This Article Full Text Full Text (PDF) Other Versions of this Article: AEM.01963-06v1 73/2/572    most recent Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Maeta, K. Articles by Inoue, Y. Search for Related Content PubMed PubMed Citation Articles by Maeta, K. Articles by Inoue, Y. Agricola Articles by Maeta, K. Articles by Inoue, Y.

Green Tea Polyphenols Function as Prooxidants To Activate Oxidative-Stress-Responsive Transcription Factors in Yeasts

Kazuhiro Maeta, Wataru Nomura, Yoshifumi Takatsume, Shingo Izawa, and Yoshiharu Inoue^*

Laboratory of Molecular Microbiology, Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011, Japan

Received 17 August 2006/ Accepted 12 November 2006

Epigallocatechin gallate (EGCG) is the most abundant polyphenolic flavonoid in green tea. Catechin and its derivatives, including EGCG, are widely believed to function as antioxidants. Here we demonstrate that both EGCG and green tea extract (GTE) cause oxidative stress-related responses in the budding yeast Saccharomyces cerevisiae and the fission yeast Schizosaccharomyces pombe under weak alkaline conditions in terms of the activation of oxidative-stress-responsive transcription factors. GTE as well as EGCG induced the nuclear localization of Yap1 in S. cerevisiae, which was repressed by the addition of catalase but not by the addition of superoxide dismutase. The same phenomena were observed for the nucleocytoplasmic localization of Msn2 in S. cerevisiae and Pap1, a Yap1 homologue, in S. pombe. The formation of intramolecular disulfide bonds has been proposed to be crucial for the H₂O₂-induced nuclear localization of Yap1, and we verified the importance of cysteine residues of Yap1 in response to EGCG and GTE. Additionally, we show that EGCG and GTE produce H₂O₂ in a weak alkaline medium. Finally, we conclude that tea polyphenols are able to act as prooxidants to cause a response to oxidative stress in yeasts under certain conditions.

Published ahead of print on 22 November 2006.

Present address: Chemical Genetics Laboratory, RIKEN, Wako, Saitama 351-0198, Japan.

This article has been cited by other articles:

• Inoue, Y., Nomura, W., Takeuchi, Y., Ohdate, T., Tamasu, S., Kitaoka, A., Kiyokawa, Y., Masutani, H., Murata, K., Wakai, Y., Izawa, S., Yodoi, J. (2007). Efficient Extraction of Thioreodoxin from Saccharomyces cerevisiae by Ethanol. Appl. Environ. Microbiol. 73: 1672-1675 [Abstract] [Full Text]