دورية
The sRNA NsiR4 fine-tunes arginine synthesis in the cyanobacterium Synechocystissp. PCC 6803 by post-transcriptional regulation of PirA
| العنوان: | The sRNA NsiR4 fine-tunes arginine synthesis in the cyanobacterium Synechocystissp. PCC 6803 by post-transcriptional regulation of PirA |
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| المؤلفون: | Bolay, Paul, Hemm, Luisa, Florencio, Francisco J., Hess, Wolfgang R., Muro-Pastor, M. Isabel, Klähn, Stephan |
| المصدر: | RNA Biology; December 2022, Vol. 19 Issue: 1 p811-818, 8p |
| مستخلص: | ABSTRACTAs the only oxygenic phototrophs among prokaryotes, cyanobacteria employ intricate mechanisms to regulate common metabolic pathways. These mechanisms include small protein inhibitors exerting their function by protein–protein interaction with key metabolic enzymes and regulatory small RNAs (sRNAs). Here we show that the sRNA NsiR4, which is highly expressed under nitrogen limiting conditions, interacts with the mRNA of the recently described small protein PirA in the model strain Synechocystissp. PCC 6803. In particular, NsiR4 targets the pirA5ʹUTR close to the ribosome binding site. Heterologous reporter assays confirmed that this interaction interferes with pirAtranslation. PirA negatively impacts arginine synthesis under ammonium excess by competing with the central carbon/nitrogen regulator PIIthat binds to and thereby activates the key enzyme of arginine synthesis, N-acetyl-L-glutamate-kinase (NAGK). Consistently, ectopic nsiR4expression in Synechocystisresulted in lowered PirA accumulation in response to ammonium upshifts, which also affected intracellular arginine pools. As NsiR4 and PirA are inversely regulated by the global nitrogen transcriptional regulator NtcA, this regulatory axis enables fine tuning of arginine synthesis and conveys additional metabolic flexibility under highly fluctuating nitrogen regimes. Pairs of small protein inhibitors and of sRNAs that control the abundance of these enzyme effectors at the post-transcriptional level appear as fundamental building blocks in the regulation of primary metabolism in cyanobacteria. |
| قاعدة البيانات: | Supplemental Index |
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Full Text Finder | تدمد: | 15476286 15558584 |
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| DOI: | 10.1080/15476286.2022.2082147 |