RESUMEN
In the current work, regulation of the pap1(+) gene was investigated by the use of the pap1(+)-lacZ fusion gene and semi-quantitative reverse transcriptase-PCR. The synthesis of beta-galactosidase from the pap1(+)-lacZ fusion gene was significantly enhanced by nitric oxide (NO)-generating sodium nitroprusside (SNP) and nitrogen starvation. However, the induction by SNP and nitrogen starvation was observed to be much less in the Pap1p-negative cells harboring the fusion gene. Exogenous NO was more effectively scavenged in the Pap1p-positive cells than in the Pap1p-negative cells. Oxidative stress such as superoxide anion, hydrogen peroxide and cadmium could not give rise to an effect on the synthesis of beta-galactosidase from the fusion gene. The pap1(+) mRNA level was elevated in the wild-type cells by SNP and nitrogen starvation. Catalase activity, a major enzyme positively regulated by Pap1p, was significantly increased only in the Pap1p-positive cells by SNP. In brief, it is demonstrated that transcription of the Schizosaccharomyces pombe pap1(+) gene is positively regulated by nitrosative and nutritional stress in a Pap1p-dependent manner.
