FIG 7.

Schematic diagram of a mechanism of CZ66 eliminating FLC tolerance of C. albicans. (A) Ergosterol is important for the cell membrane integrity of C. albcians. (B) FLC targets the C14α-demethylase (Erg11) and consequently results in ergosterol depletion and accumulation of 14α-methylsterols, such as 14α-methyl-3-6-diol. These 14α-methylsterols replace ergosterol, resulting in a functionally maintained C. albicans cell membrane and making C. albicans survive in the presence of FLC. (C) The deletion of the ERG3 gene leads to the loss of 14α-methyl-3-6-diol, but accumulated 14α-methylfecosterol is sufficient to maintain C. albicans cell membrane functionally. (D) The ERG251 gene deletion or CZ66 inhibits the activity of Erg251 and obtusifoliol will not be produced for the synthesis of 14α-methylsterols. This leads to the absence of 14α-methylsterols as a substitute for ergosterol to maintain cell membrane integrity and, consequently, makes C. albicans inviable in the presence of FLC.