title: [Comparative proteomics analysis of extracellular proteins from Listeria monocytogenes and its isogenic prfA deletion mutant].
abstract: OBJECTIVE
  Positive regulatory factor A (PrfA) protein plays a key role in the pathogenicity of Listeria monocytogenes by regulating the expression of virulence genes. We studied the regulation functions of PrfA and its role in Listeria monocytogenes (Lm) virulence.
  
  
  METHODS
  Extracellular proteins were obtained from the supernatants of parental strain LM4 and mutant strain LM4deltaprfA cultured in minimal medium. We used two-dimensional gel electrophoresis and matrix associated laser dissociation/ionization time of flight mass spectrometry (MALDI- TOF-MS) to analyze the differences of secreted proteins between LM4 and LM4deltaprfA.
  
  
  RESULTS
  The electrophoresis results show that 31 different spots, 19 spots corresponding 12 proteins were identified by MALDI- TOF-MS. Some virulence related proteins were verified, such as InlC, ActA and LLO. Some new proteins that are regulated by PrfA include D-alanyl-D-alanine carboxypeptidase, dipeptide Glycine and Trytophan (GW) repeat-containing surface protein, transcriptional regulator and some hypothetical proteins with unknown functions. Real-time quantitative PCR was conducted to verify the proteomics results. The mRNA expression level of hly, actA and inlC gene was significantly reduced, and that of D-alanyl-D-alanine carboxypeptidase and GW repeat-containing surface protein's synthesis also had a reduction in LM4deltaprfA strain.
  
  
  CONCLUSIONS
  PrfA plays key roles on the regulation of genes in LIPI- I and LIPI- II.
authors.affiliation: Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou 225009, China. yylan@yzu.edu.cn
authors.forename: Yuelan
authors.initials: Y
authors.lastname: Yin
authors.forename: Chunguang
authors.initials: C
authors.lastname: Bai
authors.forename: Guoliang
authors.initials: G
authors.lastname: Wang
authors.forename: Yanyan
authors.initials: Y
authors.lastname: Jia
authors.forename: Jin
authors.initials: J
authors.lastname: Qu
authors.forename: Hong
authors.initials: H
authors.lastname: Fu
authors.forename: Yunfei
authors.initials: Y
authors.lastname: Gao
authors.forename: Xin'an
authors.initials: X
authors.lastname: Jiao
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D008089:Listeria monocytogenes / Q000235:genetics* / Q000378:metabolism*; D009154:Mutation; D010454:Peptide Termination Factors / Q000235:genetics* / Q000378:metabolism*; D020543:Proteome / Q000235:genetics* / Q000378:metabolism*; D040901:Proteomics / Q000379:methods
chemical_list: D001426:Bacterial Proteins; D010454:Peptide Termination Factors; C545356:PrfA protein, Listeria monocytogenes; D020543:Proteome