title: The ClpP protease homologue is required for the transmission traits and cell division of the pathogen Legionella pneumophila.
abstract: BACKGROUND
  Legionella pneumophila, the intracellular bacterial pathogen that causes Legionnaires' disease, exhibit characteristic transmission traits such as elevated stress tolerance, shortened length and virulence during the transition from the replication phase to the transmission phase. ClpP, the catalytic core of the Clp proteolytic complex, is widely involved in many cellular processes via the regulation of intracellular protein quality.
  
  
  RESULTS
  In this study, we showed that ClpP was required for optimal growth of L. pneumophila at high temperatures and under several other stress conditions. We also observed that cells devoid of clpP exhibited cell elongation, incomplete cell division and compromised colony formation. Furthermore, we found that the clpP-deleted mutant was more resistant to sodium stress and failed to proliferate in the amoebae host Acanthamoeba castellanii.
  
  
  CONCLUSIONS
  The data present in this study illustrate that the ClpP protease homologue plays an important role in the expression of transmission traits and cell division of L. pneumophila, and further suggest a putative role of ClpP in virulence regulation.
authors.affiliation: Department of Biochemistry, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China.
authors.forename: Xiang-hui
authors.initials: XH
authors.lastname: Li
authors.forename: Yong-lun
authors.initials: YL
authors.lastname: Zeng
authors.forename: Ye
authors.initials: Y
authors.lastname: Gao
authors.forename: Xiao-cong
authors.initials: XC
authors.lastname: Zheng
authors.forename: Qin-fen
authors.initials: QF
authors.lastname: Zhang
authors.forename: Shi-ning
authors.initials: SN
authors.lastname: Zhou
authors.forename: Yong-jun
authors.initials: YJ
authors.lastname: Lu
mesh_terms: D048248:Acanthamoeba castellanii / Q000382:microbiology; D000595:Amino Acid Sequence; D002455:Cell Division / Q000235:genetics; D049071:Endopeptidase Clp / Q000235:genetics / Q000502:physiology*; D006358:Hot Temperature; D016952:Legionella pneumophila / Q000166:cytology / Q000235:genetics / Q000472:pathogenicity / Q000502:physiology*; D008969:Molecular Sequence Data; D009154:Mutation; D016415:Sequence Alignment; D012965:Sodium Chloride / Q000494:pharmacology; D013312:Stress, Physiological / Q000187:drug effects / Q000235:genetics
chemical_list: D012965:Sodium Chloride; D049071:Endopeptidase Clp