The Small Regulatory RNA SyR1/PsrR1 Controls Photosynthetic Functions in Cyanobacteria
The Small Regulatory RNA SyR1/PsrR1 Controls Photosynthetic Functions in Cyanobacteria
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DOI：
10.1105/tpc.114.129767
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发表时间：
2014-09-01
期刊：
影响因子：
11.6
通讯作者：
Wilde, Annegret
中科院分区：
文献类型：
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作者：
Georg, Jens;Dienst, Dennis;Wilde, Annegret
到目前为止，人们对植物、藻类或蓝藻中光合作用的RNA调节知之甚少。小RNA PsrR1(以前的SyR1)已在聚球藻PCC6803中被发现，并在蓝藻门中被广泛保守。PsrR1的表达是在从中等光照条件转变为强光条件后不久诱导的。在适度光照条件下，PsrR1的人工过表达导致了一种漂白表型。高级计算目标预测表明，PsrR1可以控制几个与光合作用相关的mRNAs，这一发现得到了聚球藻PCC6803中这种小RNA脉冲过表达的转录组分析实验结果的支持。我们在一个异源报告系统中通过突变分析证实了PsrR1与PSAL、PSAJ、chlN和CPCA mRNAs的核糖体结合区之间的相互作用。以PSAL为特异性靶点，我们发现只有在PsrR1存在的情况下，PSAL mRNA才能被RNase E处理。此外，我们为PsrR1在不同环境条件下对PSAL的转录后调控提供了证据，并分析了基于PsrR1的调控对光系统I的影响。综上所述，计算和实验数据一致地确立了小RNA PsrR1是控制光合作用功能的调节因子。
Little is known so far about RNA regulators of photosynthesis in plants, algae, or cyanobacteria. The small RNA PsrR1 (formerly SyR1) has been discovered in Synechocystis sp PCC 6803 and appears to be widely conserved within the cyanobacterial phylum. Expression of PsrR1 is induced shortly after a shift from moderate to high-light conditions. Artificial overexpression of PsrR1 led to a bleaching phenotype under moderate light growth conditions. Advanced computational target prediction suggested that several photosynthesis-related mRNAs could be controlled by PsrR1, a finding supported by the results of transcriptome profiling experiments upon pulsed overexpression of this small RNA in Synechocystis sp PCC 6803. We confirmed the interaction between PsrR1 and the ribosome binding regions of the psaL, psaJ, chlN, and cpcA mRNAs by mutational analysis in a heterologous reporter system. Focusing on psaL as a specific target, we show that the psaL mRNA is processed by RNase E only in the presence of PsrR1. Furthermore, we provide evidence for a posttranscriptional regulation of psaL by PsrR1 in the wild type at various environmental conditions and analyzed the consequences of PsrR1-based regulation on photosystem I. In summary, computational and experimental data consistently establish the small RNA PsrR1 as a regulatory factor controlling photosynthetic functions.