Oxidative phosphorylation in yeast VI. ATPase activity and protein synthesis in mitochondria isolated from nuclear mutants deficient in cytochromes

1970 ◽  
Vol 205 (3) ◽  
pp. 513-519 ◽  
Author(s):  
J. Šubík ◽  
Š. Kužela ◽  
J. Kolarov ◽  
L. Kováč ◽  
T.M. Lachowicz
Keyword(s):  
Protein Synthesis ◽  
Oxidative Phosphorylation ◽  
Atpase Activity

scholarly journals Partial diploids of Escherichia coli carrying normal and mutant alleles affecting oxidative phosphorylation

1977 ◽  
Vol 162 (3) ◽  
pp. 665-670 ◽  
Author(s):  
F Gibson ◽  
G B Cox ◽  
J A Downie ◽  
J Radik
Keyword(s):  
Escherichia Coli ◽  
Fluorescence Quenching ◽  
Oxidative Phosphorylation ◽  
Atpase Activity ◽  
Adenosine Triphosphatase ◽  
Growth Yields ◽  
Normal Allele ◽  
Adenosine Triphosphatase Activity

A plasmid was isolated which included the region of the Escherichia coli chromosome carrying the known genes concerned with oxidative phosphorylation (unc genes). This plasmid was used to prepare partial diploids carrying normal unc alleles on the episome and one of the three mutant alleles (unc A401, uncB402 or unc-405) on the chromosome. These strains were compared with segregants from which the plasmid had been lost. Dominance of either normal ormutant unc alleles was determined by growth on succinate, growth yields on glucose, Mg-ATPase (Mg2+-stimulated adenosine triphosphatase) activity, atebrin-fluorescence quenching, ATP-dependent transhydrogenase activity and oxidative phosphorylation. In all the above tests, dominance of the normal allele was observed. However, in membranes from the diploid strains which carried a normal allele and either of the mutant alleles affecting Mg-ATPase activity (uncA401 or unc-405), the energy-linked functions were only partially restored.

Action of adenosine on energetics, protein synthesis and K(+) homeostasis in teleost hepatocytes

2000 ◽  
Vol 203 (17) ◽  
pp. 2657-2665 ◽  
Author(s):  
G. Krumschnabel ◽  
C. Biasi ◽  
W. Wieser
Keyword(s):  
Protein Synthesis ◽  
Oxygen Consumption ◽  
Atpase Activity ◽  
Oncorhynchus Mykiss ◽  
Carassius Auratus ◽  
Goldfish Carassius Auratus ◽  
Inhibition Of Protein Synthesis ◽  
Rate Of Oxygen Consumption ◽  
A1 Receptor ◽  
Lactate Formation

In a comparative study, we analysed the effects of adenosine on the energetics, protein synthesis and K(+)homeostasis of hepatocytes from the anoxia-tolerant goldfish Carassius auratus and the anoxia-intolerant trout Oncorhynchus mykiss. The rate of oxygen consumption did not respond immediately to the addition of adenosine to the cells from either species, but showed a significant decrease in trout hepatocytes after 30 min. The anaerobic rate of lactate formation was not significantly affected by adenosine in goldfish hepatocytes, but was increased in trout cells. We also studied the effects of adenosine on the two most prominent ATP consumers in these cells, protein synthesis and Na(+)/K(+)-ATPase activity. Under aerobic conditions, adenosine inhibited protein synthesis of hepatocytes from goldfish by 51% and of hepatocytes from trout by 32%. During anoxia, the rate of protein synthesis decreased by approximately 50% in goldfish hepatocytes and by 90% in trout hepatocytes, and this decrease was not altered by the presence of adenosine. Adenosine inhibited normoxic Na(+)/K(+)-ATPase activity and K(+)efflux by 20–35% in the cells of both species. An investigation into the mechanism underlying the inhibition of protein synthesis by adenosine indicated that, in the goldfish cells, adenosine acts via a membrane receptor-mediated pathway, i.e. the effect of adenosine was abolished by applying the A1 receptor antagonist 8-phenyltheophylline. In the trout, however, the uptake of adenosine into hepatocytes seems to be required for an effect on protein synthesis. [Ca(2+)](i) does not seem to be involved in the inhibition of protein synthesis by adenosine.

