How does yeast respond to pressure?

Abstract

The brewing and baking yeast Saccharomyces cerevisiae has been used as a model for stress response studies of eukaryotic cells. In this review we focus on the effect of high hydrostatic pressure (HHP) on S. cerevisiae. HHP exerts a broad effect on yeast cells characteristic of common stresses, mainly associated with protein alteration and lipid bilayer phase transition. Like most stresses, pressure induces cell cycle arrest. Below 50 MPa (500 atm) yeast cell morphology is unaffected whereas above 220 MPa wild-type cells are killed. S. cerevisiae cells can acquire barotolerance if they are pretreated with a sublethal stress due to temperature, ethanol, hydrogen peroxide, or pressure. Nevertheless, pressure only leads to protection against severe stress if, after pressure pretreatment, the cells are also re-incubated at room pressure. We attribute this effect to the inhibition of the protein synthesis apparatus under HHP. The global genome expression analysis of S. cerevisiae cells submitted to HHP revealed a stress response profile. The majority of the up-regulated genes are involved in stress defense and carbohydrate metabolism while most repressed genes belong to the cell cycle progression and protein synthesis categories. However, the signaling pathway involved in the pressure response is still to be elucidated. Nitric oxide, a signaling molecule involved in the regulation of a large number of cellular functions, confers baroprotection. Furthermore, S. cerevisiae cells in the early exponential phase submitted to 50-MPa pressure show induction of the expression level of the nitric oxide synthase inducible isoform. As pressure becomes an important biotechnological tool, studies concerning this kind of stress in microorganisms are imperative.

Progress in Metabolic Engineering of Saccharomyces cerevisiae

“…Aside from high ethanol concentrations, yeast cells also must cope with several other types of stress during the process of bioethanol production, e.g., carbon dioxide (3) and pressure (85). Additionally osmotic stress is problematic, particularly in very-high-gravity fermentation (72), as is heat stress in areas/ seasons of high ambient temperature where cooling is unavailable or energetically undesirable (1).…”

Highlights of the 3rd International Conference on High Pressure Bioscience and Biotechnology

“…From these results, it was hypothesized that the cells try to compensate for the impaired membrane transport and translation by an up-regulation of some specific genes (16). Akin data were reported by Dr. Patricia Fernandes (UFES, Brazil) concerning Pressure Response in the Yeast Saccharomyces cerevisiae (18). While a pressure of 50 MPa did not induce visible cell damage or loss of viability, high hydrostatic pressure >100 MPa decreased cell viability and inactivated yeast cells at 220 MPa.…”

Insights into Responses to Extreme Environmental Conditions in Humans from Studies on Saccharomyces cerevisiae

“…HHP reduces fluidity of lipid molecules in the membrane; it induces conformational changes in DNA to convert it from the more common b-form to the denser Z-form and induces protein denaturation and reversible dissociation of protein complexes 18 . As a consequence of alterations in DNA conformation, DNA-protein interaction is perturbed which may influence processes that require DNA-protein association e.g., chromatin structure, replication, transcription, cell cycle progression and other associated processes.…”

“…Genome wide expression studies in S. cerevisiae cells exposed to hhp indicated that most of the up-regulated genes code for functions in carbohydrate metabolism and stress response functions. Given that hhp induces cell cycle arrest it was not surprising that the down-regulated genes code for proteins involved in cell cycle progression and protein synthesis 18 . The indicated studies also revealed that pressure-shock specific genes were also induced 19 .…”