Juhaszova 2019 bioRxiv
Juhaszova M, Kobrinsky E, Zorov DB, Nuss HB, Yaniv Y, Fishbein KW, de Cabo R, Montoliu L, Gabelli SB, Aon MA, Cortassa S, Sollott SJ (2019) ATP synthase K+- and H+-flux drive ATP synthesis and enable mitochondrial K+-uniporter function. bioRxiv doi: https://doi.org/10.1101/355776 . |
Juhaszova M, Kobrinsky E, Zorov DB, Nuss HB, Yaniv Y, Fishbein KW, de Cabo R, Montoliu L, Gabelli SB, Aon MA, Cortassa S, Sollott SJ (2019) bioRxiv
Abstract: ATP synthase (F1Fo) synthesizes daily our bodyโs weight in ATP, whose production-rate can be transiently increased several-fold. Using purified mammalian F1Fo-reconstituted proteoliposomes and isolated mitochondria, we show that F1Fo utilizes both H+- and K+-transport (because of >106-fold K+ excess vs H+) to drive ATP synthesis with the H+:K+ permeability of ~106:1. F1Fo can be upregulated by endogenous survival-related proteins (Bcl-xL, Mcl-1) and synthetic molecules (diazoxide, pinacidil) to increase its chemo-mechanical efficiency via IF1. Increasing K+- and H+-driven ATP synthesis enables F1Fo to operate as a primary mitochondrial K+-uniporter regulating energy supply-demand matching, and as the recruitable mitochondrial KATP-channel that can limit ischemia-reperfusion injury. Isolated mitochondria in the presence of K+ can sustain ~3.5-fold higher ATP-synthesis-flux (vs K+ absence) driven by a 2.7:1 K+:H+ stoichiometry with unaltered OxPhos coupling. Excellent agreement between F1Fo single-molecule and intact-mitochondria experiments is consistent with K+-transport through ATP synthase driving a major fraction of ATP synthesis.
โข Bioblast editor: Plangger M