Role of RsmA in the regulation of swarming motility and virulence factor expression in Proteus mirabilis
Role of RsmA in the regulation of swarming motility and virulence factor expression in Proteus mirabilis
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DOI：
10.1099/jmm.0.05024-0
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发表时间：
2003-01-01
影响因子：
3
通讯作者：
Wang, WB
中科院分区：
文献类型：
--
作者：
Liaw, SJ;Lai, HC;Wang, WB
奇异变形杆菌的集群包括将典型的短营养杆分化为丝状的高鞭毛集群细胞，这些细胞经历了快速和协调的种群跨越表面的迁移周期，并表现出高水平的毒力基因表达。RSMA(次级代谢产物抑制物)和CSRA是其在大肠杆菌中的同源物，它们控制着许多表型特征，如欧文氏菌的运动和致病，大肠杆菌的糖原生物合成，细胞大小和生物膜的形成，以及粘质沙雷氏菌的成群运动。为了研究RSMA基因在奇异变形杆菌中的作用，克隆了奇异变形杆菌RSMA基因(以下简称RSMA(Pm))。RSMA(Pm)与大肠杆菌CSRA和从胡萝卜欧文氏菌亚种中克隆的RSMA具有较高的序列相似性。胡萝卜素、粘质沙雷氏菌、流感嗜血杆菌和枯草芽孢杆菌，并可补充大肠杆菌CSRA突变体的糖原合成。从其天然启动子表达的携带rsmApm的低拷贝数质粒可抑制奇异变形杆菌的群体运动和毒力因子的表达。信使核糖核酸稳定性分析表明，RSMA(Pm)通过促进信使核糖核酸降解抑制毒力因子表达。粘质沙雷氏菌和胡萝卜欧文氏亚种RSMA同源物的克隆。胡萝卜素还能抑制奇异变形杆菌的群体和毒力因子的表达。
Swarming by Proteus mirabilis involves differentiation of typical short vegetative rods into filamentous hyper-flagellated swarm cells that undergo cycles of rapid and co-ordinated population migration across surfaces and exhibit high levels of virulence gene expression. RsmA (repressor of secondary metabolites) and CsrA, its homologue in Escherichia coli, control many phenotypic traits, such as motility and pathogenesis in Erwinia species, glycogen biosynthesis, cell size and biofilm formation in Escherichia coli and swarming motility in Serratia marcescens. To investigate the role of RsmA in Proteus mirabilis, the rsmA gene from Proteus mirabilis (hereafter referred to as rsmA(Pm)) was cloned. RsmA(Pm) showed high sequence similarity to Escherichia coli CsrA and RsmA cloned from Erwinia carotovora subsp. carotovora, Serratia marcescens, Haernophilus influenzae and Bacillus subtilis and could complement an Escherichia coli csrA mutant in glycogen synthesis. A low-copy-number plasmid carrying rsmApm expressed from its native promoter caused suppression of swarming motility and expression of virulence factors in Proteus mirabilis. mRNA stability assays suggested that RsmA(Pm) inhibited virulence factor expression through promoting mRNA degradation. RsmA homologues cloned from Serratia marcescens and Erwinia carotovora subsp. carotovora could also inhibit swarming and virulence factor expression in Proteus mirabilis.