Shi Mengliang, Chen Lei, Zhang Weiwen
Laboratory of Synthetic Microbiology, School of Chemical Engineering & Technology, Tianjin University, Tianjin, China.
Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering, Ministry of Education of China, Tianjin, China.
Front Microbiol. 2020 Mar 17;11:403. doi: 10.3389/fmicb.2020.00403. eCollection 2020.
Two-component signal transduction systems are still poorly functionally characterized in the model cyanobacterium sp. PCC 6803. To address the issue, a GC-MS based comparative metabolomic analysis was conducted on a library of 44 knockout mutants for the response regulators (RRs) in . The metabolomic profiling analysis showed that 7 RRs mutants, namely Δ, Δ, Δ, Δ, Δ, Δ, and Δ, were significantly different at metabolomic level, although their growth patterns are similar to the wild type under the normal autotrophic growth condition, suggesting regulatory diversity of RRs at metabolite level in . Additionally, a detailed metabolomic analysis coupled with RT-PCR verification led to useful clues for possible function of these 7 RRs, which were found involved in regulation of multiple aspects of cellular metabolisms in . Moreover, an integrative metabolomic and evolutionary analysis of all RR showed that four groups of RR genes clustered together in both metabolomic and evolutionary trees, suggesting of possible functional conservation of these RRs during the evolutionary process. Meanwhile, six groups of RRs with close evolutionary origin were found with different metabolomic profiles, suggesting possible functional changes during evolution. In contrast, more than 10 groups of RR genes with different clustering patterns in the evolutionary tree were found clustered together in metabolomics-based tree, suggesting possible functional convergences during the evolution. This study provided a metabolomic view of RR function, and the most needed functional clues for further characterization of these regulatory proteins in .
在模式蓝藻聚球藻属PCC 6803中，双组分信号转导系统的功能特性仍知之甚少。为了解决这个问题，我们对该属中44个响应调节因子（RRs）基因敲除突变体文库进行了基于气相色谱-质谱联用的比较代谢组学分析。代谢组学分析表明，7个RRs突变体，即Δ、Δ、Δ、Δ、Δ、Δ和Δ，在代谢组水平上有显著差异，尽管它们在正常自养生长条件下的生长模式与野生型相似，这表明该属中RRs在代谢物水平上具有调控多样性。此外，详细的代谢组学分析结合逆转录-聚合酶链反应验证，为这7个RRs的可能功能提供了有用线索，发现它们参与了该属细胞代谢多个方面的调控。此外，对所有RRs进行的综合代谢组学和进化分析表明，四组RR基因在代谢组学和进化树中聚集在一起，这表明这些RRs在进化过程中可能具有功能保守性。同时，发现六组具有相近进化起源的RRs具有不同的代谢组学谱，表明在进化过程中可能发生了功能变化。相反，在进化树中具有不同聚类模式的10多组RR基因在基于代谢组学的树中聚集在一起，表明在进化过程中可能发生了功能趋同。本研究提供了RR功能的代谢组学观点，以及该属中这些调节蛋白进一步表征最需要的功能线索。
