Tup1 is critical for transcriptional repression in Quiescence in S. cerevisiae

Abstract

Upon glucose starvation, S. cerevisiae shows a dramatic alteration in transcription, resulting in wide-scale repression of most genes and activation of some others. This coincides with an arrest of cellular proliferation. A subset of such cells enters quiescence, a reversible non-dividing state. Here, we demonstrate that the conserved transcriptional corepressor Tup1 is critical for transcriptional repression after glucose depletion. We show that Tup1-Ssn6 binds new targets upon glucose depletion, where it remains as the cells enter the G0 phase of the cell cycle. In addition, we show that Tup1 represses a variety of glucose metabolism and transport genes. We explored how Tup1 mediated repression is accomplished and demonstrated that Tup1 coordinates with the Rpd3L complex to deacetylate H3K23. We found that Tup1 coordinates with Isw2 to affect nucleosome positions at glucose transporter HXT family genes during G0. Finally, microscopy revealed that a quarter of cells with a Tup1 deletion contain multiple DAPI puncta. Taken together, these findings demonstrate the role of Tup1 in transcriptional reprogramming in response to environmental cues leading to the quiescent state.

Implications of carbon catabolite repression for Aspergillus‐based cell factories: A review

“…Indeed, recent studies have found that Tup1‐Ssn6 is transcriptionally associated with the hxt gene, which to some extent supports this view that SsnF promotes the transcription of different genes under different carbon source conditions. [ 104 ] For example, in high glucose environments, SsnF promotes the expression of creA , creB , and creC , while under low glucose conditions, SsnF promotes the production of hydrolases independently of CreA. [ 103 ] These inferences need to be verified by further research.…”

Revealing Potential Genes Affecting Flocculation and/or Viability of Saccharomyces pastorianus by Comparative Genomic Analysis

“…18,19 RNA-Seq data analysis has demonstrated that Tup1 acts as an inhibitor in the regulation of genes associated with yeast entry into the stationary phase. 20 Furthermore, the involvement of signaling pathways such as PKA, Ras, and Snf1 in the regulation of yeast flocculation has been demonstrated, suggesting a potential correlation between the yeast flocculation ability and viability.…”

“…As yeast cells reach saturation in liquid medium and conventional nutrients are depleted, they enter a quiescence phase . This process is primarily regulated by nutrient-sensing signaling pathways, including TOR, PKA, Ras, Sch9, and Snf1. , RNA-Seq data analysis has demonstrated that Tup1 acts as an inhibitor in the regulation of genes associated with yeast entry into the stationary phase . Furthermore, the involvement of signaling pathways such as PKA, Ras, and Snf1 in the regulation of yeast flocculation has been demonstrated, suggesting a potential correlation between the yeast flocculation ability and viability.…”