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Juhaszova 2021 Function (Oxf)

From Bioblast
Publications in the MiPMap
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 (2021) ATP synthase K<sup>+</sup>- and H<sup>+</sup>-fluxes drive ATP synthesis and enable mitochondrial K<sup>+</sup>-"uniporter" function: I. Characterization of ion fluxes. Function (Oxf) 3(2):zqab065. doi: 10.1093/function/zqab065

ยป PMID: 35229078 Open Access

Juhaszova M, Kobrinsky E, Zorov DB, Nuss HB, Yaniv Y, Fishbein KW, de Cabo R, Montoliu L, Gabelli SB, Aon Miguel A, Cortassa Sonia, Sollott SJ (2021) Function (Oxf)

Abstract: ATP synthase (F1Fo) synthesizes daily our body's weight in ATP, whose production-rate can be transiently increased several-fold to meet changes in energy utilization. Using purified mammalian F1Fo-reconstituted proteoliposomes and isolated mitochondria, we show F1Fo can utilize both ฮ”ฮจmt-driven H+- and K+-transport to synthesize ATP under physiological pH = 7.2 and K+ = 140 mEq/L conditions. Purely K+-driven ATP synthesis from single F1Fo molecules measured by bioluminescence photon detection could be directly demonstrated along with simultaneous measurements of unitary K+ currents by voltage clamp, both blocked by specific Fo inhibitors. In the presence of K+, compared to osmotically-matched conditions in which this cation is absent, isolated mitochondria display 3.5-fold higher rates of ATP synthesis, at the expense of 2.6-fold higher rates of oxygen consumption, these fluxes being driven by a 2.7:1 K+: H+ stoichiometry. The excellent agreement between the functional data obtained from purified F1Fo single molecule experiments and ATP synthase studied in the intact mitochondrion under unaltered OxPhos coupling by K+ presence, is entirely consistent with K+ transport through the ATP synthase driving the observed increase in ATP synthesis. Thus, both K+ (harnessing ฮ”ฮจmt) and H+ (harnessing its chemical potential energy, ฮ”ฮผH) drive ATP generation during normal physiology.

โ€ข Bioblast editor: Gnaiger E โ€ข O2k-Network Lab: US MD Baltimore Ferrucci L

Labels: MiParea: Respiration 

Preparation: Isolated mitochondria  Enzyme: Complex V;ATP synthase  Regulation: ATP production, Coupling efficiency;uncoupling, Ion;substrate transport, mt-Membrane potential  Coupling state: LEAK, OXPHOS 

HRR: Oxygraph-2k