The interplay between zinc and iron homeostasis in Aspergillus fumigatus under zinc-replete conditions relies on the iron-mediated regulation of alternative transcription units of zafA and the basal amount of the ZafA zinc-responsiveness transcription factor
[EN] Aspergillus fumigatus is a saprophyte fungus that typically grows on organic decaying matter but can also parasitize immunosuppressed hosts. This is explained, in part, by its great ability to take up Zn2+ ions from living tissues, which is induced by the ZafA transcription factor. This study s...
| Autores: | , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2019 |
| País: | España |
| Institución: | Universidad de Salamanca (USAL) |
| Repositorio: | GREDOS. Repositorio Institucional de la Universidad de Salamanca |
| OAI Identifier: | oai:gredos.usal.es:10366/146072 |
| Acceso en línea: | http://hdl.handle.net/10366/146072 |
| Access Level: | acceso abierto |
| Palabra clave: | Aspergillus fumigatus ZafA Immunosuppressed hosts Organic material Ions Zn2 Iron 2414 Microbiología |
| Sumario: | [EN] Aspergillus fumigatus is a saprophyte fungus that typically grows on organic decaying matter but can also parasitize immunosuppressed hosts. This is explained, in part, by its great ability to take up Zn2+ ions from living tissues, which is induced by the ZafA transcription factor. This study shows that the ZafA-mediated regulation of fungal growth is also influenced by iron availability and that A. fumigatus is well adapted to grow in zinc-limiting and zinc-replete media with Zn:Fe ratios lower in the former than in the latter. Accordingly, this indicates that iron availability appears to be more critical for fungal growth in zinc-replete than in zinc-limiting environments. Interestingly, the cross-regulation of zinc/iron homeostasis under zinc-replete conditions relies on an unprecedented iron-mediated regulation of different zafA transcription units that, along with a limited transcript translation, allows synthesizing the right basal amount of ZafA dependent on iron availability. We posit that this regulatory strategy has evolved in fungi as a mechanism to adjust zinc intake to iron availability under zinc-replete conditions. Thus, fungal growth is enhanced in zinc- and iron-replete media but restricted by reducing zinc intake under iron starvation to prevent the noxious side effects of an intracellular zinc excess during iron deficiency. |
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