Oxidative stress protein Oxr1 promotes V-ATPase holoenzyme disassembly in catalytic activity-independent manner.

Autor: Khan MM; Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, NY, USA., Lee S; School of Biological Science, Institute of Molecular Biology and Genetics, Seoul National University, Seoul, South Korea., Couoh-Cardel S; Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, NY, USA., Oot RA; Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, NY, USA., Kim H; School of Biological Science, Institute of Molecular Biology and Genetics, Seoul National University, Seoul, South Korea., Wilkens S; Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, NY, USA., Roh SH; School of Biological Science, Institute of Molecular Biology and Genetics, Seoul National University, Seoul, South Korea.
Jazyk: angličtina
Zdroj: The EMBO journal [EMBO J] 2022 Feb 01; Vol. 41 (3), pp. e109360. Date of Electronic Publication: 2021 Dec 17.
DOI: 10.15252/embj.2021109360
Abstrakt: The vacuolar ATPase (V-ATPase) is a rotary motor proton pump that is regulated by an assembly equilibrium between active holoenzyme and autoinhibited V 1 -ATPase and V o proton channel subcomplexes. Here, we report cryo-EM structures of yeast V-ATPase assembled in vitro from lipid nanodisc reconstituted V o and mutant V 1 . Our analysis identified holoenzymes in three active rotary states, indicating that binding of V 1 to V o provides sufficient free energy to overcome V o autoinhibition. Moreover, the structures suggest that the unequal spacing of V o 's proton-carrying glutamic acid residues serves to alleviate the symmetry mismatch between V 1 and V o motors, a notion that is supported by mutagenesis experiments. We also uncover a structure of free V 1 bound to Oxr1, a conserved but poorly characterized factor involved in the oxidative stress response. Biochemical experiments show that Oxr1 inhibits V 1 -ATPase and causes disassembly of the holoenzyme, suggesting that Oxr1 plays a direct role in V-ATPase regulation.
(© 2021 The Authors Published under the terms of the CC BY NC ND 4.0 license.)
Databáze: MEDLINE
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