Thesis Type: Postgraduate
Institution Of The Thesis: Bursa Uludağ University, Fen Bilimleri Enstitüsü, Turkey
Approval Date: 2021
Thesis Language: Turkish
Student: Thomas Saah Peters
Supervisor: SEZAİ TÜRKELAbstract:
Saccharomyces cerevisiae is a unicellular eukaryotic organism that can be found as haploid or diploid. Although it has a single cell, it shows different developmental processes under the influence of some environmental conditions. These processes are sporulation and pseudohyphal developments. It is known that nitrogen starvation in diploid yeasts is controlled by the Ras2 membrane protein. The Ras2 protein, which is activated in nitrogen starvation, changes the activity of many genes encoding enzymes and transcription factors through the protein kinase A pathway. As a result, diploid yeasts change their growth pattern and pass on to pseudohyphal reproduction. Sigma strain with ras2 and some other mutations produces pseudohyphae even though it is haploid. Trehalose is an important disaccharide and storage carbohydrate for S.cerevisiae. Although it is a stress protection factor, it controls the entry of glucose into the cell. TPS1 and NTH1 genes also encode enzymes that function in biosynthesis and catabolism in trehalose metabolism. In this thesis study, the effects of different cellular processes such as apoptosis, autophagy, pseudohyphal development seen in S. cerevisiae on the transcription of TPS1 and NTH1 genes were investigated. The transcription levels of TPS1-LacZ and NTH1-LacZ gene fusions transformed into strains with different genetic characteristics were determined by the β-galactosidase enzyme assay method. When the apoptosis conditions were activated, it was observed that TPS1 and NTH1 gene expression was suppressed 2-fold. However, different levels of activation were found in both TPS1 and NTH1 gene transcription by activating autophagy conditions. A significant decrease in NTH1 gene transcription in sporulation activation in diploid yeast cell was determined. It is seen that NTH1 and TPS1 gene transcriptions are affected differently by different cellular development or differentiation processes of S. cerevisiae.