scholarly journals A defect in the mitochondrial complex III, but not complex IV, triggers early ROS-dependent damage in defined brain regions

2012 ◽  
Vol 21 (23) ◽  
pp. 5066-5077 ◽  
Author(s):  
Francisca Diaz ◽  
Sofia Garcia ◽  
Kyle R. Padgett ◽  
Carlos T. Moraes
Keyword(s):  
Brain Regions ◽  
Complex Iii ◽  
Mitochondrial Complex ◽  
Complex Iv

scholarly journals Atomic structures of respiratory complex III2, complex IV, and supercomplex III2-IV from vascular plants

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Maria Maldonado ◽  
Fei Guo ◽  
James A Letts
Keyword(s):  
Vascular Plants ◽  
Proton Translocation ◽  
Complex Iii ◽  
Conformational Heterogeneity ◽  
Mitochondrial Matrix ◽  
Mitochondrial Complex ◽  
Complex Iv ◽  
Atomic Structures ◽  
Iron Sulfur ◽  
Heterogeneity Analysis

Mitochondrial complex III (CIII2) and complex IV (CIV), which can associate into a higher-order supercomplex (SC III2+IV), play key roles in respiration. However, structures of these plant complexes remain unknown. We present atomic models of CIII2, CIV, and SC III2+IV from Vigna radiata determined by single-particle cryoEM. The structures reveal plant-specific differences in the MPP domain of CIII2 and define the subunit composition of CIV. Conformational heterogeneity analysis of CIII2 revealed long-range, coordinated movements across the complex, as well as the motion of CIII2’s iron-sulfur head domain. The CIV structure suggests that, in plants, proton translocation does not occur via the H channel. The supercomplex interface differs significantly from that in yeast and bacteria in its interacting subunits, angle of approach and limited interactions in the mitochondrial matrix. These structures challenge long-standing assumptions about the plant complexes and generate new mechanistic hypotheses.

scholarly journals Differential responses of targeted lung redox enzymes to rat exposure to 60 or 85% oxygen

2011 ◽  
Vol 111 (1) ◽  
pp. 95-107 ◽  
Author(s):  
Zhuohui Gan ◽  
David L. Roerig ◽  
Anne V. Clough ◽  
Said H. Audi
Keyword(s):  
Lung Tissue ◽  
Complex I ◽  
Complex Iii ◽  
Oxygen Species ◽  
Mitochondrial Complex ◽  
Complex Iv ◽  
Arterial Inflow ◽  
Tissue Homogenates ◽  
Species Production ◽  
Complex I Activity

Rat exposure to 60% O2 (hyper-60) or 85% O2 (hyper-85) for 7 days confers susceptibility or tolerance, respectively, of the otherwise lethal effects of exposure to 100% O2. The objective of this study was to determine whether activities of the antioxidant cytosolic enzyme NAD(P)H:quinone oxidoreductase 1 (NQO1) and mitochondrial complex III are differentially altered in hyper-60 and hyper-85 lungs. Duroquinone (DQ), an NQO1 substrate, or its hydroquinone (DQH2), a complex III substrate, was infused into the arterial inflow of isolated, perfused lungs, and the venous efflux rates of DQH2 and DQ were measured. Based on inhibitor effects and kinetic modeling, capacities of NQO1-mediated DQ reduction ( Vmax1) and complex III-mediated DQH2 oxidation ( Vmax2) increased by ∼140 and ∼180% in hyper-85 lungs, respectively, compared with rates in lungs of rats exposed to room air (normoxic). In hyper-60 lungs, Vmax1 increased by ∼80%, with no effect on Vmax2. Additional studies revealed that mitochondrial complex I activity in hyper-60 and hyper-85 lung tissue homogenates was ∼50% lower than in normoxic lung homogenates, whereas mitochondrial complex IV activity was ∼90% higher in only hyper-85 lung tissue homogenates. Thus NQO1 activity increased in both hyper-60 and hyper-85 lungs, whereas complex III activity increased in hyper-85 lungs only. This increase, along with the increase in complex IV activity, may counter the effects the depression in complex I activity might have on tissue mitochondrial function and/or reactive oxygen species production and may be important to the tolerance of 100% O2 observed in hyper-85 rats.

scholarly journals Atomic structures of respiratory complex III2, complex IV and supercomplex III2-IV from vascular plants

