Analysis of the Effects of Chromatin Modifying Complexes on the Transcription of Retrotransposon Ty2-917 in Saccharomyces cerevisiae

Transcription of the yeast retrotransposon Ty2-917 is regulated by a complex set of regulatory regions located both upstream and downstream of the transcription initiation site. In this study, it was found that certain chromatin modifying factors are essential for the transcriptional regulation of Ty2-917. Among the chromatin binding factors tested in this research, non-histone proteins Nhp6A/B have the largest effect on the transcription of Ty2-917. In ∆nhp6A/B double mutant yeast strain transcription of Ty2 decreased 20-fold, indicating that these non-histone proteins are essential for the transcription of Ty2-917. Furthermore, it was also shown that the transcription of Ty2-917 decreased by 2-fold in the in ∆isw2 mutant, which shows that Isw2p is also involved in the activation of Ty2-917 transcription. In addition, results of this research show that the Spt7p, which is the critical subunit of SAGA complex, is essential for the maximal level transcription of Ty2-917.