Uncoupling protein 1 inhibition by purine nucleotides is under the control of the endogenous ubiquinone redox state
| Autor: | Andrzej Woyda-Ploszczyca, Francis Sluse, Wieslawa Jarmuszkiewicz, Aleksandra Swida-Barteczka |
|---|---|
| Rok vydání: | 2009 |
| Předmět: |
Male
Purine GTP' Ubiquinone Saccharomyces cerevisiae Fatty Acids Nonesterified Biology Mitochondrion Biochemistry Redox Ion Channels Mitochondrial Proteins chemistry.chemical_compound Brown adipose tissue medicine Animals Nucleotide Phosphorylation Purine Nucleotides Molecular Biology Uncoupling Protein 1 chemistry.chemical_classification Cell Biology biology.organism_classification Thermogenin Mitochondria Rats Adipocytes Brown medicine.anatomical_structure chemistry Oxidation-Reduction Protein Binding |
| Zdroj: | Biochemical Journal. 424:297-306 |
| ISSN: | 1470-8728 0264-6021 |
| DOI: | 10.1042/bj20091158 |
| Popis: | We studied non-esterified fatty acid-induced uncoupling of heterologously expressed rat UCP1 (uncoupling protein 1) in yeast mitochondria, as well as UCP1 in rat BAT (brown adipose tissue) mitochondria. The proton-conductance curves and the relationship between the ubiquinone reduction level and membrane potential were determined in non-phosphorylating BAT and yeast mitochondria. The ADP/O method was applied to determine the ADP phosphorylation rate and the relationship between the ubiquinone reduction level and respiration rate in yeast mitochondria. Our studies of the membranous ubiquinone reduction level in mitochondria demonstrate that activation of UCP1 leads to a purine nucleotide-sensitive decrease in the ubiquinone redox state. Results obtained for non-phosphorylating and phosphorylating mitochondria, as the endogenous ubiquinone redox state was gradually varied by a lowering rate of the ubiquinone-reducing or ubiquinol-oxidizing pathways, indicate that the endogenous ubiquinone redox state has no effect on non-esterified fatty acid-induced UCP1 activity in the absence of GTP, and can only regulate this activity through sensitivity to inhibition by the purine nucleotide. At a given oleic acid concentration, inhibition by GTP diminishes when ubiquinone is reduced sufficiently. The ubiquinone redox state-dependent alleviation of UCP1 inhibition by the purine nucleotide was observed at a high ubiquinone reduction level, when it exceeded 85–88%. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|