Sahar Hasim, Elyse N. Vaughn, Dallas Donohoe, Donna M. Gordon, Susan Pfiffner, Todd B. Reynolds
Candida albicans is the most common human fungal pathogen. The ability to undergo the morphological transition from yeast to hyphal growth is critical for its pathogenesis. Farnesol, a precursor in the isoprenoid/sterol pathway, is a quorum-sensing molecule produced by C. albicans that inhibits hyphal growth in this polymorphic fungus. Interestingly, C. albicans can tolerate farnesol concentrations that are toxic to other fungi. We hypothesized that changes in phospholipid composition are one of the factors contributing to farnesol tolerance in C. albicans. In this study, we found that loss of enzymes that synthesize the phospholipids phosphatidylserine (PS) and/or phosphatidylethanolamine (PE) compromise the tolerance of C. albicans to farnesol. Compared to wild-type, the phospholipid mutant cho1Δ/Δ (loss of PS and decreased PE synthesis) shows greater inhibition of growth, loss of ATP production, increased consumption of oxygen, and increased formation of reactive oxygen species (ROS) in the presence of farnesol (FOH). The cho1Δ/Δ mutant also exhibits decreased sensitivity to mitochondrial ATPase inhibition, suggesting that cells lacking PS and/or downstream PE rely less on mitochondrial function for ATP synthesis. These data reveal that PS and PE play roles in farnesol tolerance and maintaining mitochondrial respiratory function.
Hasim S, Vaughn EN, Donohoe D, Gordon DM, Pfiffner S, Reynolds TB. 2018. Influence of phosphatidylserine and phosphatidylethanolamine on farnesol tolerance in Candida albicans. Yeast 35:343-351.