying glutamic acid residues serves to alleviate the symmetry mismatch between V and V motors, a notion that is supported by mutagenesis experiments. We also uncover a structure of free V bound to Oxr1, a conserved but poorly characterized factor involved in the oxidative stress response. Biochemical experiments show that Oxr1 inhibits V -ATPase and causes disassembly of the holoenzyme, suggesting that Oxr1 plays a direct role in V-ATPase regulation.