pH-Sensitive Binding of Cytochromecto the Inner Mitochondrial Membrane. Implications for the Participation of the Protein in Cell Respiration and Apoptosis

Biochemistry ◽  
2009 ◽  
Vol 48 (35) ◽  
pp. 8335-8342 ◽  
Author(s):  
Cintia Kawai ◽  
Felipe S. Pessoto ◽  
Tiago Rodrigues ◽  
Katia C. U. Mugnol ◽  
Veronica Tórtora ◽  
...  
Keyword(s):  
Mitochondrial Membrane ◽  
Ph Sensitive ◽  
Cell Respiration ◽  
Inner Mitochondrial Membrane

scholarly journals Testing the carotenoid-based sexual signalling mechanism by altering CYP2J19 gene expression and colour in a bird species

2020 ◽  
Vol 287 (1938) ◽  
pp. 20201067
Author(s):  
Alejandro Cantarero ◽  
Pedro Andrade ◽  
Miguel Carneiro ◽  
Adrián Moreno-Borrallo ◽  
Carlos Alonso-Alvarez
Keyword(s):  
Resource Availability ◽  
Mitochondrial Membrane ◽  
Bird Species ◽  
Individual Quality ◽  
Cell Respiration ◽  
Inner Mitochondrial Membrane ◽  
Maintenance Costs ◽  
Trade Offs ◽  
Gene Coding ◽  
Sexual Signalling

Ornaments can evolve to reveal individual quality when their production/maintenance costs make them reliable as ‘signals’ or if their expression level is intrinsically linked to condition by some unfalsifiable mechanism (indices). The latter has been mostly associated with traits constrained by body size. In red ketocarotenoid-based colorations, that link could, instead, be established with cell respiration at the inner mitochondrial membrane (IMM). The production mechanism could be independent of resource (yellow carotenoids) availability, thus discarding costs linked to allocation trade-offs. A gene coding for a ketolase enzyme (CYP2J19) responsible for converting dietary yellow carotenoids to red ketocarotenoids has recently been described. We treated male zebra finches with an antioxidant designed to penetrate the IMM (mitoTEMPO) and a thyroid hormone (triiodothyronine) with known hypermetabolic effects. Among hormone controls, MitoTEMPO downregulated CYP2J19 in the bill (a red ketocarotenoid-based ornament), supporting the mitochondrial involvement in ketolase function. Both treatments interacted when increasing hormone dosage, indicating that mitochondria and thyroid metabolisms could simultaneously regulate coloration. Moreover, CYP2J19 expression was positively correlated to redness but also to yellow carotenoid levels in the blood. However, treatment effects were not annulated when controlling for blood carotenoid variability, which suggests that costs linked to resource availability could be minor.

scholarly journals A mitochondria-targeted antioxidant affects the carotenoid-based plumage of red crossbills

2019 ◽  
Author(s):  
Alejandro Cantarero ◽  
Rafael Mateo ◽  
Pablo Camarero ◽  
Daniel Alonso ◽  
Blanca Fernandez-Eslava ◽  
...  
Keyword(s):  
Mitochondrial Membrane ◽  
Blood Levels ◽  
Individual Quality ◽  
Cell Respiration ◽  
Synthetic Antioxidants ◽  
Inner Mitochondrial Membrane ◽  
Enzymatic Production ◽  
Quality Signals ◽  
Summary Statement ◽  
Red Crossbills

ABSTRACTThe mechanisms involved in the production of red carotenoid-based ornaments in vertebrates are still poorly understood. Those colours generated by red carotenoids often depend on the enzymatic production (ketolation) of these pigments from dietary yellow carotenoids. Recently, it has been proposed that this conversion takes place at the inner mitochondrial membrane (IMM). This implies that carotenoid ketolation and cell respiration could share the same biochemical pathways. Such a link would favour the evolution of red ketocarotenoid-based ornaments as reliable indices of individual quality under a sexual selection scenario. We exposed captive male red crossbills (Loxia curvirostra Linnaeus) to two different synthetic antioxidants designed to penetrate into the IMM: a synthetic ubiquinone (mitoQ) and a superoxide dismutase mimetic (mitoTEMPO). MitoQ decreased the blood levels of substrate yellow carotenoids and tocopherol. This could be attributed to the characteristics of the mitoQ molecule, which can distort the IMM structure, increasing free radical (superoxide) production and, potentially, antioxidant consumption. Contrarily, mitoTEMPO-treated birds increased the plasma levels of the second most abundant red ketocarotenoid of red crossbills (i.e. canthaxanthin). MitoTEMPO also increased plumage redness and total ketocarotenoid concentration in feathers among those birds exhibiting a redder plumage at the beginning of the study, rising the plasma values of the main red pigment (3-hydroxyechinenone) in paler birds. The results as a whole support the involvement of the mitochondrial antioxidant machinery in carotenoid biotransformation. The fact that the initial plumage redness determined the effect of mitoTEMPO suggests that the mitochondrial-based mechanism is intimately linked to individual quality.Summary statementAntioxidants designed to penetrate the mitochondrial membrane increased avian plumage redness but depending on pre-existing colouration. This supports mitochondrial involvement in the evolution of carotenoid-based ornaments as reliable quality signals.

Modulation of the calcium-activated BK-channel of the inner mitochondrial membrane by hypoxia

2007 ◽  
Vol 34 (S 2) ◽  
Author(s):  
D Siemen ◽  
Y Cheng ◽  
X Gu ◽  
P Bednarczyk ◽  
GG Haddad ◽  
...  
Keyword(s):  
Mitochondrial Membrane ◽  
Bk Channel ◽  
Inner Mitochondrial Membrane

The Efects of Spaceflight on Mitochondria in Human Lymphocytes (Jurkat).

1999 ◽  
Vol 5 (S2) ◽  
pp. 1118-1119
Author(s):  
Heide Schatten ◽  
Marian Lewis
Keyword(s):  
Mitochondrial Membrane ◽  
Space Shuttle ◽  
Human Lymphocytes ◽  
Jurkat Cells ◽  
Apoptotic Bodies ◽  
Inner Mitochondrial Membrane ◽  
Mitochondrial Alterations ◽  
Mitochondrial Volume ◽  
Number Of Cells ◽  
Related Increase

Spaceflight induced mitochondrial alterations have been reported for muscle and may be associated with altered physiological functions in space. Mitochondrial alterations are also indicative of preapoptotic events which are seen in greater amounts in cells exposed to spaceflight when compared with cells cultured at 1 g. Preapoptotic mitochondrial changes include alterations of processes at the inner mitochondrial membrane and can result in changes in mitochondrial volume. Higher amounts of oxidative stress during space flight may be one of the causes for changes which lead to apoptosis. Jurkat cells flown on the STS-76 space shuttle mission showed an increase in the number of cells with apoptotic bodies early in the mission and a time-dependent, microgravity-related increase in the Fas/APO-1 cell death factor. Here we investigated the morphology of mitochondria in Jurkat cells exposed to spaceflight during the STS-76 mission.

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