Abstract
A number of distinct cuproproteins of the mitochondrial inner membrane are required for the assembly of cytochrome oxidase (COX), thought to function in a “bucket brigade” fashion to provide copper to the CuA and CuB sites. In yeast, the loss of two these proteins, Sco1p and Cox11p, leads to respiratory deficiency and a specific inability to survive exposure to hydrogen peroxide (H2O2). Using a quantitative assay, we have identified subtle differences in the peroxide-sensitive phenotypes between sco1 and cox11 mutant strains. Interestingly, the peroxide sensitivity of the sco1 null strain can be suppressed by overexpressing either SCO2 or COX11, although overexpression of neither SCO1 nor SCO2 can rescue the cox11 null strain. We also find that overexpression of either CTT1, encoding the cytosolic catalase T, or CTA1, encoding the mitochondrial matrix catalase, suppresses the peroxide sensitivity in both the sco1 and the cox11 null mutants. Direct measurement of peroxide metabolism shows that sco1 and cox11 null strains fail to degrade a significant amount of exogenously provided H2O2. Taken together, our data demonstrate that although Cox11p and Sco1p play distinct roles in COX assembly, they seem to play overlapping or related roles in peroxide metabolism that require further investigation.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.