Molecular analysis of the apoptosis and autophagy signals on the gene expressions in Ty1 and Ty2 pseudoviruses

Sacchoromyces cerevisiae is a GRAS microorganisms used to study retrotranspozons. S. cerevisiae contains 5 different types of retrotransposon, known as Ty1-Ty5, in its genome. These retrotranspozons are also known as pseudoviruses because they are genomically similar to retroviruses. Their numbers are constant in the genome and have two open reading frames, called TYA and TYB. While TYA provides VLP formation, TYB forms reverse transcriptase, integrase and protease enzyme. The translation of TYB is done as TYA:TYB fusion protein, and this translational process occurs by ribosomal frameshift. There is no translation and transcription factors encoded from Ty genomes. All factors for transcription and translation use factors of S. cerevisiae, the host cell, similar to viruses. Therefore, the signals affecting yeast are thought to affect Ty elements as well. Apoptosis is a programmed cell death mechanism. Autophagy is a process that induces protein degradation and ensures cell balance. Apoptosis can be activated by acetic acid in yeast. Moreover, autophagy pathway can be activated by caffeine. Apoptosis and autophagy signals affects many different genes in S. cerevisiae. In this study, the effect of experimentally generated apoptosis and autophagy signals on transcription and ribosomal frameshift of Ty1 and Ty2 was studied in yeast. The study showed that apoptosis and autophagy signals affect the transcription of Ty1 and Ty2 pseudoviruses in mutant strains at different rates. Transcription of the Ty1 and Ty2 was determined to decrease with apoptosis and autophagy signaling. It was determined that ribosomal frameshift in Ty elements decreased by 50% with selective autophagy types.