The ethanol disturbs the cell cycle, transcription, translation, protein folding, cell wall, membranes, and many Saccharomyces cerevisiae metabolic processes. Long non-coding RNAs (lncRNAs) are regulatory molecules binding onto the genome or proteins. The number of lncRNAs described for yeast is still scarce, and little is known concerning their roles in the system. There is a lack of knowledge concerning how lncRNAs are responsive to the ethanol tolerance in yeast and whether they act in this tolerance. Hence, by using RNA-Seq data from S. cerevisiae strains with different ethanol tolerance phenotypes, we found the severe ethanol responsive lncRNAs. We modeled how they participate in the ethanol tolerance by analyzing lncRNA-protein interactions. The results showed that the EtOH tolerance responsive lncRNAs, in both higher tolerant and lower tolerant phenotypes, work on different pathways: cell wall, cell cycle, growth, longevity, cell surveillance, ribosome biogenesis, intracellular transport, trehalose metabolism, transcription, and nutrient shifts. In summary, lncRNAs seems to interconnect essential systems modules to overcome the ethanol stress. Finally, here we also found the most extensive catalog of lncRNAs in yeast.

Ethanol impairs many subsystems of Saccharomyces cerevisiae, including the cell cycle. Cyclins and damage checkpoints drive the cell cycle. Two ethanol-responsive lncRNAs in yeast interact with cell cycle proteins, and here we investigated the role of these RNAs on the ethanol-stressed cell cycle. Our network dynamic modeling showed that the higher and lower ethanol tolerant strains undergo a cell cycle arrest during the ethanol stress. However, lower tolerant phenotype arrest in a later phase leading to its faster population rebound after the stress relief. Two lncRNAs can skip the arrests mentioned. The in silico overexpression of lnc9136 of SEY6210 (a lower tolerant strain), and CRISPR-Cas9 partial deletions of this lncRNA, evidenced that the one induces a regular cell cycle even under ethanol stress; this lncRNA binds to Gin4 and Hsl1, driving the Swe1p, Clb1/2, and cell cycle. Moreover, the lnc10883 of BY4742 (a higher tolerant strain) interacts to the Mec1p and represses Bub1p, circumventing the DNA and spindle damage checkpoints keeping a normal cell cycle even under DNA damage. Overall, we present the first evidence of the direct roles of lncRNAs on cell cycle proteins, the dynamics of this system in different ethanol tolerant phenotypes, and a new cell cycle model.