Pulsed electric field-mediated elimination of yeast [ PSI + ] prion is variant dependent and affects cell growth dynamics

Yeast Saccharomyces cerevisiae is a widespread model system in which mechanisms of prion induction and elimination have been identified. New and safe substances and methods are being sought to eliminate prions from cells. In this research, we applied guanidinium hydrochloride (GuHCl) alone and in combination with pulsed electric field treatment against [ PSI + ] prion. The analysis of cell culture optical density and doubling time showed that the method of [ PSI + ] prion elimination increases cell doubling time, with combined treatment having a more severe impact on cell growth than GuHCl treatment alone. Additionally, we found that both elimination methods can impact the optical culture density achieved by [ psi − ] cells. However, the cells in which the [ PSI + ] prion has been eliminated by GuHCl alone are able to reach the same optical density as unaffected [ psi − ] cells and a higher optical density than the affected [ psi − ] cells by GuHCl alone. These findings suggest that the presence and subsequent removal of the [ PSI + ] prion influence early exponential growth, revealing lasting effects on cell growth dynamics that are distinct from previously reported effects on stationary phase survival. This work highlights how prion elimination strategies, including chemical and electric field treatments, can impact post-curing growth behavior in yeast cells.