Frataxin Acts as an Iron Chaperone Protein to Modulate Mitochondrial Aconitase Activity

Science ◽  
2004 ◽  
Vol 305 (5681) ◽  
pp. 242-245 ◽  
Author(s):  
A.-L. Bulteau
Keyword(s):  
Aconitase Activity ◽  
Chaperone Protein ◽  
Mitochondrial Aconitase ◽  
Iron Chaperone

On the molecular relationships between high-zinc tolerance and aconitase (Aco1) in Saccharomyces cerevisiae

Metallomics ◽  
2014 ◽  
Vol 6 (3) ◽  
pp. 634-645 ◽  
Author(s):  
Maria Guirola ◽  
Elena Jiménez-Martí ◽  
Silvia Atrian
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Zinc Tolerance ◽  
Aconitase Activity ◽  
Mitochondrial Aconitase ◽  
High Zinc ◽  
Sensor Signals ◽  
Molecular Relationships

In yeast, the lack of mitochondrial aconitase activity determines high-zinc tolerance, which is accompanied by the alteration of several low-iron sensor signals.

Chaperone protein involved in transmembrane transport of iron

2014 ◽  
Vol 462 (1) ◽  
pp. 25-37 ◽  
Author(s):  
Izumi Yanatori ◽  
Yumiko Yasui ◽  
Mitsuaki Tabuchi ◽  
Fumio Kishi
Keyword(s):  
Binding Protein ◽  
Transmembrane Transport ◽  
Chaperone Protein ◽  
Iron Chaperone

Iron-associated DMT1 can interact with poly(rC)-binding protein 2 (PCBP2), although iron-chelated DMT1 cannot. PCBP2 can transfer Fe2+ from DMT1 to the appropriate sites or to ferroportin as an iron chaperone.

Effect of exogenous and endogenous nitric oxide on mitochondrial respiration of rat hepatocytes

1991 ◽  
Vol 260 (5) ◽  
pp. C910-C916 ◽  
Author(s):  
J. Stadler ◽  
T. R. Billiar ◽  
R. D. Curran ◽  
D. J. Stuehr ◽  
J. B. Ochoa ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Rat Hepatocytes ◽  
Significant Inhibition ◽  
Short Exposure ◽  
Aconitase Activity ◽  
Ubiquinone Oxidoreductase ◽  
Transport Chain ◽  
Mitochondrial Aconitase ◽  
Dependent Inhibition ◽  
Endogenous Nitric Oxide

Although nitric oxide (.N = O) biosynthesis is inducible in rat hepatocytes (HC), the physiological significance of .N = O production by these cells is unknown. Short exposure of HC to authentic .N = O led to a concentration-dependent inhibition of mitochondrial aconitase, NADH-ubiquinone oxidoreductase, and succinate-ubiquinone oxidoreductase (complexes I and II of the mitochondrial electron transport chain). Most susceptible to .N = O inhibition was mitochondrial aconitase, in which a reduction in enzyme activity to 20.2 +/- 1.6% of control was observed. In contrast to mitochondrial aconitase, cytosolic aconitase activity was not inhibited by .N = O. After exposure to a maximal inhibitory concentration of .N = O, mitochondrial aconitase activity recovered completely within 6 h. Complex I did not fully recover within this incubation period. Endogenous .N = O biosynthesis was induced in HC by a specific combination of cytokines and lipopolysaccharide. After 18 h of incubation with these stimuli, a significant inhibition of mitochondrial aconitase activity to 70.8 +/- 2.4% of controls was detected. However, this was due only in part to the action of .N = O. A non- .N = O-dependent inhibition of mitochondrial function appeared to be mediated by tumor necrosis factor.

scholarly journals Lack of aconitase in glyoxysomes and peroxisomes

1993 ◽  
Vol 294 (1) ◽  
pp. 103-107 ◽  
Author(s):  
F Courtois-Verniquet ◽  
R Douce
Keyword(s):  
Solanum Tuberosum ◽  
Potato Tuber ◽  
Castor Bean ◽  
Ricinus Communis ◽  
Glyoxylate Cycle ◽  
Plant Cells ◽  
Cytosol Fraction ◽  
Aconitase Activity ◽  
Mitochondrial Aconitase ◽  
The Glyoxylate Cycle

