scholarly journals Reversible Thiol Oxidation Inhibits the Mitochondrial ATP Synthase in Xenopus laevis Oocytes

Antioxidants ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 215 ◽  
Author(s):  
James Cobley ◽  
Anna Noble ◽  
Rachel Bessell ◽  
Matthew Guille ◽  
Holger Husi
Keyword(s):  
Xenopus Laevis ◽  
Atp Synthase ◽  
Xenopus Laevis Oocytes ◽  
Proton Pumps ◽  
Thiol Oxidation ◽  
Protein Thiol ◽  
Complex Iv ◽  
Subunit C ◽  
Catalyst Free ◽  
Mitochondrial Atp Synthase

Oocytes are postulated to repress the proton pumps (e.g., complex IV) and ATP synthase to safeguard mitochondrial DNA homoplasmy by curtailing superoxide production. Whether the ATP synthase is inhibited is, however, unknown. Here we show that: oligomycin sensitive ATP synthase activity is significantly greater (~170 vs. 20 nmol/min−1/mg−1) in testes compared to oocytes in Xenopus laevis (X. laevis). Since ATP synthase activity is redox regulated, we explored a regulatory role for reversible thiol oxidation. If a protein thiol inhibits the ATP synthase, then constituent subunits must be reversibly oxidised. Catalyst-free trans-cyclooctene 6-methyltetrazine (TCO-Tz) immunocapture coupled to redox affinity blotting reveals several subunits in F1 (e.g., ATP-α-F1) and Fo (e.g., subunit c) are reversibly oxidised. Catalyst-free TCO-Tz Click PEGylation reveals significant (~60%) reversible ATP-α-F1 oxidation at two evolutionary conserved cysteine residues (C244 and C294) in oocytes. TCO-Tz Click PEGylation reveals ~20% of the total thiols in the ATP synthase are substantially oxidised. Chemically reversing thiol oxidation significantly increased oligomycin sensitive ATP synthase activity from ~12 to 100 nmol/min−1/mg−1 in oocytes. We conclude that reversible thiol oxidation inhibits the mitochondrial ATP synthase in X. laevis oocytes.

scholarly journals Lysine methylation of mitochondrial ATP synthase subunit c stored in tissues of dogs with hereditary ceroid lipofuscinosis

1994 ◽  
Vol 269 (13) ◽  
pp. 9906-9911
Author(s):  
M.L. Katz ◽  
J.S. Christianson ◽  
N.E. Norbury ◽  
C.L. Gao ◽  
A.N. Siakotos ◽  
...  
Keyword(s):  
Atp Synthase ◽  
Lysine Methylation ◽  
Subunit C ◽  
Ceroid Lipofuscinosis ◽  
Mitochondrial Atp Synthase

scholarly journals ATP synthase subunit c expression: physiological regulation of the P1 and P2 genes

1997 ◽  
Vol 323 (2) ◽  
pp. 379-385 ◽  
Author(s):  
Ulf ANDERSSON ◽  
Josef HOUŠTĚK ◽  
Barbara CANNON
Keyword(s):  
Thyroid Hormone ◽  
Cold Acclimation ◽  
Atp Synthase ◽  
Hormone Treatment ◽  
Rat Tissues ◽  
Mrna Levels ◽  
Subunit C ◽  
Brown Adipose ◽  
Mitochondrial Atp Synthase

Pre-translational regulation of subunit c has been suggested to control the biosynthesis of mitochondrial ATP synthase (ATPase) in brown adipose tissue (BAT). Subunit c is encoded by the genes P1 and P2, which encode identical mature proteins. We have determined here the levels of P1 and P2 mRNAs in different tissues, in response to cold acclimation in rats, during ontogenic development of BAT in hamsters, and following thyroid hormone treatment in rat BAT and liver. Quantitative ribonuclease protection analysis showed that both the P1 and P2 mRNAs were present in all rat tissues measured. Their total amount in each tissue corresponded well with the ATPase content of that tissue. While the P1/P2 mRNA ratio is high in ATPase-rich tissues, the P2 mRNA dominates in tissues with less ATPase. Cold acclimation affects P1 but not P2 gene expression in rat BAT. A rapid and transient increase in P1 mRNA is followed by sustained depression, which is accompanied by a decrease in ATPase content. Similarly, ontogenic suppression of ATPase content in hamster BAT was accompanied by suppression of the P1 mRNA levels, while P2 expression was virtually unchanged. Furthermore, when hypothyroid rats were treated with thyroid hormone, the steady-state level of P1 but not of P2 mRNA was significantly increased in liver. BAT was unaffected. We conclude that the P1 and P2 genes for subunit c are differentially regulated in vivo. While the P2 gene is expressed constitutively, the P1 gene responds to different physiological stimuli as a means of modulating the relative content of ATP synthase.

