Cytosolic thioredoxin peroxidase I is essential for the antioxidant defense of yeast with dysfunctional mitochondria.
The specific role of cytosolic thioredoxin peroxidase I (cTPx I), encoded by TSA1 (thiol-specific antioxidant), was investigated in the oxidative stress response of Saccharomyces cerevisiae. In most cases, deletion of TSA1 has showed only a slight effect on hydrogen peroxide sensitivity. However, when the functional state of the mitochondria was compromised, the necessity of TSA1 in cell protection against this oxidant was much more evident. All the procedures used to disrupt the mitochondrial respiratory chain promoted increases in the generation of H(2)O(2) in cells, which could be related to their elevated sensitivity to oxidative stress. In fact, TSA1 is highly expressed when cells with respiratory deficiency are exposed to H(2)O(2). In conclusion, our results indicate that cTPx I is a key component of the antioxidant defense in respiratory-deficient cells.
Demasi
A P
AP
Departamento de Bioquímica, IB, UNICAMP, SP, Brazil.
Pereira
G A
GA
Netto
L E
LE
D000975:Antioxidants / Q000378:metabolism; D002455:Cell Division / Q000187:drug effects; D019069:Cell Respiration / Q000187:drug effects; D005470:Fluorometry; D015966:Gene Expression Regulation, Fungal / Q000187:drug effects; D006861:Hydrogen Peroxide / Q000378:metabolism / Q000494:pharmacology; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology*; D009363:Neoplasm Proteins; D018384:Oxidative Stress / Q000187:drug effects; D010544:Peroxidases / Q000235:genetics / Q000378:metabolism*; D054464:Peroxiredoxins; D017382:Reactive Oxygen Species / Q000494:pharmacology; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic / Q000187:drug effects
D000975:Antioxidants; D009363:Neoplasm Proteins; D017382:Reactive Oxygen Species; D006861:Hydrogen Peroxide; D010544:Peroxidases; D054464:Peroxiredoxins