scholarly journals Ferrochelatase and δ-aminolaevulate synthetase in brain, heart, kidney and liver of normal and porphyric rats. The induction of δ-aminolaevulate synthetase in kidney cytosol and mitochondria by allylisopropylacetamide

1971 ◽  
Vol 124 (3) ◽  
pp. 633-637 ◽  
Author(s):  
R. Barnes ◽  
M. S. Jones ◽  
O. T. G. Jones ◽  
R. J. Porra
Keyword(s):  
Glutamate Dehydrogenase ◽  
Brain Mitochondria ◽  
Cytosol Fraction ◽  
Kidney Mitochondria ◽  
Liver And Kidney ◽  
Cytochrome Content

1. δ-Aminolaevulate synthetase was detected in liver and kidney mitochondria prepared from normal rats. 2. The administration of allylisopropylacetamide induced an increase in δ-aminolaevulate synthetase in both liver and kidney mitochondria and the enzyme also appeared in the cytosol fraction of both tissues. Comparison with the distribution of glutamate dehydrogenase indicated that this soluble kidney δ-aminolaevulate synthetase was truly of cytosol origin and did not arise from disrupted mitochondria. The kidney cytosol enzyme was inhibited by 50% by 50μm-protohaem. 3. δ-Aminolaevulate synthetase could not be detected in mitochondria or cytosol from heart or brain from normal or porphyric rats. 4. The administration of allylisopropylacetamide caused little or no increase in ferrochelatase or cytochrome content of liver, kidney, heart or brain mitochondria.

scholarly journals Regulation of mitochondrial protein turnover by thyroid hormone(s)

1975 ◽  
Vol 152 (2) ◽  
pp. 379-387 ◽  
Author(s):  
Medha S. Rajwade ◽  
Surendra S. Katyare ◽  
Prema Fatterpaker ◽  
Arunachala Sreenivasan
Keyword(s):  
Thyroid Hormone ◽  
Protein Turnover ◽  
Mitochondrial Protein ◽  
Brain Mitochondria ◽  
Mitochondrial Proteins ◽  
Proteinase Activity ◽  
Turnover Rates ◽  
Kidney Mitochondria ◽  
Liver And Kidney ◽  
Protein Components

1. The effect of thyroidectomy on turnover rates of liver, kidney and brain mitochondrial proteins was examined. 2. In the euthyroid state, liver and kidney mitochondria show a synchronous turnover with all protein components showing more or less identical half-lives compared with the whole mitochondria. The brain mitochondrial proteins show asynchronous turnover, the soluble proteins having shorter half-lives. 3. Mitochondrial DNA (m-DNA) of liver and kidney has half-lives comparable with that of whole mitochondria from these tissues. 4. Thyroidectomy results in increased half-lives of liver and kidney mitochondria, with no apparent change in the half-life of brain mitochondria. 5. A detailed investigation of the turnover rates of several protein components revealed a significant decrease in the turnover rates of mitochondrial insoluble proteins from the three tissues under study. 6. The turnover rates of m-DNA of liver and kidney show a parallel decrease. 7. Thus it is apparent that thyroid hormone(s) may have a regulatory role in maintaining the synchrony of turnover of liver and kidney mitochondria in the euthyroid state. Turnover of brain mitochondria may perhaps be regulated by some other factor(s) in addition to thyroid hormone(s). 8. It seems likely that during mitochondrial turnover m-DNA and insoluble proteins may constitute a major unit. 9. The mitochondrial protein contents of the three tissues are not affected by thyroidectomy. 10. No correlation was seen between the turnover rate of mitochondria and cathepsin activity in any of the tissues under study in normal or thyroidectomized animals. 11. On the other hand, mitochondrial proteinase activity shows good correlation with the turnover rates of mitochondria in normal animals, and a parallel decrease in activity comparable with the decreased rates of turnover is observed after thyroidectomy. 12. It is concluded that mitochondrial proteinase activity may play a significant role in their protein turnover.