scholarly journals Prenatal Androgenization Alters the Development of GnRH Neuron and Preoptic Area RNA Transcripts in Female Mice

Endocrinology ◽  
2020 ◽  
Vol 161 (11) ◽  
Author(s):  
Laura L Burger ◽  
Elizabeth R Wagenmaker ◽  
Chayarndorn Phumsatitpong ◽  
David P Olson ◽  
Suzanne M Moenter
Keyword(s):  
Protein Synthesis ◽  
Oxidative Phosphorylation ◽  
Polycystic Ovary ◽  
Affinity Purification ◽  
Developmental Trajectory ◽  
Late Gestation ◽  
Gnrh Neuron ◽  
Altered Expression ◽  
Increased Risk ◽  
Gnrh Neurons

Abstract Polycystic ovary syndrome (PCOS) is the most common form of infertility in women. The causes of PCOS are not yet understood and both genetics and early-life exposure have been considered as candidates. With regard to the latter, circulating androgens are elevated in mid–late gestation in women with PCOS, potentially exposing offspring to elevated androgens in utero; daughters of women with PCOS are at increased risk for developing this disorder. Consistent with these clinical observations, prenatal androgenization (PNA) of several species recapitulates many phenotypes observed in PCOS. There is increasing evidence that symptoms associated with PCOS, including elevated luteinizing hormone (LH) (and presumably gonadotropin-releasing hormone [GnRH]) pulse frequency emerge during the pubertal transition. We utilized translating ribosome affinity purification coupled with ribonucleic acid (RNA) sequencing to examine GnRH neuron messenger RNAs from prepubertal (3 weeks) and adult female control and PNA mice. Prominent in GnRH neurons were transcripts associated with protein synthesis and cellular energetics, in particular oxidative phosphorylation. The GnRH neuron transcript profile was affected more by the transition from prepuberty to adulthood than by PNA treatment; however, PNA did change the developmental trajectory of GnRH neurons. This included families of transcripts related to both protein synthesis and oxidative phosphorylation, which were more prevalent in adults than in prepubertal mice but were blunted in PNA adults. These findings suggest that prenatal androgen exposure can program alterations in the translatome of GnRH neurons, providing a mechanism independent of changes in the genetic code for altered expression.

scholarly journals Protein kinase C-α inhibits the repair of oxidative phosphorylation after S-(1,2-dichlorovinyl)-l-cysteine injury in renal cells

2004 ◽  
Vol 287 (1) ◽  
pp. F64-F73 ◽  
Author(s):  
Xiuli Liu ◽  
Malinda L. Godwin ◽  
Grażyna Nowak
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Oxidative Phosphorylation ◽  
Atpase Activity ◽  
Mitochondrial Function ◽  
Recovery Period ◽  
Β Subunit ◽  
Atp Production ◽  
Kinase C ◽  
Mitochondrial Functions

