4. International Congress on Applied Biological Sciences (ICABS), Eskişehir, Turkey, 3 - 05 May 2018, vol.1, no.1, pp.1
GIS1 is a C2H2 zing finger DNA binding transcription factor that acts as a both transcriptional activator and repressor for different target genes in Saccharomyces cerevisiae. Gis1 regulates gene expressions in response to diauxic shift which is changing metabolism from fermentation of glucose to oxidation of ethanol whenever glucose consumed. Gis1 acts as a transcriptional activator of genes involved in stationary phase. Gis1 specifically binds T(A/T)AGGGAT sequence, PDS (Post Diauxic Shift) element, that is present in the promoters of target genes. GIS1 is a regulatory target of the Protein Kinase A (PKA), Sch9 kinase and TOR pathway. NTH1 gene encodes neutral trehalase enzyme that is responsible from the degradation of stres accumulated trehalose in S. cerevisiae yeast cells. The transcription of NTH1 gene is activated in different stress conditions through a Stress Response Element (STRE) and PDS element that is present in the promotor of NTH1 gene. NTH1 gene expression is regulated by PKA and TOR pathways, also. That’s why in our research we investigated the effects of Gis1 transcription factor on NTH1 gene expression. For that purpose, Δgis1 mutant yeast and its isogenic wild-type yeast strain, BY4741, were used to analyze NTH1 gene induction in logarithmic, post diauxic and stationary stages of cell growth. We found that Gis1 worked as a repressor during logarithmic phase, and as an activator during post diauxic shift and stationary phases of growth.