Thoughts on Quorum Sensing and Fungal Dimorphism

Farnesol has been best studied for its role in regulating fungal dimorphism. However, farnesol is also a lipid and in this review we analyze data relevant to farnesol’s function and synthesis from the perspective of farnesol and bacterial endotoxins acting as membrane active compounds. This analysis implicates the possible roles of: (1) endotoxins in the regulation of farnesol production by C. albicans; (2) farnesol in the interactions between C. albicans and the host during disseminated infections; and (3) ubiquinones in the mechanisms for unusually high resistance to farnesol by some C. albicans cell types. Finally we discuss the implications that the use of farnesol as both a signaling molecule and to antagonize competing microbials species has for the regulation of HMG-CoA reductase, the enzyme that is the usual rate limiting step in sterol/ lipid synthesis.