Details

Autor(en) / Beteiligte

• Georg, Jens
• Kostova, Gergana
• Vuorijoki, Linda
• Schön, Verena
• Kadowaki, Taro
• Huokko, Tuomas
• Baumgartner, Desirée
• Müller, Maximilian
• Klähn, Stephan
• Allahverdiyeva, Yagut
• Hihara, Yukako
• Futschik, Matthias E.
• Aro, Eva-Mari
• Hess, Wolfgang R.

Titel

Acclimation of Oxygenic Photosynthesis to Iron Starvation Is Controlled by the sRNA IsaR1

Ist Teil von

• Current biology, 2017-05, Vol.27 (10), p.1425-1436.e7

Ort / Verlag

England: Elsevier Ltd

Erscheinungsjahr

2017

Link zum Volltext

Quelle

Free E-Journal (出版社公開部分のみ）

Beschreibungen/Notizen

• Oxygenic photosynthesis crucially depends on proteins that possess Fe2+ 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 Fe2+-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. [Display omitted] •IsaR1 controls the synthesis of photosynthetic electron transport components•IsaR1 maintains the regulation of Fe/S cluster biogenesis when iron is limiting•Synthesis of chlorophylls, heme, and phycocyanin is controlled at an early step•IsaR1 plays a major role in the response to iron starvation Oxygenic photosynthesis requires iron cofactors, making photosynthetic cells one of the most iron-rich cellular systems. Georg et al. show that the cyanobacterial sRNA IsaR1 is induced under iron starvation and then acts on the photosynthetic apparatus in three specific ways. IsaR1 controls a complex network relevant for acclimation to low iron.