Carbon source-dependent regulation of a second gene encoding glutaredoxin from the fission yeast Schizosaccharomyces pombe.
Glutaredoxin (Grx), also known as thioltransferase (TTase), is an enzyme that catalyzes the reduction of a variety of disulfide compounds, including protein disulfides, in the presence of reduced glutathione. A second gene encoding Grx (Grx2) was cloned from the chromosomal DNA of the fission yeast Schizosaccharomyces pombe. The determined DNA sequence contains 1645 bp which is able to encode a polypeptide of 110 amino acids with a molecular mass of 12.2 kDa. The genomic DNA consists of 4 exons and 3 introns. The isolated gene was found to produce functional glutaredoxin that could accelerate the growth of the fission yeast, and is highly expressed at the mid- and late exponential phases. Aluminum, cadmium and hydrogen peroxide marginally enhanced the synthesis of beta-galactosidase from the Grx2-lacZ fusion gene. Shifts to lower concentrations (0.2, 0.4 or 0.8%) of D-glucose significantly enhanced the synthesis of beta-galactosidase from the Grx2-lacZ fusion gene. And shifts to sucrose (0.2, 0.4, 0.8 or 1.6%) as a sole carbon source markedly enhanced the synthesis of beta-galactosidase from the Grx2-lacZ fusion gene, the degree of which was inversely dependent on concentration. However, nonfermentable carbon sources reduced the expression of the Grx2 gene due to their growth arrest. The transcription factor Pap1 is not involved in the basal expression and induction of the Grx2 gene. The Grx2 protein was subcellularly localized in the nucleus of the yeast cells. Our results indicate that the Grx2 protein, located in the nucleus, is linked with the yeast growth, and that the gene is regulated by carbon sources.
Kim
Hong-Gyum
HG
Division of Life Sciences, College of Natural Sciences, Kangwon National University, Chuncheon 200-701, Korea.
Kim
Ji-Hyun
JH
Kim
Byung-Chul
BC
Park
Eun-Hee
EH
Lim
Chang-Jin
CJ
D000595:Amino Acid Sequence; D001483:Base Sequence; D050976:Basic-Leucine Zipper Transcription Factors; D002244:Carbon / Q000378:metabolism*; D002467:Cell Nucleus / Q000737:chemistry; D004268:DNA-Binding Proteins / Q000378:metabolism; D005656:Fungal Proteins / Q000378:metabolism; D015966:Gene Expression Regulation, Fungal; D054477:Glutaredoxins; D008969:Molecular Sequence Data; D010088:Oxidoreductases / Q000032:analysis / Q000235:genetics* / Q000378:metabolism; D000073718:Pancreatitis-Associated Proteins; D012568:Schizosaccharomyces / Q000201:enzymology* / Q000235:genetics; D029702:Schizosaccharomyces pombe Proteins / Q000032:analysis / Q000235:genetics* / Q000378:metabolism
D050976:Basic-Leucine Zipper Transcription Factors; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; D054477:Glutaredoxins; D000073718:Pancreatitis-Associated Proteins; C105096:Pap1 protein, S pombe; C000612141:REG3A protein, human; D029702:Schizosaccharomyces pombe Proteins; D002244:Carbon; D010088:Oxidoreductases