Purification and characterization of an autoregulatory substance capable of regulating the morphological transition in Candida albicans

The yeast Candida albicans has a distinguishing feature, dimorphism, which is the ability to switch between two morphological forms: a budding yeast f orm and a multicellular invasive filamentous form. This ability has been po stulated to contribute to the virulence of this organism. Studies on the mo rphological transition from a filamentous to a budding yeast form in C. alb icans have shown that this organism excretes an autoregulatory substance in to the culture medium. This substance was extracted and purified by normal- phase and reversed-phase HPLC. The autoregulatory substance was structurall y identified as 3,7,11-trimethyl-2,6,10-dodecatrienoate (farnesoic acid) by NMR and mass spectrometry. Growth experiments suggest that this substance does not inhibit yeast cell growth but inhibits filamentous growth. These f indings have implications for developmental signaling by the fungus and mig ht have medicinal value in the development of antifungal therapies.