2020 ◽  
Author(s):  
María Maldonado ◽  
Fei Guo ◽  
James A. Letts
Keyword(s):  
Vascular Plants ◽  
Proton Translocation ◽  
Complex Iii ◽  
Conformational Heterogeneity ◽  
Mitochondrial Matrix ◽  
Mitochondrial Complex ◽  
Complex Iv ◽  
Atomic Structures ◽  
Iron Sulfur ◽  
Heterogeneity Analysis

Mitochondrial complex III (CIII2) and complex IV (CIV), which can associate into a higher-order supercomplex (SC III2+IV), play key roles in respiration. However, structures of these plant complexes remain unknown. We present atomic models of CIII2, CIV and SC III2+IV from Vigna radiata determined by single-particle cryoEM. The structures reveal plant-specific differences in the MPP domain of CIII2 and define the subunit composition of CIV. Conformational heterogeneity analysis of CIII2 revealed long-range, coordinated movements across the complex, as well as the motion of CIII2’s iron-sulfur head domain. The CIV structure suggests that, in plants, proton translocation does not occur via the H-channel. The supercomplex interface differs significantly from that in yeast and bacteria in its interacting subunits, angle of approach and limited interactions in the mitochondrial matrix. These structures challenge long-standing assumptions about the plant complexes, generate new mechanistic hypotheses and allow for the generation of more selective agricultural inhibitors.

scholarly journals COA6 is a mitochondrial complex IV assembly factor critical for biogenesis of mtDNA-encoded COX2

2015 ◽  
Vol 24 (19) ◽  
pp. 5404-5415 ◽  
Author(s):  
David A. Stroud ◽  
Megan J. Maher ◽  
Caroline Lindau ◽  
F.-Nora Vögtle ◽  
Ann E. Frazier ◽  
...  
Keyword(s):  
Mitochondrial Complex ◽  
Complex Iv ◽  
Assembly Factor

Mutations in TTC19 cause mitochondrial complex III deficiency and neurological impairment in humans and flies

2011 ◽  
Vol 43 (3) ◽  
pp. 259-263 ◽  
Author(s):  
Daniele Ghezzi ◽  
Paola Arzuffi ◽  
Mauro Zordan ◽  
Caterina Da Re ◽  
Costanza Lamperti ◽  
...  
Keyword(s):  
Neurological Impairment ◽  
Complex Iii ◽  
Mitochondrial Complex

scholarly journals Early-adolescent antibiotic exposure results in mitochondrial and behavioral deficits in adult male mice

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Anouk C. Tengeler ◽  
Tim L. Emmerzaal ◽  
Bram Geenen ◽  
Vivienne Verweij ◽  
Miranda van Bodegom ◽  
...  
Keyword(s):  
Cerebral Cortex ◽  
Mitochondrial Function ◽  
Adolescent Male ◽  
Mitochondrial Complex ◽  
Mitochondrial Translation ◽  
Behavioral Screening ◽  
Behavioral Deficits ◽  
Complex Iv ◽  
Marble Burying ◽  
Behavior And Cognition

AbstractExposure to antibiotic treatment has been associated with increased vulnerability to various psychiatric disorders. However, a research gap exists in understanding how adolescent antibiotic therapy affects behavior and cognition. Many antibiotics that target bacterial translation may also affect mitochondrial translation resulting in impaired mitochondrial function. The brain is one of the most metabolically active organs, and hence is the most vulnerable to impaired mitochondrial function. We hypothesized that exposure to antibiotics during early adolescence would directly affect brain mitochondrial function, and result in altered behavior and cognition. We administered amoxicillin, chloramphenicol, or gentamicin in the drinking water to young adolescent male wild-type mice. Next, we assayed mitochondrial oxidative phosphorylation complex activities in the cerebral cortex, performed behavioral screening and targeted mass spectrometry-based acylcarnitine profiling in the cerebral cortex. We found that mice exposed to chloramphenicol showed increased repetitive and compulsive-like behavior in the marble burying test, an accurate and sensitive assay of anxiety, concomitant with decreased mitochondrial complex IV activity. Our results suggest that only adolescent chloramphenicol exposure leads to impaired brain mitochondrial complex IV function, and could therefore be a candidate driver event for increased anxiety-like and repetitive, compulsive-like behaviors.

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