The Role of Zinc in Gliotoxin Biosynthesis of Aspergillus fumigatus.
Int J Mol Sci
; 20(24)2019 Dec 08.
Article
en En
| MEDLINE
| ID: mdl-31817957
ABSTRACT
Zinc performs diverse physiological functions, and virtually all living organisms require zinc as an essential trace element. To identify the detailed function of zinc in fungal pathogenicity, we carried out cDNA microarray analysis using the model system of Aspergillus fumigatus, a fungal pathogen. From microarray analysis, we found that the genes involved in gliotoxin biosynthesis were upregulated when zinc was depleted, and the microarray data were confirmed by northern blot analysis. In particular, zinc deficiency upregulated the expression of GliZ, which encodes a Zn2-Cys6 binuclear transcription factor that regulates the expression of the genes required for gliotoxin biosynthesis. The production of gliotoxin was decreased in a manner inversely proportional to the zinc concentration, and the same result was investigated in the absence of ZafA, which is a zinc-dependent transcription activator. Interestingly, we found two conserved ZafA-binding motifs, 5'-CAAGGT-3', in the upstream region of GliZ on the genome and discovered that deletion of the ZafA-binding motifs resulted in loss of ZafA-binding activity; gliotoxin production was decreased dramatically, as demonstrated with a GliZ deletion mutant. Furthermore, mutation of the ZafA-binding motifs resulted in an increase in the conidial killing activity of human macrophage and neutrophil cells, and virulence was decreased in a murine model. Finally, transcriptomic analysis revealed that the expression of ZafA and GliZ was upregulated during phagocytosis by macrophages. Taken together, these results suggest that zinc plays an important role in the pathogenicity of A. fumigatus by regulating gliotoxin production during the phagocytosis pathway to overcome the host defense system.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Aspergillus fumigatus
/
Zinc
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Proteínas Fúngicas
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Regulación Fúngica de la Expresión Génica
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Gliotoxina
Tipo de estudio:
Prognostic_studies
Límite:
Animals
/
Humans
Idioma:
En
Revista:
Int J Mol Sci
Año:
2019
Tipo del documento:
Article