Lack of Cytochrome c in Mouse Fibroblasts Disrupts Assembly/Stability of Respiratory Complexes I and IV

Department of Neurology and Department of Cell Biology and Anatomy, University of Miami Miller School of Medicine, Miami, Florida 33136, USA.
Journal of Biological Chemistry (Impact Factor: 4.6). 02/2009; 284(7):4383-91. DOI: 10.1074/jbc.M805972200
Source: PubMed

ABSTRACT Cytochrome c (cyt c) is a heme-containing protein that participates in electron transport in the respiratory chain and as a signaling molecule in the apoptotic cascade. Here we addressed the effect of removing mammalian cyt c on the integrity of the respiratory complexes in mammalian cells. Mitochondria from cyt c knockout mouse cells lacked fully assembled complexes I and IV and had reduced levels of complex III. A redox-deficient mutant of cyt c was unable to rescue the levels of complexes I and IV. We found that cyt c is associated with both complex IV and respiratory supercomplexes, providing a potential mechanism for the requirement for cyt c in the assembly/stability of complex IV.

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