The aim of this work was to find out whether aconitase [citrate (isocitrate) hydro-lyase, EC 4.2.1.3] which is rapidly inactivated by H2O2, is present in the microbodies from plant cells. The separation of intact organelles from castor-bean (Ricinus communis) endosperm and potato (Solanum tuberosum) tuber indicated that aconitase activity is essentially limited to the mitochondria and cytosol fraction, but was not detected in highly purified castor-bean endosperm and potato tuber peroxisomes. An isotropic e.p.r. signal of the type expected for the 3Fe cluster of oxidized aconitase was not detected in microbodies. In immunoblot analyses, antibodies raised against potato tuber mitochondrial aconitase did not cross-react with any glyoxysomal or peroxisomal protein. Positive reactions were found for cytosol fraction and mitochondria of castor-bean endosperm. The operation of the full glyoxylate cycle in isolated glyoxysomes requires the presence of aconitase in the incubation medium. It is concluded that glyoxysomes are probably devoid of aconitase and that the glyoxylate cycle requires a detour via the cytosol, which contains a powerful aconitase activity.

The Iron Chaperone Protein CyaY from Vibrio cholerae Is a Heme-Binding Protein

Biochemistry ◽  
2017 ◽  
Vol 56 (18) ◽  
pp. 2425-2434 ◽  
Author(s):  
Takeshi Uchida ◽  
Noriyuki Kobayashi ◽  
Souichiro Muneta ◽  
Koichiro Ishimori
Keyword(s):  
Vibrio Cholerae ◽  
Binding Protein ◽  
Heme Binding ◽  
Chaperone Protein ◽  
Heme Binding Protein ◽  
Iron Chaperone

Heat shock-induced attenuation of hydroxyl radical generation and mitochondrial aconitase activity in cardiac H9c2 cells

2006 ◽  
Vol 290 (2) ◽  
pp. C313-C324 ◽  
Author(s):  
Govindasamy Ilangovan ◽  
C. D. Venkatakrishnan ◽  
Anna Bratasz ◽  
Sola Osinbowale ◽  
Arturo J. Cardounel ◽  
...  
Keyword(s):  
Heat Shock ◽  
Manganese Superoxide Dismutase ◽  
Shock Treatment ◽  
H9c2 Cells ◽  
Heat Shock Treatment ◽  
Irreversible Damage ◽  
Aconitase Activity ◽  
Mitochondrial Aconitase ◽  
Shock Proteins ◽  
Mnsod Activity

A mild heat shock (hyperthermia) protects cells from apoptotic and necrotic deaths by inducing overexpression of various heat shock proteins (Hsps). These proteins, in combination with the activation of the nitric oxide synthase (NOS) enzyme, play important roles in the protection of the myocardium against a variety of diseases. In the present work we report that the generation of potent reactive oxygen species (ROS), namely ·OH in cardiac H9c2 cells, is attenuated by heat shock treatment (2 h at 42°C). Western blot analyses showed that heat shock treatment induced overexpression of Hsp70, Hsp60, and Hsp25. The observed ·OH was found to be derived from the superoxide (O2−·) generated by the mitochondria. Whereas the manganese superoxide dismutase (MnSOD) activity was increased in the heat-shocked cells, the mitochondrial aconitase activity was reduced. The mechanism of O2−· conversion into ·OH in mitochondria is proposed as follows. The O2−· leaked from the electron transport chain, oxidatively damages the mitochondrial aconitase, releasing a free Fe2+. The aconitase-released Fe2+ combines with H2O2 to generate ·OH via a Fenton reaction and the oxidized Fe3+ recombines with the inactivated enzyme after being reduced to Fe2+ by other cellular reductants, turning it over to be active. However, in heat-shocked cells, because of higher MnSOD activity, the excess H2O2 causes irreversible damage to the mitochondrial aconitase enzyme, thus inhibiting its activity. In conclusion, we propose that attenuation of ·OH generation after heat shock treatment might play an important role in reducing the myocardial ischemic injury, observed in heat shock-treated animals.

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