Iron economy in Naegleria gruberi reflects its metabolic flexibility. Issue 9 (August 2018)

• Record Type: Journal Article
• Authors: Mach, Jan; Bíla, Jarmila; Ženíšková, Kateřina; Arbon, Dominik; Malych, Ronald; Glavanakovová, Marie; Nývltová, Eva; Sutak, Robert
• Is Part Of: International journal for parasitology. Volume 48:Issue 9/10(2018)
• Page Start: 719
• Page End: 727
• Publication Date: 2018-08
• Subjects: Naegleria -- Metabolism -- Iron -- Ferritin -- Hemerythrin; Parasitology -- Periodicals; Parasitology -- Periodicals; Parasitologie -- Périodiques; Parasitology; Periodicals; Electronic journals; 571.999
• DOI: 10.1016/j.ijpara.2018.03.005
• Languages: English
• ISSNs: 0020-7519

Abstract

Graphical abstract: Highlights: Naegleria gruberi ferritin is localised to the mitochondria only. Hemerythrin and hydrogenase are highly down-regulated under iron-limited conditions. The respiration rate does not change under iron-limited conditions. Mitochondria and ferritin are key players in iron homeostasis. Abstract: Naegleria gruberi is a free-living amoeba, closely related to the human pathogen Naegleria fowleri, the causative agent of the deadly human disease primary amoebic meningoencephalitis. Herein, we investigated the effect of iron limitation on different aspects of N. gruberi metabolism. Iron metabolism is among the most conserved pathways found in all eukaryotes. It includes the delivery, storage and utilisation of iron in many cell processes. Nevertheless, most of the iron metabolism pathways of N. gruberi are still not characterised, even though iron balance within the cell is crucial. We found a single homolog of ferritin in the N. gruberi genome and showed its localisation in the mitochondrion. Using comparative mass spectrometry, we identified 229 upregulated and 184 down-regulated proteins under iron-limited conditions. The most down-regulated protein under iron-limited conditions was hemerythrin, and a similar effect on the expression of hemerythrin was found in N. fowleri . Among the other down-regulated proteins were [FeFe]-hydrogenase and its maturase HydG and several heme-containing proteins. The activities of [FeFe]-hydrogenase, as well as alcohol dehydrogenase, were also decreased by iron deficiency. Our results indicate that N. gruberi is able to rearrange its metabolism according to iron availability, prioritising mitochondrial pathways. We hypothesise that the mitochondrion is the center for iron homeostasis in N. gruberi, with mitochondrially localised ferritin as a potential key component of this process.