title: [Differential expression of two phenazine-producing loci mediated by deficiency of the global regulator rsmA in Psedomonas aeruginosa PAO1].
abstract: In many Pseudomonas, RsmA mediates the production of a set of secondary metabolites or virulence factors.
  
  
  OBJECTIVE
  Our aim is to evaluate the function and regulation of the rsmA gene on two phenazine-producing operons in Pseudomonas aeruginosa PAO1.
  
  
  METHODS
  We first cloned the upstream and downstream fragments of the rsmA gene from the chromosomal DNA. With the insertion of gentamycin resistance cassette (aacC1), the deletion mutant PA-RG was created and verified with PCR. To complement and overexpress the rsmA gene, pME10R and pME32R were also constructed. By constructing the translational fusion plasmids phz1'-'lacZ pMEZ1 and phz2'-'lacZ pMEZ2, we introduced them into the wild type strain PAO1 and the mutant PA-RG, respectively. Activities of beta-galactosidase were determined with Miller method.
  
  
  RESULTS
  In glycerol-alanine medium, overexpression of the rsmA gene results in dramatical decrease of pyocyanin production in PA-RG and PAO1 strain. In addition, beta-galactosidase activity of phz1'-'lacZ in the mutant PA-RG was much higher than that in the wild type strain. However, beta-galactosidase activity of phz2'-'lacZ in the wild type strain was 2fold more than that in the mutant PA-RG.
  
  
  CONCLUSIONS
  The regulation mediated by RsmA on two phenazine loci is specific and differential.
authors: School of Life Sciences, Ludong University, Yantai 264025, China. cuiqinna@163.com
authors: Qinna
authors: Q
authors: Cui
authors: Fang
authors: F
authors: Li
authors: Weiyue
authors: W
authors: Xing
authors: Xiaoyan
authors: X
authors: Chi
authors: Zhibin
authors: Z
authors: Feng
authors: Yanhua
authors: Y
authors: Wang
authors: Yihe
authors: Y
authors: Ge
authors: Linde
authors: L
authors: Liu
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D015536:Down-Regulation; D015964:Gene Expression Regulation, Bacterial; D005809:Genes, Regulator; D009876:Operon; D010619:Phenazines / Q000378:metabolism*; D011550:Pseudomonas aeruginosa / Q000235:genetics / Q000378:metabolism*; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D010619:Phenazines; D012097:Repressor Proteins