Mitochondrial and Cytoplasmic Thioredoxin Reductase Variants Encoded by a Single Drosophila Gene Are Both Essential for Viability
| Autor: | Ulrich Schäfer, Herbert Jäckle, Julia K. Ulschmid, Katja Becker, Sebastian Grönke, Mitsuko Hirosawa-Takamori, John P. Phillips, Fanis Missirlis |
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| Rok vydání: | 2002 |
| Předmět: |
Gene isoform
Cytoplasm 7-Dehydrocholesterol reductase Thioredoxin-Disulfide Reductase Thioredoxin reductase Longevity Glutathione reductase Mitochondrion Biology Biochemistry chemistry.chemical_compound Glutaredoxin Animals Molecular Biology DNA Primers Base Sequence Cell Biology Glutathione Recombinant Proteins Mitochondria Kinetics Oxidative Stress chemistry Mutation Drosophila Thioredoxin |
| Zdroj: | Journal of Biological Chemistry |
| ISSN: | 0021-9258 |
| DOI: | 10.1074/jbc.m111692200 |
| Popis: | Defense against oxidative stress in mammals includes the regeneration of the major thiol reductants glutathione and thioredoxin by glutathione reductase and thioredoxin reductase (TrxR), respectively. In contrast, Drosophila, and possibly insects in general, lacks glutathione reductase and must rely solely on the TrxR system. The mammalian TrxRs described so far are selenoproteins that utilize NADPH to reduce protein as well as nonprotein substrates in mitochondria and cytoplasm of cells. We show that a single Drosophila gene, Trxr-1, encodes non-selenocysteine-containing cytoplasmic and mitochondrial TrxR isoforms that differ with respect to their N termini. We generated transcript-specific mutants and used in vivo approaches to explore the biological functions of the two enzyme variants by introducing the corresponding transgenes into different Trxr-1 mutants. The results show that, although the two TrxR isoforms have similar biochemical properties, their biological functions are not interchangeable. |
| Databáze: | OpenAIRE |
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