Cytochromecoxidase is regulated by modulations in protein expression and mitochondrial membrane phospholipid composition in estivating African lungfish
| Autor: | Jason S. Bystriansky, N T Frick, James S. Ballantyne, Yuen K. Ip, Shit F. Chew |
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| Rok vydání: | 2010 |
| Předmět: |
Cardiolipins
Physiology Protein subunit macromolecular substances Mitochondrion Gene Expression Regulation Enzymologic Electron Transport Complex IV chemistry.chemical_compound Protopterus dolloi Physiology (medical) Cardiolipin Animals Cytochrome c oxidase RNA Messenger Inner mitochondrial membrane Phosphatidylethanolamine Protopterus biology Reverse Transcriptase Polymerase Chain Reaction Fishes biology.organism_classification Estivation Mitochondria Liver Biochemistry chemistry Mitochondrial Membranes biology.protein Energy Metabolism |
| Zdroj: | American Journal of Physiology-Regulatory, Integrative and Comparative Physiology. 298:R608-R616 |
| ISSN: | 1522-1490 0363-6119 |
| Popis: | We examined some of the potential mechanisms lungfish (Protopterus dolloi) use to regulate cytochrome c oxidase (CCO), during metabolic depression. CCO activity was reduced by 67% in isolated liver mitochondria of estivating fish. This was likely accomplished, in part, by the 46% reduction in CCO subunit I protein expression in the liver. No change in the mRNA expression levels of CCO subunits I, II, III, and IV were found in the liver, suggesting CCO is under translational regulation; however, in the kidney, messenger limitation may be a factor as the expression of subunits I and II were depressed ( approximately 10-fold) during estivation, suggesting tissue-specific mechanisms of regulation. CCO is influenced by mitochondrial membrane phospholipids, particularly cardiolipin (CL). In P. dolloi, the phospholipid composition of the liver mitochondrial membrane changed during estivation, with a approximately 2.3-fold reduction in the amount of CL. Significant positive correlations were found between CCO activity and the amount of CL and phosphatidylethanolamine within the mitochondrial membrane. It appears CCO activity is regulated through multiple mechanisms in P. dolloi, and individual subunits of CCO are regulated independently, and in a tissue-specific manner. It is proposed that altering the amount of CL within the mitochondrial membrane may be a means of regulating CCO activity during metabolical depression in the African lungfish, P. dolloi. |
| Databáze: | OpenAIRE |
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