PA2663 (PpyR) increases biofilm formation in Pseudomonas aeruginosa PAO1 through the psl operon and stimulates virulence and quorum-sensing phenotypes
PA2663 (PpyR) increases biofilm formation in Pseudomonas aeruginosa PAO1 through the psl operon and stimulates virulence and quorum-sensing phenotypes
复制标题
DOI：
10.1007/s00253-007-1308-y
复制
发表时间：
2008-02-01
影响因子：
5
通讯作者：
Wood, Thomas K.
中科院分区：
文献类型：
--
作者：
Attila, Can;Ueda, Akihiro;Wood, Thomas K.
此前，我们使用杨树模型确定了未鉴定的铜绿假单胞菌PAO1膜蛋白PA2663是一个毒力因子；PA2663在杨树根际诱导，失活后，它导致生物膜形成减少20倍(Attila等人，Microb Biotechnol，2008)。在此，我们通过补充PA2663反式突变恢复野生型表型，证实了PA2663与生物膜形成有关，并通过全转录组和表型研究探讨了其影响生物膜形成的遗传基础。通过插入转座子使PA2663失活后，编码富含半乳糖和甘露糖的胞外多糖的PSL操纵子被高度抑制(经RT-PCR验证)。PA2663的失活还抑制了13个吡喃甲苷基因的表达，从而消除了铜绿假单胞菌毒力因子吡喃甲苷的产生。PA2663的失活还影响到其他与群体感应相关的表型，因为它抑制了假单胞菌喹诺酮信号(PQS)基因，该基因取消了PQS的产生，并抑制了lasB，后者使弹性蛋白酶活性降低了7倍。也诱导了运动性和附着性基因(PA0499、PA0993、PA2130和PA4549)和小分子运输基因(PA0326、PA1541、PA1632、PA1971、PA2214、PA2215、PA2678和PA3407)。表型阵列还显示，PA2663抑制D-葡萄糖酸、D-甘露醇和N-邻苯二甲酰-L-谷氨酸的生长。因此，PA2663基因产物通过增加PSL操纵子衍生的胞外多糖来增加生物膜的形成，并增加吡喃佛丁的合成、PQS的产生和弹性淀粉酶的活性，同时减少集群和游泳运动。我们推测，PA2663作为一种新型的膜传感器可以实现这些功能。
Previously, we identified the uncharacterized predicted membrane protein PA2663 of Pseudomonas aeruginosa PAO1 as a virulence factor using a poplar tree model; PA2663 was induced in the poplar rhizosphere and, upon inactivation, it caused 20-fold lower biofilm formation (Attila et al., Microb Biotechnol, 2008). Here, we confirmed that PA2663 is related to biofilm formation by restoring the wild-type phenotype by complementing the PA2663 mutation in trans and investigated the genetic basis of its influence on biofilm formation through whole-transcriptome and -phenotype studies. Upon inactivating PA2663 by transposon insertion, the psl operon that encodes a galactose- and mannose-rich exopolysaccharide was highly repressed (verified by RT-PCR). The inactivation of PA2663 also repressed 13 pyoverdine genes, which eliminated the production of the virulence factor pyoverdine in P. aeruginosa. The inactivation of PA2663 also affected other quorum-sensing-related phenotypes in that it repressed the Pseudomonas quinolone signal (PQS) genes, which abolished PQS production, and repressed lasB, which decreased elastase activity sevenfold. Genes were also induced for motility and attachment (PA0499, PA0993, PA2130, and PA4549) and for small molecule transport (PA0326, PA1541, PA1632, PA1971, PA2214, PA2215, PA2678, and PA3407). Phenotype arrays also showed that PA2663 represses growth on D-gluconic acid, D-mannitol, and N-phthaloyl-L-glutamic acid. Hence, the PA2663 gene product increases biofilm formation by increasing the psl-operon-derived exopolysaccharides and increases pyoverdine synthesis, PQS production, and elastase activity while reducing swarming and swimming motility. We speculate that PA2663 performs these myriad functions as a novel membrane sensor.