A new Pseudomonas quinolone signal (PQS) binding partner: MexG.
A new Pseudomonas quinolone signal (PQS) binding partner: MexG.
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DOI：
10.1039/c5sc04197j
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发表时间：
2016-04-21
期刊：
影响因子：
8.4
通讯作者：
Welch M
中科院分区：
文献类型：
--
作者：
Hodgkinson JT;Gross J;Baker YR;Spring DR;Welch M
假单胞菌喹诺酮信号 (PQS) 探针捕获该信号分子的新结合伴侣。机会性病原体铜绿假单胞菌利用称为群体感应的细胞间信号传导机制来调节毒力。铜绿假单胞菌产生两种基于喹诺酮的群体感应信号分子；假单胞菌喹诺酮信号 (PQS) 及其生物合成前体 2-庚基-4(1H)-喹诺酮 (HHQ)。迄今为止，仅鉴定出一种能够结合 PQS 和 HHQ 的受体（PqsR 蛋白）。在这里，我们报告了用于化学蛋白质组学研究的 PQS 和 HHQ 亲和探针的合成。 PQS 亲和探针在体外非常有效地捕获 PqsR。此外，我们还发现了 PQS 和“孤儿”RND 外排泵蛋白 MexG 之间的相互作用。通过纯化 MexG 并表征其体外结合 PQS 和 HHQ 的能力，进一步证实了 PQS-MexG 相互作用。我们的研究结果表明，PQS 可能在细胞中具有多个结合伙伴，并为研究铜绿假单胞菌和其他生物体中的喹诺酮信号传导提供了重要的新工具。
Pseudomonas Quinolone Signal (PQS) probes capture a new binding partner for this signal molecule. The opportunistic pathogen Pseudomonas aeruginosa utilises the cell–cell signalling mechanism known as quorum sensing to regulate virulence. P. aeruginosa produces two quinolone-based quorum sensing signalling molecules; the Pseudomonas quinolone signal (PQS) and its biosynthetic precursor 2-heptyl-4(1H)-quinolone (HHQ). To date, only one receptor (the PqsR protein) has been identified that is capable of binding PQS and HHQ. Here, we report on the synthesis of PQS and HHQ affinity probes for chemical proteomic studies. The PQS affinity probe very effectively captured PqsR in vitro. In addition, we also identified an interaction between PQS and the “orphan” RND efflux pump protein, MexG. The PQS–MexG interaction was further confirmed by purifying MexG and characterizing its ability to bind PQS and HHQ in vitro. Our findings suggest that PQS may have multiple binding partners in the cell and provide important new tools for studying quinolone signalling in P. aeruginosa and other organisms.