# Mild Heat Stress Alters the Physical State and Structure of Membranes in Triacylglycerol-Deficient Fission Yeast, Schizosaccharomyces pombe

## TL;DR

This study shows that triacylglycerol metabolism helps protect cell membranes in fission yeast during mild heat stress.

## Contribution

The study reveals that triacylglycerol-deficient fission yeast cells are less able to adjust membrane properties under heat stress.

## Key findings

- Membrane structures like lipid droplets and vacuoles were affected in mutants under heat stress.
- Triacylglycerol-deficient cells produced less HSP16 and trehalose, which protect against heat.
- Wild-type cells adjusted membrane properties better than mutants during thermal stress.

## Abstract

We investigated whether the elimination of two major enzymes responsible for triacylglycerol synthesis altered the structure and physical state of organelle membranes under mild heat shock conditions in the fission yeast, Schizosaccharomyces pombe. Our study revealed that key intracellular membrane structures, lipid droplets, vacuoles, the mitochondrial network, and the cortical endoplasmic reticulum were all affected in mutant fission yeast cells under mild heat shock but not under normal growth conditions. We also obtained direct evidence that triacylglycerol-deficient cells were less capable than wild-type cells of adjusting their membrane physical properties during thermal stress. The production of thermoprotective molecules, such as HSP16 and trehalose, was reduced in the mutant strain. These findings suggest that an intact system of triacylglycerol metabolism significantly contributes to membrane protection during heat stress.