Evidence for the Presence of a Second Electron Donor for the Cytoplasmic Thioredoxins in the Yeast Saccharomyces cerevisiae

Ahmet KOÇ; Hüseyin Ç. KARAKAYA; Ercan S. ÜNLÜ

Makale detayları

Evidence for the Presence of a Second Electron Donor for the Cytoplasmic Thioredoxins in the Yeast Saccharomyces cerevisiae

Yazarlar:

Ahmet KOÇ | Hüseyin Ç. KARAKAYA | Ercan S. ÜNLÜ

Yayıncı:

TUBITAK

Dergi:

Turkish Journal of Biology 2006 Vol.30 Issue 3, pp.133-138

Belge Tipi:

Makale

Yayın Tarihi:

2/2006

Belge Dili:

Türkçe

Document ID (Org No.):

2000813356

Sıklık:

İki Aylık

eISSN:

1303-6092

pISSN:

1300-0152

Anahtar kelimeler:

Özet:

 

In yeast, the cytoplasmic thioredoxin system is composed of NADPH, thioredoxin reductase-1 (TRR1) and 2 thioredoxin genes (TRX1, TRX2). In this study, using yeast knockout mutants for TRR1, TRX1 and TRX2 genes, the role of the thioredoxin system in methionine sulfoxide reduction was investigated. Cells lacking both TRX1 and TRX2 genes simultaneously were not able to reduce methionine sulfoxides to methionine; however, mutants missing the TRR1 gene were able to reduce methionine sulfoxides to methionine, which showed that electrons could be transferred from NADPH to thioredoxins in the absence of TRR1. Similar results were observed for 3-phosphoadenosine 5-phosphosulfate reduction in the inorganic sulfate assimilation pathway. Results from both assays suggested that yeast cells have additional cytoplasmic thioredoxin reductase activity that could compensate for methionine sulfoxide reduction and sulfate assimilation in the absence of TRR1. This report also constitutes the first evidence that thioredoxins are the in vivo electron donors for methionine sulfoxide reductases in yeast.

 

In yeast, the cytoplasmic thioredoxin system is composed of NADPH, thioredoxin reductase-1 (TRR1) and 2 thioredoxin genes (TRX1, TRX2). In this study, using yeast knockout mutants for TRR1, TRX1 and TRX2 genes, the role of the thioredoxin system in methionine sulfoxide reduction was investigated. Cells lacking both TRX1 and TRX2 genes simultaneously were not able to reduce methionine sulfoxides to methionine; however, mutants missing the TRR1 gene were able to reduce methionine sulfoxides to methionine, which showed that electrons could be transferred from NADPH to thioredoxins in the absence of TRR1. Similar results were observed for 3-phosphoadenosine 5-phosphosulfate reduction in the inorganic sulfate assimilation pathway. Results from both assays suggested that yeast cells have additional cytoplasmic thioredoxin reductase activity that could compensate for methionine sulfoxide reduction and sulfate assimilation in the absence of TRR1. This report also constitutes the first evidence that thioredoxins are the in vivo electron donors for methionine sulfoxide reductases in yeast.

Makale detayları

Evidence for the Presence of a Second Electron Donor for the Cytoplasmic Thioredoxins in the Yeast Saccharomyces cerevisiae

Yazarlar:

Ahmet KOÇ | Hüseyin Ç. KARAKAYA | Ercan S. ÜNLÜ

Yayıncı:

TUBITAK

Dergi:

Turkish Journal of Biology 2006 Vol.30 Issue 3, pp.133-138

Belge Tipi:

Makale

Yayın Tarihi:

2/2006

Belge Dili:

Türkçe

Document ID (Org No.):

2000813356

Sıklık:

İki Aylık

eISSN:

1303-6092

pISSN:

1300-0152

Thioredoxin reductase

thioredoxin

methionine

methionine sulfoxide

yeast

Saccharomyces cerevisiae

Sayı

Makale detayları

Evidence for the Presence of a Second Electron Donor for the Cytoplasmic Thioredoxins in the Yeast Saccharomyces cerevisiae

Yazarlar: Ahmet KOÇ | Hüseyin Ç. KARAKAYA | Ercan S. ÜNLÜ

Yayıncı: TUBITAK

Dergi: Turkish Journal of Biology 2006 Vol.30 Issue 3, pp.133-138

Belge Tipi: Makale

Yayın Tarihi: 2/2006

Belge Dili: Türkçe

Document ID (Org No.): 2000813356

Sıklık: İki Aylık

eISSN: 1303-6092

pISSN: 1300-0152

Thioredoxin reductase

thioredoxin

methionine

methionine sulfoxide

yeast

Saccharomyces cerevisiae

Sayı

Yazarlar:

Ahmet KOÇ | Hüseyin Ç. KARAKAYA | Ercan S. ÜNLÜ

Yayıncı:

TUBITAK

Dergi:

Turkish Journal of Biology 2006 Vol.30 Issue 3, pp.133-138

Belge Tipi:

Makale

Yayın Tarihi:

2/2006

Belge Dili:

Türkçe

Document ID (Org No.):

2000813356

Sıklık:

İki Aylık

eISSN:

1303-6092

pISSN:

1300-0152