Moonlighting proteins are variably exposed at the cell surfaces of Candida glabrata, Candida parapsilosis and Candida tropicalis under certain growth conditions

• Published in: BMC microbiology Vol. 19; no. 1; p. 149
• Main Authors: Karkowska-Kuleta, Justyna, Satala, Dorota, Bochenska, Oliwia, Rapala-Kozik, Maria, Kozik, Andrzej
• Format: Journal Article
• Language: English
• Published: England BioMed Central Ltd 03.07.2019; BioMed Central; BMC
• Subjects: Candida; Candida glabrata - growth & development; Candida glabrata - metabolism; Candida parapsilosis - growth & development; Candida parapsilosis - metabolism; Candida tropicalis - growth & development; Candida tropicalis - metabolism; Candidiasis; Cell Membrane - metabolism; Cell surface proteome; Cell wall; Cell Wall - metabolism; Culture Media - chemistry; Enolase; Environmental quality; Environmental research; Fungal Proteins - metabolism; Fungi; Glyceraldehyde-3-Phosphate Dehydrogenase (Phosphorylating) - metabolism; Liquid chromatography; Microorganisms; Monosaccharides; Mycoses; Non-albicans Candida species; Pathogenic microorganisms; Phosphates; Phosphopyruvate Hydratase - metabolism; Polysaccharides; Proteins; Proteome; Pyruvate Decarboxylase - metabolism; Trypsin; Trypsin - metabolism; Candidiasis; Non-albicans Candida species; Enolase; Cell surface proteome; Cell wall
• ISSN: 1471-2180; 1471-2180
• DOI: 10.1186/s12866-019-1524-5

Adaptability to different environmental conditions is an essential characteristic of pathogenic microorganisms as it facilitates their invasion of host organisms. The most external component of pathogenic yeast-like fungi from the Candida genus is the multilayered cell wall. This structure is composed mainly of complex polysaccharides and proteins that can undergo dynamic changes to adapt to the environmental conditions of colonized niches. We utilized cell surface shaving with trypsin and a shotgun proteomic approach to reveal the surface-exposed proteins of three important non-albicans Candida species-C. glabrata, C. parapsilosis and C. tropicalis. These proteinaceous components were identified after the growth of the fungal cells in various culture media, including artificial saliva, artificial urine and vagina-simulative medium under aerobic conditions and anaerobically in rich YPD medium. Several known proteins involved in cell wall maintenance and fungal pathogenesis were identified at the cell surface as were a number of atypical cell wall components-pyruvate decarboxylase (Pdc11), enolase (Eno1) and glyceraldehyde-3-phosphate dehydrogenase (Tdh3) which are so-called 'moonlighting' proteins. Notably, many of these proteins showed significant upregulation at the cell surface in growth media mimicking the conditions of infection compared to defined synthetic medium. Moonlighting proteins are expressed under diverse conditions at the cell walls of the C. glabrata, C. parapsilosis and C. tropicalis fungal pathogens. This indicates a possible universal surface-associated role of these factors in the physiology of these fungi and in the pathology of the infections they cause.