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Browsing by Author "Allahverdiyeva, Yagut"

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  • Acclimation of oxygenic photosynthesis to iron starvation is controlled by the sRNA IsaR1
    Publication . Georg, Jens; Kostova, Gergana; Vuorijoki, Linda; Schoen, Verena; Kadowaki, Taro; Huokko, Tuomas; Baumgartner, Desiree; Mueller, Maximilian; Klaehn, Stephan; Allahverdiyeva, Yagut; Hihara, Yukako; Futschik, Matthias; Aro, Eva-Mari; Hess, Wolfgang R.
    Oxygenic photosynthesis crucially depends on proteins that possess Fe (2+) or Fe/S complexes as co-factors or prosthetic groups. Here, we show that the small regulatory RNA (sRNA) IsaR1 (Iron-Stress-Activated RNA 1) plays a pivotal role in acclimation to low-iron conditions. The IsaR1 regulon consists of more than 15 direct targets, including Fe (2+)-containing proteins involved in photosynthetic electron transfer, detoxification of anion radicals, citrate cycle, and tetrapyrrole biogenesis. IsaR1 is essential for maintaining physiological levels of Fe/S cluster biogenesis proteins during iron deprivation. Consequently, IsaR1 affects the acclimation of the photosynthetic apparatus to iron starvation at three levels: (1) directly, via posttranscriptional repression of gene expression; (2) indirectly, via suppression of pigment; and (3) Fe/S cluster biosynthesis. Homologs of IsaR1 are widely conserved throughout the cyanobacterial phylum. We conclude that IsaR1 is a critically important riboregulator. These findings provide a new perspective for understanding the regulation of iron homeostasis in photosynthetic organisms.
    2017-05Journal article Open Access Show more