Central role for ferritin in the day/night regulation of iron homeostasis in marine phytoplankton

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 112; no. 47; pp. 14652 - 14657
• Main Authors: Botebol, Hugo, Lesuisse, Emmanuel, Šuták, Robert, Six, Christophe, Lozano, Jean-Claude, Schatt, Philippe, Vergé, Valérie, Kirilovsky, Amos, Morrissey, Joe, Léger, Thibaut, Camadro, Jean-Michel, Gueneugues, Audrey, Bowler, Chris, Blain, Stéphane, Bouget, François-Yves
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences 24-11-2015; National Acad Sciences
• Subjects: Biochemistry, Molecular Biology; Biological Sciences; Biotechnology; Blotting, Western; Chemical Precipitation; Circadian Rhythm - drug effects; Circadian Rhythm - genetics; Circadian Rhythm - radiation effects; Ferritins - genetics; Ferritins - metabolism; Gene Expression Regulation - drug effects; Gene Expression Regulation - radiation effects; Homeostasis; Homeostasis - drug effects; Homeostasis - genetics; Homeostasis - radiation effects; Iron; Iron - metabolism; Iron - pharmacology; Iron-Binding Proteins - metabolism; Kinetics; Life Sciences; Light; Mass Spectrometry; Microbial Viability - drug effects; Microbial Viability - radiation effects; Microbiology and Parasitology; Ostreococcus; Photosynthesis; Phytoplankton - drug effects; Phytoplankton - genetics; Phytoplankton - growth & development; Phytoplankton - metabolism; Plankton; Proteins; Seawater - microbiology; Transcriptome - genetics; phytoplankton; iron; circadian; ferritin; Ostreococcus
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.1506074112

In large regions of the open ocean, iron is a limiting resource for phytoplankton. The reduction of iron quota and the recycling of internal iron pools are among the diverse strategies that phytoplankton have evolved to allow them to grow under chronically low ambient iron levels. Phytoplankton species also have evolved strategies to cope with sporadic iron supply such as long-term storage of iron in ferritin. In the picophytoplanktonic speciesOstreococcuswe report evidence from observations both in the field and in laboratory cultures that ferritin and the main ironbinding proteins involved in photosynthesis and nitrate assimilation pathways show opposite diurnal expression patterns, with ferritin being maximally expressed during the night. Biochemical and physiological experiments using a ferritin knock-out line subsequently revealed that this protein plays a central role in the diel regulation of iron uptake and recycling and that this regulation of iron homeostasis is essential for cell survival under iron limitation.