Effects of protamine and strophanthin on mitochondrial potassium, sodium and water

1960 ◽  
Vol 199 (4) ◽  
pp. 653-656
Author(s):  
Leonard Share
Keyword(s):  
Rat Liver ◽  
Sodium Concentration ◽  
Water Metabolism ◽  
Intact Cells ◽  
Kidney Mitochondria ◽  
Potassium Sodium ◽  
Isolated Mitochondria ◽  
Liver And Kidney ◽  
Uncoupling Of Oxidative Phosphorylation ◽  
High Concentrations

A study was made of the effects of certain agents, which inhibit potassium transport in intact cells, on the potassium, sodium and water metabolism of isolated mitochondria. Protamine (4 mg/100 ml) induced swelling in rat liver and kidney mitochondria and impaired the ability of these mitochondria to concentrate potassium. These actions appeared to be associated with the uncoupling of oxidative phosphorylation. Protamine was without effect on the mitochondrial sodium concentration. Strophanthin at extremely high concentrations (1 gm/100 ml) was also found to induce swelling of rat liver, kidney and heart mitochondria and to interfere with the ability of the mitochondria to concentrate potassium. There was a tendency for mitochondrial sodium concentration to be elevated. It is concluded that the actions of protamine and strophanthin on mitochondria are qualitatively and quantitatively different from the actions of these substances on intact cells and that there are basic differences between the potassium concentrating mechanisms in mitochondria and in intact cells.

STUDIES OF FATTY ACID OXIDATION: 4. THE EFFECTS OF FATTY ACIDS ON THE OXIDATION OF OTHER METABOLITES

1956 ◽  
Vol 34 (6) ◽  
pp. 1211-1225 ◽  
Author(s):  
P. G. Scholefield
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Respiratory Activity ◽  
Tricarboxylic Acid Cycle ◽  
Rat Kidney ◽  
Brain Mitochondria ◽  
Acid Oxidation ◽  
Inhibitory Effects ◽  
Kidney Mitochondria ◽  
Low Concentrations

Fatty acids inhibit the oxidation of pyruvate by rat-kidney mitochondria but the extent of inhibition depends upon the nature and amount of agent added to stimulate the oxidation. The longer chain fatty acids are more effective inhibitors and, in general, the even-numbered fatty acids show greater inhibitory effects than the adjacent odd-numbered fatty acids. Under conditions where 2, 4-dinitrophenol (DNOP) and the fatty acids separately have little effect on the respiratory activity of rat-kidney mitochondria with pyruvate as substrate, the addition of both fatty acid and DNOP results in an extensive inhibition. At low concentrations the fatty acids are oxidized by rat-kidney mitochondria but at concentrations of 10−3 M and higher they inhibit their own oxidation, the oxidation of pyruvate, and those of the acids of the tricarboxylic acid cycle. The oxidation of pyruvate by rat-brain mitochondria is insensitive to decanoate but both the fumarate- and DNOP-stimulated oxidations of pyruvate are sensitive to the presence of decanoate. In contrast, Nembutal inhibits both the oxidation of pyruvate alone and the fumarate-stimulated oxidation of pyruvate. Possible mechanisms for the observed inhibitory effects of fatty acids are discussed.

scholarly journals Is respiratory activity in the brain mitochondria responsive to thyroid hormone action?: a critical re-evaluation

1994 ◽  
Vol 302 (3) ◽  
pp. 857-860 ◽  
Author(s):  
S S Katyare ◽  
C S Bangur ◽  
J L Howland
Keyword(s):  
Thyroid Hormone ◽  
Malate Dehydrogenase ◽  
Respiratory Activity ◽  
Hormone Treatment ◽  
Brain Mitochondria ◽  
Dependent Manner ◽  
Glutamate Pyruvate ◽  
Activity State ◽  
Cytochrome Content

