Pessi G, Haas D
Laboratoire de Biologie Microbienne, Université de Lausanne, CH-1015 Lausanne, Switzerland.
FEMS Microbiol Lett. 2001 Jun 12;200(1):73-8. doi: 10.1111/j.1574-6968.2001.tb10695.x.
The global response regulator GacA of Pseudomonas aeruginosa PAO1 positively controls the production of the quorum sensing signal molecule N-butanoyl-homoserine-lactone (C4-HSL) and hence the synthesis of several C4-HSL-dependent virulence factors, including hydrogen cyanide (HCN). This study presents evidence that GacA positively influences the transcription of the rhlI gene, specifying C4-HSL synthase, explaining the quorum sensing-dependent transcriptional control of the HCN biosynthetic genes (hcnABC). In addition, GacA was found to modulate hcn gene expression positively at a post-transcriptional level involving the hcnA ribosome-binding site. Thus, the activating effect of GacA on cyanogenesis results from both transcriptional and post-transcriptional mechanisms.
铜绿假单胞菌PAO1的全局响应调节因子GacA正向调控群体感应信号分子N-丁酰基高丝氨酸内酯（C4-HSL）的产生，从而调控包括氰化氢（HCN）在内的几种C4-HSL依赖性毒力因子的合成。本研究表明，GacA正向影响指定C4-HSL合酶的rhlI基因的转录，解释了HCN生物合成基因（hcnABC）的群体感应依赖性转录调控。此外，发现GacA在涉及hcnA核糖体结合位点的转录后水平上正向调节hcn基因表达。因此，GacA对氰化物生成的激活作用源于转录和转录后机制。
