7. International Molecular Biology and Biotechnology Congress (MOLBIOTECH), Konya, Turkey, 25 - 27 April 2018, vol.1, no.1, pp.1
Trehalose is deposited by Saccharomyces cerevisiae as a storage carbohydrate and as a stress protectant. The regulation of trehalose level in yeast cell is strictly controlled by trehalose synthesis and degrading enzymes. The biosynthesis of trehalose is catalyzed by TPS complex and the breakdown of trehalose is catalyzed by neutral trehalase enzyme. The trehalose content of yeast cells increases in response to nutrient starvation and different environmental stresses. Mig1 and Mig2 are zinc-finger DNA binding transcription factors that are involved in glucose repression. Nrg1 and Nrg2 repressor proteins have also zinc-finger DNA binding domain in order to bind STRE and PDS elements on the promoters. Both Mig1/2 and Nrg1/2 are involved in regulation of genes controlled by glucose. In our research, the effect of Mig1/2 and Nrg1/2 repressor proteins on the accumulation of trehalose were investigated by using Δmig1, Δmig2, Δnrg1, Δnrg2 mutants and their isogenic wild-type yeast strain. The trehalose content of exponentially growing Δmig1 yeast cells was 6 fold higher than that of wild type and other mutant yeast cells. Nitrogen starvation triggered trehalose accumulation both in wild type and mutant yeast cells except Δmig1 mutant cells. Also the trehalose content of Δmig2, Δnrg1 and Δnrg2 mutant yeast cells were 3-4 times higher than wild type in nitrogen deprivation. These results showed that Mig1 transcription factor is essential for maintainence of trehalose level both in standart and stress conditions, while Mig2, Nrg1 and Nrg2 repressor proteins are essential under stress conditions.