title: Cryptococcus neoformans Ca(2+)  homeostasis requires a chloride channel/antiporter Clc1 in JEC21, but not in H99.
abstract: CLC-type chloride/proton antiporters are required for copper/iron homeostasis in fungi. A relationship between CLCs and Ca(2+)  homeostasis has not been found before. Here we demonstrate the requirement of the antiporter CLC1 for Ca(2+)  homeostasis/signaling in Cryptococcus neoformans. The deletion of CLC1 in JEC21 resulted in a mutant hypersensitive to cyclosporine A, an inhibitor of calcineurin. Intracellular Ca(2+)  deficiency in the mutant Tx1 was confirmed with Fluo-3 staining epi-fluorescence microscopy. Tx1 failed to grow at elevated temperature and in SDS and displayed defects in cell wall integrity and cell separation. This defective phenotype is because of Ca(2+)  deficiency that was restorable by exogenous Ca(2+) . In contrast, H99 CLC1 was dispensable for Ca(2+)  homeostasis and had no comparable defective consequences if deleted, suggesting divergent roles of CLCs in Ca(2+)  homeostasis. Distinct Ca(2+)  homeostasis mechanisms may contribute the virulence difference between the two strains. This work reveals a novel action of CLC antiporters in fungi and may provide information as to the evolution of pathogenicity among cryptococcal strains.
authors.affiliation: National Key Program of Microbiology and Department of Microbiology, College of Life Sciences, Nankai University, Tianjin, China.
authors.forename: Dong
authors.initials: D
authors.lastname: Li
authors.forename: Xiaojiao
authors.initials: X
authors.lastname: Zhang
authors.forename: Zhongming
authors.initials: Z
authors.lastname: Li
authors.forename: Jiao
authors.initials: J
authors.lastname: Yang
authors.forename: Jiao
authors.initials: J
authors.lastname: Pan
authors.forename: Xudong
authors.initials: X
authors.lastname: Zhu
mesh_terms: D000935:Antifungal Agents / Q000378:metabolism; D017920:Antiporters / Q000235:genetics / Q000378:metabolism*; D065095:Calcineurin Inhibitors; D002118:Calcium / Q000378:metabolism*; D002473:Cell Wall / Q000378:metabolism; D018118:Chloride Channels / Q000235:genetics / Q000378:metabolism*; D003455:Cryptococcus neoformans / Q000187:drug effects / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D016572:Cyclosporine / Q000378:metabolism; D017353:Gene Deletion; D006706:Homeostasis; D012967:Sodium Dodecyl Sulfate / Q000378:metabolism
chemical_list: D000935:Antifungal Agents; D017920:Antiporters; D065095:Calcineurin Inhibitors; D018118:Chloride Channels; D012967:Sodium Dodecyl Sulfate; D016572:Cyclosporine; D002118:Calcium