Biophysical Society Conference | Tahoe 2024

Molecular Biophysics of Membranes

Poster Abstracts

32-POS Board 18 INVESTIGATING HOW HOPANOIDS MAINTAIN FUNCTIONAL EUKARYOTIC MEMBRANE PROPERTIES DURING HYPOXIA. Harry Thorne 1 ; Maria Makarova 1 ; 1 University of Birmingham, Institute of Metabolism and Systems Research (IMSR), Birmingham , United Kingdom Sterols are highly important membrane constituents that are critical for maintaining the integrity and functional biophysical properties of eukaryotic membranes. Through lipid-lipid interactions, sterols play pivotal roles in modulating the fluidity, permeability, lipid organisation and phase behaviour of membranes. However, sterol biosynthesis can only occur in the presence of molecular oxygen. Therefore, this poses the question of how, in the absence of oxygen, can functional eukaryotic membrane properties be maintained. Here, we investigate how the biosynthesis of hopanoids, a class of cyclic triterpenoids with structural similarities to eukaryotic sterols, facilitates the sterol-independent anaerobic growth of the fission yeast Schizosaccharomyces japonicus. This study aims to determine whether diploptene and diplopterol can functionally compensate for the absence of ergosterol through imparting similar membrane properties. We will employ advanced microscopy and polarity sensitive probes to quantitatively characterise the level by which hopanoids, and ergosterol, induce order within eukaryotic model membranes, both in vitro and in vivo. Using genetic tools and antifungal drugs, membrane lipid compositions of live cells can be carefully manipulated, allowing for differential measurements of lipid order, induced by hopanoids and/or ergosterol, to be linked to cell fitness. The expected significance from this study will aid our understanding of how novel, non canonical eukaryotic lipids can be leveraged for environmental adaptation to oxygen availability and antifungal drugs.

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