Expression of Saccharomyces cerevisiae Sdh3p and Sdh4p Paralogs Results in Catalytically Active Succinate Dehydrogenase Isoenzymes
| Autor: | Kayode S. Oyedotun, Stacey N. Reinke, Brian D. Sykes, Samuel S.W. Szeto, Bernard D. Lemire |
|---|---|
| Rok vydání: | 2012 |
| Předmět: |
Saccharomyces cerevisiae Proteins
Ubiquinone Protein subunit Molecular Sequence Data Saccharomyces cerevisiae Flavin group Bioenergetics Mitochondrial Membrane Transport Proteins Biochemistry Antiporters Catalysis Gene Expression Regulation Enzymologic Cofactor Enzyme activator Gene Expression Regulation Fungal Mitochondrial Precursor Protein Import Complex Proteins Metabolomics Amino Acid Sequence Molecular Biology biology Electron Transport Complex II Succinate dehydrogenase Cell Biology biology.organism_classification Enzyme structure Enzyme Activation Isoenzymes Succinate Dehydrogenase Protein Subunits Phenotype Mitochondrial Membranes biology.protein |
| Zdroj: | Journal of Biological Chemistry. 287:22509-22520 |
| ISSN: | 0021-9258 |
| DOI: | 10.1074/jbc.m112.344275 |
| Popis: | Succinate dehydrogenase (SDH), also known as complex II, is required for respiratory growth; it couples the oxidation of succinate to the reduction of ubiquinone. The enzyme is composed of two domains. A membrane-extrinsic catalytic domain composed of the Sdh1p and Sdh2p subunits harbors the flavin and iron-sulfur cluster cofactors. A membrane-intrinsic domain composed of the Sdh3p and Sdh4p subunits interacts with ubiquinone and may coordinate a b-type heme. In many organisms, including Saccharomyces cerevisiae, possible alternative SDH subunits have been identified in the genome. S. cerevisiae contains one paralog of the Sdh3p subunit, Shh3p (YMR118c), and two paralogs of the Sdh4p subunit, Shh4p (YLR164w) and Tim18p (YOR297c). We cloned and expressed these alternative subunits. Shh3p and Shh4p were able to complement Δsdh3 and Δsdh4 deletion mutants, respectively, and support respiratory growth. Tim18p was unable to do so. Microarray and proteomics data indicate that the paralogs are expressed under respiratory and other more restrictive growth conditions. Strains expressing hybrid SDH enzymes have distinct metabolic profiles that we distinguished by 1H NMR analysis of metabolites. Surprisingly, the Sdh3p subunit can form SDH isoenzymes with Sdh4p or with Shh4p as well as be a subunit of the TIM22 mitochondrial protein import complex. Background: Succinate dehydrogenase is a tetrameric, mitochondrial membrane protein needed for respiratory energy generation. Results: Yeast succinate dehydrogenase containing Sdh3p and Sdh4p paralogs is catalytically active. Conclusion: Expression of paralogous subunits results in enzymes with novel kinetic properties. Significance: At least four functional succinate dehydrogenase isoenzymes containing zero, one, or two paralogs can be expressed in yeast mitochondria. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|