title: A P4-ATPase subunit of the Cdc50 family plays a role in iron acquisition and virulence in Cryptococcus neoformans.
abstract: The pathogenic fungus Cryptococcus neoformans delivers virulence factors such as capsule polysaccharide to the cell surface to cause disease in vertebrate hosts. In this study, we screened for mutants sensitive to the secretion inhibitor brefeldin A to identify secretory pathway components that contribute to virulence. We identified an ortholog of the cell division control protein 50 (Cdc50) family of the noncatalytic subunit of type IV P-type ATPases (flippases) that establish phospholipid asymmetry in membranes and function in vesicle-mediated trafficking. We found that a cdc50 mutant in C. neoformans was defective for survival in macrophages, attenuated for virulence in mice and impaired in iron acquisition. The mutant also showed increased sensitivity to drugs associated with phospholipid metabolism (cinnamycin and miltefosine), the antifungal drug fluconazole and curcumin, an iron chelator that accumulates in the endoplasmic reticulum. Cdc50 is expected to function with catalytic subunits of flippases, and we previously documented the involvement of the flippase aminophospholipid translocases (Apt1) in virulence factor delivery. A comparison of phenotypes with mutants defective in genes encoding candidate flippases (designated APT1, APT2, APT3, and APT4) revealed similarities primarily between cdc50 and apt1 suggesting a potential functional interaction. Overall, these results highlight the importance of membrane composition and homeostasis for the ability of C. neoformans to cause disease.
authors.affiliation: Michael Smith Laboratories, Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC, Canada.
authors.forename: Guanggan
authors.initials: G
authors.lastname: Hu
authors.affiliation: Michael Smith Laboratories, Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC, Canada.
authors.forename: Mélissa
authors.initials: M
authors.lastname: Caza
authors.affiliation: Michael Smith Laboratories, Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC, Canada.|Institute of Microbiology, Zurich, Switzerland.
authors.forename: Erik
authors.initials: E
authors.lastname: Bakkeren
authors.affiliation: Michael Smith Laboratories, Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC, Canada.
authors.forename: Matthias
authors.initials: M
authors.lastname: Kretschmer
authors.affiliation: Michael Smith Laboratories, Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC, Canada.
authors.forename: Gaurav
authors.initials: G
authors.lastname: Bairwa
authors.affiliation: Michael Smith Laboratories, Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC, Canada.
authors.forename: Ethan
authors.initials: E
authors.lastname: Reiner
authors.affiliation: Michael Smith Laboratories, Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC, Canada.
authors.forename: James
authors.initials: J
authors.lastname: Kronstad
mesh_terms: D000818:Animals; D000935:Antifungal Agents / Q000494:pharmacology; D001430:Bacteriocins / Q000494:pharmacology; D020126:Brefeldin A / Q000494:pharmacology; D002455:Cell Division / Q000502:physiology; D002462:Cell Membrane / Q000378:metabolism*; D003453:Cryptococcosis / Q000382:microbiology / Q000473:pathology; D003455:Cryptococcus neoformans / Q000378:metabolism / Q000472:pathogenicity*; D003474:Curcumin / Q000494:pharmacology; D004721:Endoplasmic Reticulum / Q000378:metabolism; D005260:Female; D015725:Fluconazole / Q000494:pharmacology; D062610:Fungal Polysaccharides / Q000378:metabolism; D005656:Fungal Proteins / Q000235:genetics*; D007501:Iron / Q000378:metabolism*; D008264:Macrophages / Q000382:microbiology; D051379:Mice; D008807:Mice, Inbred BALB C; D000073779:P-type ATPases / Q000235:genetics / Q000378:metabolism*; D010456:Peptides, Cyclic / Q000494:pharmacology; D049294:Phospholipid Transfer Proteins / Q000235:genetics*; D010767:Phosphorylcholine / Q000031:analogs & derivatives / Q000494:pharmacology; D014774:Virulence / Q000235:genetics; D037521:Virulence Factors / Q000235:genetics / Q000378:metabolism
chemical_list: D000935:Antifungal Agents; D001430:Bacteriocins; D062610:Fungal Polysaccharides; D005656:Fungal Proteins; D010456:Peptides, Cyclic; D049294:Phospholipid Transfer Proteins; D037521:Virulence Factors; D010767:Phosphorylcholine; C000485:cinnamycin; D020126:Brefeldin A; C039128:miltefosine; D015725:Fluconazole; D007501:Iron; C000625878:Cdc50 protein, Cryptococcus neoformans; D000073779:P-type ATPases; D003474:Curcumin
keywords: antifungal drug; curcumin; flippase; heme; pathogenesis; secretion; vein-type ore