Investigation of the effects of different signaling pathways to gene expression in retrovirus Ty1


Thesis Type: Doctorate

Institution Of The Thesis: Bursa Uludağ University, Fen Bilimleri Enstitüsü, Biyoloji , Turkey

Approval Date: 2014

Thesis Language: Turkish

Student: ELİF ARİK

Supervisor: Sezai Türkel

Abstract:

The yeast retrotranspozon Ty1 belongs to retroviridae group and propagates with a retroviral-like mechanism within yeast cells. Ty1 does not encodes any transcription factors and hence its transcriptional regulation is completely depends on the yeast encoded factors. In this study, we have analyzed the transcriptional response to glucose signaling and osmotic stress of retrotransposon Ty1 in haploid and diploid cells. The transcription levels of Ty1 decreased at least 3-fold in haploid tup1 mutant S. cerevisiae cells. However, Ty1 transcription levels in homozygous tup1 mutant diploid S. cerevisiae cells were similar with Ty1 transcription levels of wild-type diploid cells. The correlation of transcription levels in repressed, derepressed and osmotic stress conditions indicate that Tup1p involves regulation of Ty1 transcription in response to glucose signaling and osmotic stress. Ty1 transcription is not regulated in response to glucose signaling and osmotic stress in haploid cells. In contrast to this, Ty1 transcription is regulated in response to glucose signaling and osmotic stress in diploid cells and these regulations depend on Tup1p. Moreover Tup1p requires Snf2p and partially Ada2p for Ty1 transcription. The transcription levels of Ty1 decreased at least 3-fold in haploid tec1 mutant S. cerevisiae cells. Though Hog1p and Skn7p is not essential for the regulation of Ty1 transcription in response to osmotic stress, Skn7p activates Ty1 transcription at least 2-fold.