Previously, we showed that physiological functions of renal proximal tubular cells (RPTC) do not recover following S-(1,2-dichlorovinyl)-l-cysteine (DCVC)-induced injury. This study investigated the role of protein kinase C-α (PKC-α) in the lack of repair of mitochondrial function in DCVC-injured RPTC. After DCVC exposure, basal oxygen consumption (Qo2), uncoupled Qo2, oligomycin-sensitive Qo2, F1F0-ATPase activity, and ATP production decreased, respectively, to 59, 27, 27, 57, and 68% of controls. None of these functions recovered. Mitochondrial transmembrane potential decreased 53% after DCVC injury but recovered on day 4. PKC-α was activated 4.3- and 2.5-fold on days 2 and 4, respectively, of the recovery period. Inhibition of PKC-α activation (10 nM Go6976) did not block DCVC-induced decreases in mitochondrial functions but promoted the recovery of uncoupled Qo2, oligomycin-sensitive Qo2, F1F0-ATPase activity, and ATP production. Protein levels of the catalytic β-subunit of F1F0-ATPase were not changed by DCVC or during the recovery period. Amino acid sequence analysis revealed that α-, β-, and ε-subunits of F1F0-ATPase have PKC consensus motifs. Recombinant PKC-α phosphorylated the β-subunit and decreased F1F0-ATPase activity in vitro. Serine but not threonine phosphorylation of the β-subunit was increased during late recovery following DCVC injury, and inhibition of PKC-α activation decreased this phosphorylation. We conclude that during RPTC recovery following DCVC injury, 1) PKC-α activation decreases F0F1-ATPase activity, oxidative phosphorylation, and ATP production; 2) PKC-α phosphorylates the β-subunit of F1F0-ATPase on serine residue; and 3) PKC-α does not mediate depolarization of RPTC mitochondria. This is the first report showing that PKC-α phosphorylates the catalytic subunit of F1F0-ATPase and that PKC-α plays an important role in regulating repair of mitochondrial function.

scholarly journals LIGAND-INDUCED MOVEMENT OF LYMPHOCYTE MEMBRANE MACROMOLECULES

1973 ◽  
Vol 137 (3) ◽  
pp. 675-689 ◽  
Author(s):  
Emil R. Unanue ◽  
Morris J. Karnovsky ◽  
Howard D. Engers
Keyword(s):  
Protein Synthesis ◽  
Cell Membrane ◽  
Cell Surface ◽  
Oxidative Phosphorylation ◽  
Cross Linking ◽  
Lymphocyte Membrane ◽  
Compact Zone ◽  
Entire Cell ◽  
Freeze Etching ◽  
Spleen Lymphocytes

Spleen lymphocytes were studied for the movement and interiorization of complexes of anti-Ig-surface Ig. The movement of the complex into a small, compact zone of the cell membrane (forming a cap) was inhibited by drugs that inhibited glycolysis and oxidative phosphorylation, but not by drugs that affected protein synthesis. Dead lymphocytes did not form caps. Freeze-etching techniques revealed that inhibited lymphocytes showed formation of multiple small complexes over the entire cell surface. Inhibitors of glycolysis and of oxidative phosphorylation also inhibited the interiorization and catabolism of radioiodinated anti-Ig. We hypothesize that cross-linking of all the surface Ig triggers the membrane movements that are required to pull the lattice into one zone of the cell.

scholarly journals Ribosome-Dependent ATPase Interacts with Conserved Membrane Protein in Escherichia coli to Modulate Protein Synthesis and Oxidative Phosphorylation

PLoS ONE ◽  
2011 ◽  
Vol 6 (4) ◽  
pp. e18510 ◽  
Author(s):  
Mohan Babu ◽  
Hiroyuki Aoki ◽  
Wasimul Q. Chowdhury ◽  
Alla Gagarinova ◽  
Chris Graham ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Protein Synthesis ◽  
Membrane Protein ◽  
Oxidative Phosphorylation ◽  
Dependent Atpase

O2 affinity of cross-linked hemoglobins modifies O2 metabolism in proximal tubules

2003 ◽  
Vol 95 (2) ◽  
pp. 563-570 ◽  
Author(s):  
A. D. Baines ◽  
P. Ho
Keyword(s):  
Oxidative Phosphorylation ◽  
Atpase Activity ◽  
Proximal Tubule ◽  
Diamine Oxidase ◽  
Proximal Tubules ◽  
Facilitated Diffusion ◽  
Atp Content ◽  
Saturation Point ◽  
Binding Characteristics ◽  
Isolated Rat

