Analysis of the effects of chromatin modifying factors on the regulation of retrotransposon Ty2 transcription


Thesis Type: Postgraduate

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

Approval Date: 2005

Thesis Language: Turkish

Student: BÜKAY YENİCE

Supervisor: Sezai Türkel

Abstract:

Chromatin structure has the large effects on the regulation of gene expression in eukaryotes. Nucleosomes and non-histone proteins are the major factors that form highly ordered chromatin structures. Chromatin modifying complexes can alter the gene expression either by acting on the specific transcription factors or by changing the chromatin structure over the control regions of the target genes. In this study, the effects of chromatin modifying complexes on the transcription of retrotransposon Ty2-917 were investigated using Ty2-lacZ gene fusions and the specific mutant S. cerevisiae strains. Retrotransposons do not cause any disease but they have genetic similarities to pathogenic retroviruses. Hence, retrotransposon Ty2-917 has been extensively used as a good model system to analyze the control mechanisms of gene expression in retroviruses. Results of this thesis research indicated that the transcription of Ty2 is also regulated by chromatin modifying complexes. Lack of non-histone proteins and histone acetyl transferase activity resulted in several fold decrease in the transcription of Ty2-917. However, our results also showed that histone deacetylases have no effects on the Ty2917 transcription. In addition, results of this study also indicated that the some of the transcription mediators such as Med2p are essential for the transcriptional regulation of Ty2-917.