The regulatory networks involved in the uptake and metabolism of different nitrogen sources in response to their availability are crucial in all organisms. Nitrogen metabolism pathways have been studied in detail in archaea such as the extreme halophilic archaeon Haloferax mediterranei. However, knowledge about nitrogen metabolism regulation in haloarchaea is very scarce, and no transcriptional regulators involved in nitrogen metabolism have been identified to date. Advances in the molecular biology field have revealed that many small RNAs (sRNAs) are involved in the regulation of a diverse metabolic pathways. Surprisingly, no studies on regulation mediated by sRNAs have focused on the response to environmental fluctuations in nitrogen in haloarchaea. To identify sRNAs involved in the transcriptional regulation of nitrogen assimilation genes in Haloferax mediterranei and, thus, propose a novel regulatory mechanism, RNA-Seq was performed using cells grown in the presence of two different nitrogen sources. The differential transcriptional expression analysis of the RNA-Seq data revealed differences in the transcription patterns of 102 sRNAs according to the nitrogen source, and the molecular functions, cellular locations and biological processes with which the target genes were associated were predicted. These results enabled the identification of four sRNAs that could be directly related to the regulation of genes involved in nitrogen metabolism. This work provides the first proposed regulatory mechanism of nitrogen assimilation-related gene expression by sRNAs in haloarchaea as an alternative to transcriptional regulation mediated by proteins.

中文翻译：

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极端嗜盐古细菌Haloferax mediterranei中小RNA调控氮代谢的新提议。

响应于氮的可用性而参与吸收和代谢不同氮源的调控网络在所有生物中都至关重要。氮代谢途径已在古细菌中进行了详细研究，例如极端嗜盐古细菌Haloferax mediterranei。但是，关于卤古菌中氮代谢调控的知识非常稀少，迄今为止，尚未发现涉及氮代谢的转录调控因子。分子生物学领域的进展表明，许多小RNA（sRNA）参与了多种代谢途径的调控。出人意料的是，尚无关于sRNA介导的调控的研究集中于对盐生古细菌中氮环境波动的响应。为了鉴定嗜盐哈弗氏菌中氮同化基因的转录调控所涉及的sRNA，并因此提出了一种新的调控机制，使用在两种不同氮源存在下生长的细胞进行了RNA-Seq的调控。RNA-Seq数据的差异转录表达分析显示，根据氮源，102个sRNA的转录模式存在差异，并预测了与目标基因相关的分子功能，细胞位置和生物学过程。这些结果使得能够鉴定出四种可能与氮代谢相关基因的调节直接相关的sRNA。