AIMS: The present work aimed at identifying the metabolic response to acid stress and the mechanisms that lead to cell tolerance and adaptation. METHODS AND RESULTS: Two strategies were used: screening deletion mutants for cell growth at neutral and acid pH compared to wild type and measurement by qPCR of the expression of yeast genes involved in different pathways. CONCLUSIONS: The results complement our previous findings and showed that the Cell Wall Integrity pathway is the main mechanism for cell tolerance to acid pH, and this damage triggers the protein kinase C (PKC) pathway mainly via the Wsc1p membrane sensor. In addition, cell wall injury might mimic the effects of high osmotic shock and activates the High Osmolarity Glycerol pathway, which amplifies the signal in the upper part of PKC pathway and leads to the activation of Ca(2+) channels by SLT2 overexpression and this Ca(2+) influx further activates calcineurin. Together, these mechanisms induce the expression of genes involved in cell cycle regulation and cell wall regeneration. SIGNIFICANCE AND IMPACT OF THE STUDY: These interactions are responsible for long-term adaptation of yeast cells to the acidic environment, and the results could drive future work on the genetic modification of yeast strains for high tolerance to the stresses of the bioethanol fermentation process.
AIMS: The present work aimed at identifying the metabolic response to acid stress and the mechanisms that lead to cell tolerance and adaptation. METHODS AND RESULTS: Two strategies were used: screening deletion mutants for cell growth at neutral and acid pH compared to wild type and measurement by qPCR of the expression of yeast genes involved in different pathways. CONCLUSIONS: The results complement our previous findings and showed that the Cell Wall Integrity pathway is the main mechanism for cell tolerance to acid pH, and this damage triggers the protein kinase C (PKC) pathway mainly via the Wsc1p membrane sensor. In addition, cell wall injury might mimic the effects of high osmotic shock and activates the High Osmolarity Glycerol pathway, which amplifies the signal in the upper part of PKC pathway and leads to the activation of Ca(2+) channels by SLT2 overexpression and this Ca(2+) influx further activates calcineurin. Together, these mechanisms induce the expression of genes involved in cell cycle regulation and cell wall regeneration. SIGNIFICANCE AND IMPACT OF THE STUDY: These interactions are responsible for long-term adaptation of yeast cells to the acidic environment, and the results could drive future work on the genetic modification of yeast strains for high tolerance to the stresses of the bioethanol fermentation process.
Authors: Carolina Elsztein; Rita de Cássia Pereira de Lima; Will de Barros Pita; Marcos Antonio de Morais Journal: Curr Microbiol Date: 2016-05-31 Impact factor: 2.188
Authors: Arun S Rajkumar; Guodong Liu; David Bergenholm; Dushica Arsovska; Mette Kristensen; Jens Nielsen; Michael K Jensen; Jay D Keasling Journal: Nucleic Acids Res Date: 2016-06-20 Impact factor: 16.971
Authors: Harley O'Connor Mount; Nicole M Revie; Robert T Todd; Kaitlin Anstett; Cathy Collins; Michael Costanzo; Charles Boone; Nicole Robbins; Anna Selmecki; Leah E Cowen Journal: PLoS Genet Date: 2018-04-27 Impact factor: 5.917
Authors: Daniel González-Ramos; Marcel van den Broek; Antonius Ja van Maris; Jack T Pronk; Jean-Marc G Daran Journal: Biotechnol Biofuels Date: 2013-04-03 Impact factor: 6.040