Previous experiments using cross-linked tetrameric hemoglobins (XLHb) to perfuse isolated rat kidneys showed that high-O2-affinity XLHb improved proximal tubule function more effectively than low-O2-affinity XLHb. To determine how function was improved, proximal tubule fragments were incubated with albumin, Hb34 [half-saturation point (P50) 34 Torr], or Hb13 (P50 13 Torr) with Po2 values ranging from 22 to 147 Torr. ATP content reflected O2 delivery to mitochondria. Both XLHb increased ATP, Hb34 with Po2 ≥ 47 Torr and Hb13 with Po2 ≤ 47 Torr. XLHb increased Na-K-ATPase activity (86Rb uptake) in similar Po2-dependent patterns. O2 consumption (Q̇o2) was measured in a closed, well-stirred chamber. Ouabain- and oligomycin-inhibited Q̇o2, reflecting Na-K-ATPase activity and oxidative phosphorylation, respectively, mirrored the Po2-dependent patterns of ATP and 86Rb uptake. As Po2 fell below the midpoint of XLHb desaturation, Q̇o2, uncoupled from oxidative phosphorylation, transiently increased. The increase was most pronounced with Hb34. Nitro-l-arginine methyl ester had no effect on Q̇o2. Inhibitors of NAD(P)H oxidases and diamine oxidase partially prevented the Q̇o2 surge with Hb34. In conclusion, facilitated diffusion accounts for Po2-dependent XLHb effects on ATP content and Na-K-ATPase and for Hb13's effectiveness in hypoxic perfused kidneys. NO scavenging was not a factor. O2-binding characteristics influence XLHb effects on mitochondria and O2-sensitive enzymes such as oxidases.

Thyroid control over membrane processes in rat heart

1991 ◽  
Vol 261 (4) ◽  
pp. L66-L71
Author(s):  
Enn K. Seppet ◽  
Lumme Y. Kadaya ◽  
Tomoji Hata ◽  
Ants P. Kallikorm ◽  
Valdur A. Saks ◽  
...  
Keyword(s):  
Creatine Kinase ◽  
Oxidative Phosphorylation ◽  
Atpase Activity ◽  
Rat Heart ◽  
Transport Processes ◽  
Functional Coupling ◽  
Mitochondrial Creatine Kinase ◽  
Thyroid State ◽  
Hyperthyroid Heart ◽  
Pumping Activity

We have studied the effects of hypo- and hyperthyroidism on sarcolemmal (SL) and sarcoplasmic reticular (SR) ion transport processes and mitochondrial energy production in rat heart. The following conclusions were derived. 1) Compared with euthyroid state, hyperthyroidism led to increased SR Ca+-accumulation. In SL, the activities of Ca2+-stimulated adenosine triphosphatase (ATPase), ATP-dependent Ca+ pumping, and Na+-Ca2+ exchanger were not affected; but ouabain-sensitive Na+-K+-ATPase activity was enhanced. 2) Hypothyroidism resulted in depressed activities of Ca2+ pumps both in SL and SR. In SL, the Na+-K+-ATPase activity was decreased, but Na+-Ca2+ exchange was unaltered. 3) Thus slower relaxation of the hypothyroid myocardium may be attributed to depressed functioning of Ca2+ pumps in SR and SL, whereas faster relaxation of the hyperthyroid heart may be based on increased Ca2+-pumping activity of SR. 4) Hyperthyroidism and hypothyroidism, respectively, led to enhanced and decreased rates of mitochondrial phosphocreatine synthesis. The thyroid state appears to control the functional coupling between mitochondrial creatine kinase and ATP-ADP translocase: the energy of oxidative phosphorylation was transformed into phosphocreatine more effectively in mitochondria from hypothyroid hearts than in those from hyperthyroid hearts. euthyroid; hyperthyroid; hypothyroid; mitochondrial creatine kinase; myocardium; oxidative phosphorylation; phosphocreatine synthesis; sarcolemma; sarcoplasmic reticulum

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