The link between yeast cell wall porosity and plasma membrane permeability after PEF treatment

Arunas Stirke,Nerija Zurauskiene,Aldas Dervinis,Povilas Simonis,Saulius Balevicius,Aurelijus Zimkus,Raimonda Celiesiute-Germaniene,Arunas Ramanavicius

doi:10.1038/s41598-019-51184-y

Arunas Stirke, Nerija Zurauskiene + Show 6 more

Open Access

https://doi.org/10.1038/s41598-019-51184-y

Copy DOI

Journal: Scientific Reports	Publication Date: Oct 14, 2019
Citations: 33	License type: open-access

Affiliation: Center for Physical Sciences and Technology

Abstract

An investigation of the yeast cell resealing process was performed by studying the absorption of the tetraphenylphosphonium (TPP+) ion by the yeast Saccharomyces cerevisiae. It was shown that the main barrier for the uptake of such TPP+ ions is the cell wall. An increased rate of TPP+ absorption after treatment of such cells with a pulsed electric field (PEF) was observed only in intact cells, but not in spheroplasts. The investigation of the uptake of TPP+ in PEF treated cells exposed to TPP+ for different time intervals also showed the dependence of the absorption rate on the PEF strength. The modelling of the TPP+ uptake recovery has also shown that the characteristic decay time of the non-equilibrium (PEF induced) pores was approximately a few tens of seconds and this did not depend on the PEF strength. A further investigation of such cell membrane recovery process using a florescent SYTOX Green nucleic acid stain dye also showed that such membrane resealing takes place over a time that is like that occurring in the cell wall. It was thus concluded that the similar characteristic lifetimes of the non-equilibrium pores in the cell wall and membrane after exposure to PEF indicate a strong coupling between these parts of the cell.

Highlights

The molecules, which enter cells such as yeast or bacteria, must pass through the cell wall, a periplasmic space and obtain access to the transporters located in the plasma membrane
Our previous work demonstrated that the permeability to the lipophilic ion tetraphenylphosphonium (TPP+) across the yeast cell membrane and cell wall may be reversibly changed by their exposure to pulsed electric field (PEF) of microsecond duration[8]
The ability of the yeast cells to accumulate the TPP+ ions was investigated by measuring the kinetics of the TPP+ absorption by the cells not treated with the electric field

Summary

Introduction

The molecules, which enter cells such as yeast or bacteria, must pass through the cell wall, a periplasmic space and obtain access to the transporters located in the plasma membrane. There are many ways to regulate (mainly to increase) the rate at which these various molecules can pass the cell wall barrier This can be done by using chemical treatment with organic solvents and detergents[10] or by mechanical shearing or treatment with a pulsed electric field (PEF), generating pores[11]. Besides simple diffusion, when gasses and small lipophilic molecules are being transported, yeast cells have many instruments (transporters and channels) to preserve cell homeostasis[12] This is the reason why the lipid bilayer is always confronted with hyper osmotic pressure at the interior of the cell due to the impermeable intracellular compounds. One method was based on the study of the TPP+ ion absorption kinetics using a potentiometric ion selective electrode, which provides data about the yeast cell wall permeabilization Another method, based on fluorescent dye measurements, showed the permeabilized state of the cell membrane. Experiments and modeling have shown a strong link between the yeast cell membrane and the wall resealing process after PEF action

Methods

Results

Conclusion