title: The 14-3-3 Gene Function of Cryptococcus neoformans Is Required for its Growth and Virulence.
abstract: Cryptococcus neoformans is a life-threatening pathogenic yeast that causes devastating meningoencephalitis. The mechanism of cryptococcal brain invasion is largely unknown, and recent studies suggest that its extracellular microvesicles may be involved in the invasion process. The 14-3-3 protein is abundant in the extracellular microvesicles of C. neoformans, and the 14-3-3-GFP fusion has been used as the microvesicle's marker. However, the physiological role of 14-3-3 has not been explored. In this report, we have found that C. neoformans contains a single 14-3-3 gene that apparently is an essential gene. To explore the functions of 14-3-3, we substituted the promoter region of the 14-3-3 with the copper-controllable promoter CTR4. The CTR4 regulatory strain showed an enlarged cell size, drastic changes in morphology, and a decrease in the thickness of the capsule under copper-enriched conditions. Furthermore, the mutant cells produced a lower amount of total proteins in their extracellular microvesicles and reduced adhesion to human brain microvascular endothelial cells in vitro. Proteomic analyses of the protein components under 14-3-3-overexpressed and -suppressed conditions revealed that the 14-3-3 function(s) might be associated with the microvesicle biogenesis. Our results support that 14-3-3 has diverse pertinent roles in both physiology and pathogenesis in C. neoformans. Its gene functions are closely relevant to the pathogenesis of this fungus.
authors.affiliation: Divisions of Hematology-Oncology, The Saban Research Institute, Children's Hospital Los Angeles, Los Angeles, CA 90027, USA.
authors.forename: Jingbo
authors.initials: J
authors.lastname: Li
authors.affiliation: Laboratory of Clinical Infectious Diseases, National Institute of Allergy and Infectious Diseases, Bethesda, MD 20892, USA.|Infectious Diseases, The Saban Research Institute, Children's Hospital Los Angeles, Los Angeles, CA 90027, USA.
authors.forename: Yun C
authors.initials: YC
authors.lastname: Chang
authors.affiliation: Divisions of Hematology-Oncology, The Saban Research Institute, Children's Hospital Los Angeles, Los Angeles, CA 90027, USA.
authors.forename: Chun-Hua
authors.initials: CH
authors.lastname: Wu
authors.affiliation: Divisions of Hematology-Oncology, The Saban Research Institute, Children's Hospital Los Angeles, Los Angeles, CA 90027, USA.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Liu
authors.affiliation: Laboratory of Clinical Infectious Diseases, National Institute of Allergy and Infectious Diseases, Bethesda, MD 20892, USA.|Infectious Diseases, The Saban Research Institute, Children's Hospital Los Angeles, Los Angeles, CA 90027, USA.
authors.forename: Kyung J
authors.initials: KJ
authors.lastname: Kwon-Chung
authors.affiliation: Infectious Diseases, The Saban Research Institute, Children's Hospital Los Angeles, Los Angeles, CA 90027, USA.
authors.forename: Sheng-He
authors.initials: SH
authors.lastname: Huang
authors.affiliation: Pathology Department, The Saban Research Institute, Children's Hospital Los Angeles, Los Angeles, CA 90027, USA.
authors.forename: Hiro
authors.initials: H
authors.lastname: Shimada
authors.affiliation: Pathology Department, The Saban Research Institute, Children's Hospital Los Angeles, Los Angeles, CA 90027, USA.
authors.forename: Rob
authors.initials: R
authors.lastname: Fante
authors.affiliation: Pathology Department, The Saban Research Institute, Children's Hospital Los Angeles, Los Angeles, CA 90027, USA.
authors.forename: Xiaowei
authors.initials: X
authors.lastname: Fu
authors.affiliation: Divisions of Hematology-Oncology, The Saban Research Institute, Children's Hospital Los Angeles, Los Angeles, CA 90027, USA.
authors.forename: Ambrose
authors.initials: A
authors.lastname: Jong
mesh_terms: D048948:14-3-3 Proteins / Q000235:genetics* / Q000378:metabolism*; D000135:Acid Phosphatase / Q000378:metabolism; D015415:Biomarkers / Q000378:metabolism; D001921:Brain / Q000098:blood supply / Q000382:microbiology; D002448:Cell Adhesion / Q000502:physiology; D003300:Copper / Q000378:metabolism; D003455:Cryptococcus neoformans / Q000235:genetics* / Q000254:growth & development / Q000472:pathogenicity; D042783:Endothelial Cells / Q000382:microbiology; D062607:Fungal Capsules / Q000378:metabolism; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D042845:Laccase / Q000378:metabolism; D009154:Mutation; D010641:Phenotype; D011401:Promoter Regions, Genetic; D014774:Virulence; D037521:Virulence Factors / Q000235:genetics / Q000378:metabolism
chemical_list: D048948:14-3-3 Proteins; D015415:Biomarkers; D005656:Fungal Proteins; D037521:Virulence Factors; D003300:Copper; D042845:Laccase; D000135:Acid Phosphatase
keywords: 14-3-3; Cryptococcus neoformans; blood-brain barrier; brain invasion; microvesicles