FIG 8.

Model of the caspofungin resistance mechanism in C. neoformans. Caspofungin (CAS) treatment activates the Ca²⁺-calcineurin pathway, which regulates downstream targets that regulate cell wall integrity and drug resistance. In the wild type (WT), Cdc50 may coordinate Ca²⁺ efflux, which in conjunction with Crm1 plays roles in Ca²⁺ influx processes to maintain intracellular calcium homeostasis. An excessive elevation of intracellular calcium levels the in cdc50Δ mutant induces cell death. Loss of Crm1 in the cdc50Δ mutant alleviates the increased calcium levels. TF, transcription factor.