• Journal of Microbiology and Biotechnology
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• v.16 no.9
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• pp.1459-1463
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• 2006

This study explored yeast diauxic promoters using a green fluorescent protein (GFP) reporter to screen growth phase-controlled promoters applicable for foreign protein production. Twenty-five diauxic promoters were inserted into a yeast 2-micron vector in front of the reporter GFP gene. The expressed GFP signal intensity measurements showed that 23 out of the 25 promoters produced a significant fluorescent signal when the cells were in the diauxic growth phase. Among the two strongest promoters pYDL204W and pYLR258W, the former remained constantly active after its activation at the diauxic shift, whereas the latter was only transiently activated right after the deprivation of the medium glucose.

• Proceedings of the Microbiological Society of Korea Conference
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• 2005.05a
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• pp.105-109
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• 2005

Heat Shock Transcription Factor (HSF), and the promoter heat Shock Element (HSE), are among the most highly conserved transcriptional regulatory elements in nature. HSF mediates the transcriptional response of eukaryotic cells to heat, infection and inflammation, pharmacological agents, and other stresses. While HSF is essential for cell viability in yeast, oogenesis and early development in Drosophila, extended life-span in C. elegans, and extra-embryonic development and stress resistance in mammals, little is known about its full range of biological target genes. We used whole genome analyses to identify virtually all of the direct transcriptional targets of yeast HSF, representing nearly three percent of the genomic loci. The majority of the identified loci are heat-inducibly bound by yeast HSF, and the target genes encode proteins that have a broad range of biological functions including protein folding and degradation, energy generation, protein secretion, maintenance of cell integrity, small molecule transport, cell signaling, and transcription. Approximately 30% of the HSF direct target genes are also induced by the diauxic shift, in which glucose levels begin to be depleted. We demonstrate that phosphorylation of HSF by Snf1 kinase is responsible for expression of a subset of HSF targets upon glucose starvation.

• Proceedings of the Zoological Society Korea Conference
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• 1998.10b
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• pp.113-113
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• 1998

In Saccharomyces cerevisiae UV irradiation and a variety of chemical DNA -damaging agents induce the transcription of specific genes, including several involved in DNA repair. One of the best characterized of DNA -damage inducible genes is PHRI, which encodes the apoenzyme for DNA photolyase. Basal-level and damage-induced expression of PHRI require an upstream activation sequence, UASPHRI. Here we report the identification of the UlvIE6 gene of S. cerevisiae as a regulator of UASPHRl activity. Surprisingly, the effect of deletion of UME6 is growth phase dependent. In wild-type cells PHRI is induced in late exponential phase, concomitant with the initiation of glycogen accumulation that precedes the diauxic shift. Deletion of UNIE6 abolishes this induction, decreases the steady-state concentration of photolyase molecules and PHRI mRNA, and increases the UV sensitivity of a rad2 mutant. The results suggest that UM E6 contributes to the regulated expression of a subset of damage-responsive genes in yeast. Furthermore, the upstream repression sequence, URSPHRI, is required for repression and damage-induced expression of PHRl. Here we show identification of YER169W and YDR096W as putative regulators acting through $URS_{PHRI}$. These open reading frames were designated as RPHI (YERl69W) and RPH2 (YDR096W) indicating regulator of PHRI. Simultaneous disruption of both genes showed a synergistic effect, producing a four-fold increase in basal level expression and a similar decrease m the induction ratio following treatment of methyl methanesulfonate(MMS). Mutation of the sequence ($AG_4$) bound by Rphlp rendered the promoter of PHRI insensitive to changes in RPHI or RPH2 status. The data suggest that RPHI and RPH2 act as damage-responsive negative regulators of PHRI. Surprisingly, the sequence bound by Rphlp in vitro is found to be $AG_4$ which is identical to the consensus binding site for the regulators Msn2p and Msn4p involved in stress-induced expression. Deletion of MSN2 and MSN4 has little effect on the induction$.$ ratio following DNA damage. However, all deletions led to a significant decrease in basal-level and induced expression of PHRI. These results imply that MSN2 and MSN4 are positive regulators of P HRI but are not required for DNA damage repression. [Supported by grant from NIH]om NIH]