Pressure-Dependent Gene Activation in Yeast Cells

Area of Science:

• Cellular physiology
• Molecular biology
• Biochemistry

Background:

• Hydrostatic pressure is a physical factor influencing cellular processes.
• Elevated hydrostatic pressure (tens of MPa) reduces yeast growth rate, while higher pressures (hundreds of MPa) decrease cellular viability.
• Understanding pressure-induced cellular damage, particularly to proteins, is crucial.

Purpose of the Study:

• To investigate the genome-wide gene expression changes in yeast cells exposed to varying hydrostatic pressures.
• To identify cellular components and pathways affected by hydrostatic pressure.
• To elucidate mechanisms of cellular adaptation and survival under pressure stress.

Main Methods:

• Yeast DNA microarrays were used to analyze gene expression profiles.
• Cells were exposed to different hydrostatic pressure conditions, including temporary adaptation (0.1-30 MPa and 30-0.1 MPa) and recovery from sublethal pressure (180 MPa at 4°C for 0 min; 40 MPa at 4°C for 16 h).
• Analysis focused on gene expression levels under pressure and during recovery phases.

Main Results:

• Temporary adaptation to both high and low pressures activated genes related to membrane and cell wall biosynthesis, suggesting these are pressure-sensitive targets.
• Gene expression analysis during recovery from sublethal pressure indicated the activation of proteasome activity and proteins in the endoplasmic reticulum.
• These findings suggest that proteasome function and endoplasmic reticulum proteins are critical for yeast survival after significant pressure exposure.

Conclusions:

• Hydrostatic pressure significantly affects yeast cellular physiology, impacting growth and viability.
• Pressure-induced damage likely targets proteins involved in membrane and cell wall biosynthesis.
• Proteasome activity and endoplasmic reticulum protein homeostasis are key factors for yeast cells to survive sublethal high-pressure treatments.