In Pseudomonas aeruginosa, diverse virulence determinants and secondary metabolites are regulated via the action of a hierarchical quorum-sensing system which integrates two chemically distinct classes of signal molecules, the N-acylhomoserine lactones (AHLs) and the 4-quinolones (4Qs). Synthesis of the pseudomonas quinolone signal, 2-heptyl-3-hydroxy-4-quinolone (PQS) depends on the pqsABCDE locus which is responsible for generating multiple 4Qs including 2-heptyl-4-quinolone (HHQ), the immediate PQS precursor. Exported HHQ is taken up by adjacent bacterial cells and converted into PQS by PqsH, a putative mono-oxygenase. In addition, PQS regulates its own production by driving the expression of pqsABCDE through a direct interaction with PqsR (MvfR). PQS regulates diverse target genes including those coding for elastase, rhamnolipid, the PA-IL lectin and pyocyanin via the action of PqsE as well as influencing biofilm development and impacting on cellular fitness. Furthermore, 4Q signalling is not restricted to P. aeruginosa raising the possibility of cross-talk with other related bacterial species which occupy similar ecological niches.

中文翻译：

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铜绿假单胞菌中的 4-喹诺酮信号：旧分子，新观点。

在铜绿假单胞菌中，多种毒力决定簇和次级代谢物通过分级群体感应系统的作用进行调节，该系统整合了两类化学上不同的信号分子，即 N-酰基高丝氨酸内酯 (AHL) 和 4-喹诺酮 (4Q)。假单胞菌喹诺酮信号 2-heptyl-3-hydroxy-4-quinolone (PQS) 的合成取决于 pqsABCDE 基因座，该基因座负责产生多个 4Q，包括直接 PQS 前体 2-heptyl-4-quinolone (HHQ)。输出的 HHQ 被相邻的细菌细胞吸收并通过 PqsH（一种假定的单加氧酶）转化为 PQS。此外，PQS 通过与 PqsR (MvfR) 的直接相互作用来驱动 pqsABCDE 的表达，从而调节其自身的生产。PQS 调节多种靶基因，包括编码弹性蛋白酶、鼠李糖脂、PA-IL 凝集素和绿脓素通过 PqsE 的作用以及影响生物膜的发育和对细胞适应性的影响。此外，4Q 信号不限于铜绿假单胞菌，这增加了与占据相似生态位的其他相关细菌物种发生串扰的可能性。