How membrane lipids cross-talk with the cell wall: A study using sterol modified Pichia pastoris

Sterols are important lipids found in the membranes of most cells. They display unique structural and functional properties and the cellular ability to maintain proper sterol composition is critical for cell survival and fitness. Despite extensive studies, our understanding of how cells sense and respond to changes in sterol composition is very limited. Yeast cells producing cholesterol (the predominant sterol in mammals) instead of ergosterol (the predominant sterol in yeast) exhibit severe growth defects, protein mislocalization and abnormal cell wall morphologies, which is why these strains show high potential for further analysis of diverse response mechanisms to changes in sterol composition. Hence, we will make use of cholesterol producing Pichia pastoris strains to study the effect of these changes on diverse cellular stress response pathways. In particular, we will identify and further investigate the involvement and mechanism of plasma membrane stress sensors and signaling pathways and show, why and how lipid modifications may influence cell wall structures. Our results will be of major interest for research on lipid regulations and crosstalk between different cellular pathways, which could have an impact on the development of novel drugs targeting fungal membrane and/or cell wall. Applying P. pastoris in these studies will not only help reveal yet unknown mechanisms, but also promote the use of non-conventional yeasts to tackle scientific questions.

Young Researcher Group Principal Investigator Anita Emmerstorfer-Augustin in the spotlight