scholarly journals A critical appraisal of evidence for localized energy coupling. Kinetic studies on liposomes containing bacteriorhodopsin and ATP synthase

1985 ◽  
Vol 230 (2) ◽  
pp. 543-549 ◽  
Author(s):  
R L Van der Bend ◽  
J Petersen ◽  
J A Berden ◽  
K Van Dam ◽  
H V Westerhoff
Keyword(s):  
Electron Transfer ◽  
Atp Synthase ◽  
Critical Appraisal ◽  
Atp Synthesis ◽  
Kinetic Studies ◽  
Energy Coupling ◽  
Proton Pumps ◽  
Specific Interactions ◽  
Mitochondrial Atp Synthase ◽  
Different Levels

In intact systems (chloroplasts, mitochondria and bacteria) many experiments have been reported which are indicative of localized coupling between ATP synthase and electron transfer complexes. We have carried out similar experiments with a system in which we may assume that specific interactions between the proton pumps are absent: reconstituted vesicles containing bacteriorhodopsin and yeast mitochondrial ATP synthase. The only experiment that gives results which differ from those previously published for intact systems concerns the effect of uncouplers on the rate of ATP synthesis at different levels of inhibition of the ATP synthase. We propose that this type of experiment may discriminate between localized and delocalized coupling.

scholarly journals Lysosomal Storage of Subunit c of Mitochondrial ATP Synthase in Brain-Specific Atp13a2-Deficient Mice

2016 ◽  
Vol 186 (12) ◽  
pp. 3074-3082 ◽  
Author(s):  
Shigeto Sato ◽  
Masato Koike ◽  
Manabu Funayama ◽  
Junji Ezaki ◽  
Takahiro Fukuda ◽  
...  
Keyword(s):  
Atp Synthase ◽  
Lysosomal Storage ◽  
Subunit C ◽  
Mitochondrial Atp Synthase ◽  
Deficient Mice

scholarly journals Characterization of the expressed genes for subunit c of mitochondrial ATP synthase in sheep with ceroid lipofuscinosis

1993 ◽  
Vol 293 (1) ◽  
pp. 65-73 ◽  
Author(s):  
S M Medd ◽  
J E Walker ◽  
R D Jolly
Keyword(s):  
Atp Synthase ◽  
Mitochondrial Targeting ◽  
Mitochondrial Import ◽  
Fragment Analysis ◽  
Subunit C ◽  
Ceroid Lipofuscinosis ◽  
Mitochondrial Atp Synthase ◽  
C Subunit ◽  
Healthy Control

The human and bovine genomes each contain two expressed nuclear genes, called P1 and P2, for subunit c, a hydrophobic subunit of the membrane sector, Fo, of mitochondrial ATP synthase. Both P1 and P2 encode the same mature protein, but the associated mitochondrial import sequences are different. In sheep with the neurodegenerative disease ceroid lipofuscinosis, and also in humans with Batten's disease, unmodified subunit c accumulates in lysosome-derived organelles in a variety of tissues. However, the sequences of cDNAs for P1 and P2 from sheep with ceroid lipofuscinosis were identical to those in healthy control animals. Therefore, since there was no mutation in either of the mitochondrial import sequences of subunit c in the diseased animals, ceroid lipofuscinosis does not arise from changes in an import sequence causing mis-targeting of the c subunit to lysosomes. The levels of expression of P1 and P2 genes were approximately the same in diseased and healthy animals, and so the protein is unlikely to accumulate because of excessive transcription of either gene. Transcription of a spliced pseudogene related to P2 was detected in both a control animal and a sheep with ceroid lipofuscinosis. The transcripts encode amino acids 1-31 of the P2 mitochondrial targeting sequence. In the diseased animal, an arginine replaced a glutamine in the control sequence. However, restriction fragment analysis of genomic DNA from a further 12 sheep established that the sequence differences were not linked to ceroid lipofuscinosis.

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