The effects of in vivo treatment with graded doses (0.5-1.5 micrograms/g body weight) of thyroid hormones, tri-iodothyronine (T3) and thyroxine (T4), for 4 consecutive days to euthyroid rats on the respiratory activity of isolated brain mitochondria were examined. T4 stimulated coupled State-3 respiration with glutamate, pyruvate + malate, ascorbate + tetramethyl-p-phenylenediamine and succinate, in a dose-dependent manner; T3 was effective only at the highest (1.5 micrograms) dose employed. T4 was more effective than T3 in stimulating respiratory activity. State-4 respiratory rates were in general not influenced except in the case of the ascorbate + tetramethyl-p-phenylenediamine system. Primary dehydrogenase activities, i.e. glutamate dehydrogenase, malate dehydrogenase and succinate dehydrogenase, were stimulated about 2-fold; interestingly mitochondrial but not cytosolic malate dehydrogenase activity was influenced under these conditions. The hormone treatments did not greatly influence the mitochondrial cytochrome content. The results therefore suggest that thyroid hormone treatment not only stimulates primary dehydrogenase activities but may also directly influence the process of mitochondrial electron transfer.

Purification and Properties of α-Aminoadipate Aminotransferase from Rat Liver and Kidney Mitochondria

1991 ◽  
Vol 21 (2-3) ◽  
pp. 151-162 ◽  
Author(s):  
Madhumalti R. Mawal ◽  
Arindam Mukhopadhyay ◽  
Devendra R. Deshmukh
Keyword(s):  
Rat Liver ◽  
Kidney Mitochondria ◽  
Purification And Properties ◽  
Liver And Kidney

THE UPTAKE OF GLYCINE BY RAT BRAIN MITOCHONDRIA

1965 ◽  
Vol 43 (7) ◽  
pp. 1119-1127 ◽  
Author(s):  
T. Nukada
Keyword(s):  
Amino Acids ◽  
Rat Brain ◽  
Structural Integrity ◽  
Brain Mitochondria ◽  
Sodium Ions ◽  
Glycine Uptake ◽  
Kidney Mitochondria ◽  
Rat Brain Mitochondria ◽  
Sodium Dependent

Rat brain mitochondrial pellets are able to accumulate glycine by a sodium-dependent and ouabain-sensitive process which is not potassium dependent. This process does not occur in liver or kidney mitochondria. Glycine uptake by brain mitochondria is not affected by the addition of ATP, NAD, or other cofactors, but it is inhibited by dinitrophenol and, competitively, by certain amino acids. Data obtained by the use of various concentrations of sodium ions or of sucrose indicate that the uptake of glycine by brain mitochondria is closely linked with their structural integrity.

scholarly journals Mieap forms membraneless organelles to compartmentalize and facilitate cardiolipin metabolism

2020 ◽  
Author(s):  
Naoki Ikari ◽  
Katsuko Honjo ◽  
Yoko Sagami ◽  
Yasuyuki Nakamura ◽  
Hirofumi Arakawa
Keyword(s):  
Quality Control ◽  
Critical Role ◽  
Enzymatic Reactions ◽  
Liquid Droplets ◽  
Inner Mitochondrial Membrane ◽  
Mitochondrial Quality Control ◽  
Kidney Mitochondria ◽  
Intrinsically Disordered ◽  
Liver And Kidney ◽  
Inducible Protein

AbstractLiquid droplets function as membraneless organelles that compartmentalize and facilitate efficient biological reactions in cells. They are formed by proteins with an intrinsically disordered region(s) (IDR) via liquid–liquid phase separation. Mieap/SPATA18, a p53-inducible protein, plays a critical role in the suppression of human and murine colorectal tumors via mitochondrial quality control. However, the regulatory mechanism underlying this process remains unclear. Here, we report that Mieap is an IDR-containing protein that drives the formation of liquid droplets in the mitochondria. Mieap liquid droplets (MLDs) specifically phase separate the mitochondrial phospholipid cardiolipin. Lipidomic analysis of cardiolipin suggested that Mieap promotes enzymatic reactions involved in cardiolipin metabolism, including biosynthesis and remodeling. Accordingly, four cardiolipin biosynthesis enzymes, TAMM41, PGS1, PTPMT1, and CRLS1, and two remodeling enzymes, PLA2G6 and TAZ, are phase separated by MLDs. Mieap-deficient mice exhibited altered cristae structure in the liver and kidney mitochondria and a trend of obesity. These results suggest that Mieap drives the formation of membraneless organelles to compartmentalize and promotes cardiolipin metabolism at the inner mitochondrial membrane, thus playing a possible role in mitochondrial quality control.

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