Regulation of Motility in Erwinia carotovora subsp. carotovora: Quorum-Sensing Signal Controls FlhDC, the Global Regulator of Flagellar and Exoprotein Genes, by Modulating the Production of RsmA, an RNA-Binding Protein
Regulation of Motility in Erwinia carotovora subsp. carotovora: Quorum-Sensing Signal Controls FlhDC, the Global Regulator of Flagellar and Exoprotein Genes, by Modulating the Production of RsmA, an RNA-Binding Protein
复制标题
DOI：
10.1094/mpmi-01-10-0017
复制
发表时间：
2010-10-01
影响因子：
3.5
通讯作者：
Chatterjee, Arun K.
中科院分区：
文献类型：
--
作者：
Chatterjee, Asita;Cui, Yaya;Chatterjee, Arun K.
胡萝卜软腐欧文氏菌胡萝卜软腐菌在许多植物和植物器官中引起软腐（组织浸软）病。虽然果胶酶是毒力的主要决定因素，但也已鉴定出几个增强细菌毒力的辅助因子。一个这样的因素是细菌运动性。鞭毛的形成和细菌的运动在许多肠细菌中受到调节，包括大肠杆菌。胡萝卜软腐菌亚种胡萝卜软腐菌，通过FlhDC，鞭毛基因的主调节因子和FliA，鞭毛特异性α因子。我们在这里的文件，运动E。胡萝卜软腐菌亚种胡萝卜软腐菌是正调控的群体感应信号，N-酰基高丝氨酸内酯（阿勒），并负调控RsmA，转录后调节。RsmA是一种RNA结合蛋白，可引起翻译抑制并促进RNA降解。我们的数据显示RsmA负调节flhDC和fliA表达。此外，这些基因的转录本的化学稳定性在RsmA（-）突变体中比在RsmA（+）细菌中更大。这些观察结果与大肠杆菌中CsrA（= RsmA）对ADC和运动性的正调控形成对比。在不存在阿勒的情况下，胡萝卜软腐欧文氏菌（Erwinia carotovora subsp.）胡萝卜软腐菌通过激活RsmA的产生来负调节运动性和ADC和fliA的表达。在阿勒的存在下，ExpR 1/ExpR 2的调节作用被中和，导致rsmA表达水平降低和运动性增强。
Erwinia carotovora subsp. carotovora causes soft-rotting (tissue-macerating) disease in many plants and plant organs. Although pectinases are the primary determinants of virulence, several ancillary factors that augment bacterial virulence have also been identified. One such factor is bacterial motility. Flagellum formation and bacterial movement are regulated in many enterobacteria, including E. carotovora subsp. carotovora, by FlhDC, the master regulator of flagellar genes and FliA, a flagellum-specific a factor. We document here that motility of E. carotovora subsp. carotovora is positively regulated by the quorum-sensing signal, N-acylhomoserine lactone (AHL), and negatively regulated by RsmA, a post-transcriptional regulator. RsmA, an RNA-binding protein, causes translational repression and promotes RNA decay. Our data show that RsmA negatively regulates flhDC and fliA expression. Moreover, the chemical stabilities of transcripts of these genes are greater in an RsmA(-) mutant than in RsmA(+) bacteria. These observations contrast with positive regulation of ADC and motility by CsrA (= RsmA) in Escherichia coli. In the absence of AHL, the AHL receptors ExpR1/ExpR2 (= AhlR) in Erwinia carotovora subsp. carotovora negatively regulate motility and expression of ADC and fliA by activating RsmA production. In the presence of AHL, regulatory effects of ExpR1/ExpR2 are neutralized, resulting in reduced levels of rsmA expression and enhanced motility.