Journal of Microbiology

Research Support, Non-U.S. Gov't

Transcriptional Regulation of the Gene Encoding g-Glutamylcysteine Synthetase from the Fission Yeast Schizosaccharomyces pombe: Su-Jung Kim , Hong-Gyum Kim , Byung-Chul Kim , Kyunghoon Kim , Eun-Hee Park , Chang-Jin Lim; J. Microbiol. 2004;42(3):233-238.; DOI: https://doi.org/2083 [pii]

Abstract: Transcriptional regulation of the Schizosaccharomyces pombe [gamma]-glutamylcysteine synthetase (GCS) gene was examined using the two GCS-lacZ fusion plasmids pUGCS101 and pUGCS102, which harbor 607 bp and 447 bp upstream regions, respectively. The negatively-acting sequence was located in the -607 ~ -447 bp upstream region of the GCS gene. The upstream sequence responsible for induction by menadione (MD) and L-buthionine-(S, R)-sulfoximine (BSO) resides in the -607 ~ -447 bp region, whereas the sequence which codes for nitric oxide induction is located within the -447 bp region, measured from the translational initiation point. Carbon source-dependent regulation of the GCS gene appeared to be dependent on the nucleotide sequence within -447 bp region. The transcription factor Pap1 is involved in the induction of the GCS gene by MD and BSO, but not by nitric oxide. Induction of the GCS gene occurring due to low glucose concentration does not depend on the presence of Pap1. These data imply that induction by MD and BSO may be mediated by the Pap1 binding site, probably located in the -607 ~ -447 region, and also that the nitric oxide-mediated regulation of the S. pombe GCS gene may share a similar mechanism with its carbon-dependent induction.

Glutathione Content and the Activities of GlutathioneSynthesizing Enzymes in Fission Yeast are Modulated by Oxidative Stress: Yuk-Young Lee , Su-Jung Kim , Eun-Hee Park , Chang-Jin Lim; J. Microbiol. 2003;41(3):248-251.

Abstract: Glutathione (GSH) is an important factor in determining tolerance against oxidative stress in living organisms. It is synthesized in two sequential reactions catalyzed by [gamma]-glutamylcysteine synthetase (GCS) and glutathione synthetase (GS) in the presence of ATP. In this work, the effects of three different oxidative stresses were examined on GSH content and GSH-related enzyme activities in the fission yeast Schizosaccharomyces pombe. GSH content in S. pombe was significantly enhanced by treatment with hydrogen peroxide, [beta]-naphthoflavone (BNF) and tert-butylhydroquinone (BHQ). Simultaneously, they greatly induced GCS and GS activity. However, they did not have any effects on glutathione reductase activity. These results suggest that GCS and GS activities in S. pombe are upregulated by oxidative stress.

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