Fig. 6.

Calcium and the calcineurin pathway are required for improved survival on caspofungin, but not on hydroxyurea. (A) Parental strain SC5314 was plated (∼10⁶ cells per plate) onto YPD supplemented with HU (2.814mg/ml) or CSP (100 ng/ml) alone, or in combination with calcium chloride (100 mM) or inhibitors of the calcineurin pathway, FK506 (0.5 µg/ml) and cyclosporin A (CsA) (0.5 µg/ml), as indicated. (B) Parental strains YJBT545 and YJBT736, and isogenic derivatives lacking genes CNA1, CNB1 (encoding calcineurin subunits) or CRZ1 (encoding a transcription factor downstream of the calcineurin pathway) were plated on YPD plates supplemented with HU (2.814mg/ml) or CSP (100 ng/ml) at 37 °C for 3 days. Note that growth on CSP, but not HU, is enhanced with added calcium and inhibited both by inhibitors of, and mutants affecting, the calcineurin pathway.