Taxonomic group: fungi / Basidiomycota
(Phylum: Basidiomycota)
Organ / tissue: capsuleAssociated disease: infection due to Cryptococcus gattii [ICD11:
XN0LE 
]
The structure was elucidated in this paperNCBI PubMed ID: 29897877Publication DOI: 10.1128/mSphere.00023-18Journal NLM ID: 101674533Publisher: Washington, DC: American Society for Microbiology
Correspondence: Kmetzsch L <liviak
cbiot.ufrgs.br>
Institutions: Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil, Laboratório de Fungos de Importância Médica e Biotecnológica, Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil, Laboratório de Biologia Celular de Leveduras Patogênicas, Instituto de Microbiologia Paulo de Goés, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil, Departamento de Biologia e Farmácia, Universidade de Santa Cruz do Sul (UNISC), Programa de Pós-Graduação em Promoção da Saúde, Santa Cruz do Sul, Brazil, Centro de Desenvolvimento Tecnológico em Saúde, Fundação Oswaldo Cruz, Fiocruz, Rio de Janeiro, Brazil, Departamento de Biologia Molecular e Biotecnologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
The yeast-like pathogen Cryptococcus gattii is an etiological agent of cryptococcosis. The major cryptococcal virulence factor is the polysaccharide capsule, which is composed of glucuronoxylomannan (GXM), galactoxylomannan (GalXM), and mannoproteins (MPs). The GXM and GalXM polysaccharides have been extensively characterized; however, there is little information about the role of mannoproteins in capsule assembly and their participation in yeast pathogenicity. The present study characterized the function of a predicted mannoprotein from C. gattii, designated Krp1. Loss-of-function and gain-of-function mutants were generated, and phenotypes associated with the capsular architecture were evaluated. The null mutant cells were more sensitive to a cell wall stressor that disrupts β-glucan synthesis. Also, these cells displayed increased GXM release to the culture supernatant than the wild-type strain did. The loss of Krp1 influenced cell-associated cryptococcal polysaccharide thickness and phagocytosis by J774. A1 macrophages in the early hours of interaction, but no difference in virulence in a murine model of cryptococcosis was observed. In addition, recombinant Krp1 was antigenic and differentially recognized by serum from an individual with cryptococcosis, but not with serum from an individual with candidiasis. Taken together, these results indicate that C. gattii Krp1 is important for the cell wall structure, thereby influencing capsule assembly, but is not essential for virulence in vivo. IMPORTANCE Cryptococcus gattii has the ability to escape from the host's immune system through poorly understood mechanisms and can lead to the death of healthy individuals. The role of mannoproteins in C. gattii pathogenicity is not completely understood. The present work characterized a protein, Kpr1, that is essential for the maintenance of C. gattii main virulence factor, the polysaccharide capsule. Our data contribute to the understanding of the role of Kpr1 in capsule structuring, mainly by modulating the distribution of glucans in C. gattii cell wall.
capsular polysaccharide, mannoprotein, Cryptococcus gattii
Structure type: structural motif or average structure
Location inside paper: p.2, paragraph 2, GXM
Compound class: O-polysaccharide, glucuronoxylomannan
Contained glycoepitopes: IEDB_114701,IEDB_115136,IEDB_115576,IEDB_130701,IEDB_140116,IEDB_140630,IEDB_144983,IEDB_145668,IEDB_152206,IEDB_164174,IEDB_167188,IEDB_174332,IEDB_2270799,IEDB_423153,IEDB_76933,IEDB_983930,SB_197,SB_44,SB_67,SB_72
Methods: biological assays, DLS
Biosynthesis and genetic data: biochemical data
Comments, role: higher amounts of GXM are detected in Δkrp1 mutant compared to WT strain
NCBI Taxonomy refs (TaxIDs): 294750,
1859096Reference(s) to other database(s): GTC:G39597XD
Show glycosyltransferases
There is only one chemically distinct structure:
Found 
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(later renamed to: Cryptococcus gattii VGII R265)