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oai:gredos.usal.es:10366/1460722025-04-30T19:41:52Zcom_10366_4028com_10366_3947com_10366_3946com_10366_3823com_10366_110570com_10366_4576col_10366_4029col_10366_110571

00925njm 22002777a 4500 dc Vicentefranqueira, Rocío author Leal Sánchez, Fernando author Marín, Laura author Sánchez Suárez, Clara Inés author Calera Abad, José Antonio author 2019-04 [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. Vicentefranqueira, R., Leal, F., Marín, L., Sánchez, C.I. and Calera, J.A. (2019), 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. Environmental Microbiology, 21: 2787-2808. https://doi.org/10.1111/1462-2920.14618o 1462-2912 http://hdl.handle.net/10366/146072 10.1111/1462-2920.14618 1462-2920 Aspergillus fumigatus ZafA Immunosuppressed hosts Organic material Ions Zn2 Iron 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