title: Photobacterium damselae subsp. piscicida responds to antimicrobial peptides through phage-shock-protein A (PspA)-related extracytoplasmic stress response system.
abstract: OBJECTIVE
  To investigate whether Photobacterium damselae subsp. piscicida (Phdp) can sense and directly respond to the presence of cationic antimicrobial peptides (AMPs).
  
  
  RESULTS
  We performed proteomic methodologies to investigate the responsive proteins of Phdp on exposure to AMP Q6. Proteins significantly altered were analysed by two-dimensional gel electrophoresis (2-DE) and LC-ESI-Q-TOF MS/MS, thus resulting in five outer membrane proteins (OMPs), seven inner membrane proteins (IMPs) and 17 cytoplasmic proteins (CPs) identified. Quantitative real-time PCR was also applied to monitor the mRNA expression level of these target proteins.
  
  
  CONCLUSIONS
  COG analysis revealed that upon exposure to AMP Q6, the majority of the upregulated proteins were involved in signal transduction mechanism, carbohydrate transport and metabolism, post-translational modification, protein turnover and chaperones, while the downregulated proteins were mainly related to energy production and conversion. Among them, phage-shock-protein A (PspA)-related stress response system was considered to play a crucial role.
  
  
  CONCLUSIONS
  To the best of our knowledge, this is the first report elucidating Phdp AMP-response mechanism using proteomics approach. AMP-responsive proteins identified in this study could serve as attractive targets for developing more effective antimicrobial agents against Phdp and other marine bacterial pathogens.
authors.affiliation: Department of Biotechnology and Animal Science, National Ilan University, Ilan, Taiwan.
authors.forename: W-C
authors.initials: WC
authors.lastname: Tsai
authors.forename: T-Y
authors.initials: TY
authors.lastname: Kuo
authors.forename: C-Y
authors.initials: CY
authors.lastname: Lin
authors.forename: J-C
authors.initials: JC
authors.lastname: Lin
authors.forename: W-J
authors.initials: WJ
authors.lastname: Chen
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D023181:Antimicrobial Cationic Peptides / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000378:metabolism*; D006360:Heat-Shock Proteins / Q000378:metabolism*; D008565:Membrane Proteins / Q000378:metabolism; D010776:Photobacterium / Q000187:drug effects* / Q000378:metabolism / Q000648:ultrastructure; D040901:Proteomics; D013312:Stress, Physiological
chemical_list: D000900:Anti-Bacterial Agents; D023181:Antimicrobial Cationic Peptides; D001426:Bacterial Proteins; D006360:Heat-Shock Proteins; D008565:Membrane Proteins; C069816:phage shock protein, Bacteria
keywords: Photobacterium damselae subsp. piscicida; antimicrobial peptides; phage-shock-protein A (PspA); proteomics; stress response