Bax expression protects yeast plasma membrane against ethanol-induced permeabilization

Area of Science:

• * Molecular biology
• * Cell biology
• * Biochemistry

Background:

• * The pro-apoptotic protein Bax plays a crucial role in programmed cell death in higher eukaryotes.
• * Its precise mechanism of action, particularly its effects on membrane permeability, remains incompletely understood.
• * Yeast serves as a model organism to investigate fundamental cellular processes due to its genetic tractability and conserved pathways.

Purpose of the Study:

• * To elucidate the mechanism by which the pro-apoptotic protein Bax induces cell death in yeast.
• * To investigate the role of plasma membrane permeabilization and lipid oxidation in Bax-mediated yeast cell death.
• * To establish yeast as a model system for studying Bax's effects on membrane properties.

Main Methods:

• * Yeast cells were engineered to express the pro-apoptotic protein Bax.
• * Plasma membrane permeabilization was assessed using propidium iodide staining.
• * Cellular responses were analyzed under varying conditions, including ethanol stress, aeration, fatty acid manipulation, and resveratrol treatment.

Main Results:

• * Bax expression induced yeast cell death, but notably prevented ethanol stress-induced plasma membrane permeabilization.
• * These Bax-mediated effects were modulated by aeration, fatty acid unsaturation, and the lipid oxidation inhibitor resveratrol.
• * Data indicate a direct impact of Bax on plasma membrane permeability and suggest involvement of lipid oxidation.

Conclusions:

• * Bax directly affects plasma membrane permeability in yeast, independent of ethanol-induced stress.
• * Lipid oxidation plays a significant role in mediating Bax's effects on yeast cells.
• * Yeast provides a valuable model for dissecting the molecular mechanisms of Bax-induced membrane alterations.