title: Helicobacter pylori HP0425 Targets the Nucleus with DNase I-Like Activity.
abstract: OBJECTIVE
  Nuclear targeting of bacterial proteins has a significant impact on host cell pathology. Helicobacter pylori have many nuclear targeting proteins that translocate into the nucleus of host cells. H. pylori HP0425, annotated as hypothetical, has a nuclear localization signal (NLS) sequence, but its function has not been demonstrated. The aim of this experiment was to address the nuclear translocation of HP0425 and determine the effect of HP0425 pathology on host cells.
  
  
  METHODS
  To investigate the nuclear localization of HP0425, it was expressed in AGS and MKN-1 cells as a GFP fusion protein (pEGFP-HP0425), and its localization was analyzed by confocal microscopy. Recombinant HP0425 (rHP0425) protein was overproduced as a GST fusion protein in Escherichia coli and purified by glutathione-affinity column chromatography. Purified rHP0425 was examined for cytotoxicity and DNase activity.
  
  
  RESULTS
  The pEGFP-HP0425 fluorescence was expressed in the nucleus and cytosol fraction of cells, while it was localized in the cytoplasm in the negative control. This protein exhibited DNase activity under various conditions, with the highest DNase activity in the presence of manganese. In addition, the rHP0425 protein efficiently decreased cell viability in a concentration-dependent manner.
  
  
  CONCLUSIONS
  These results suggest that HP0425 carrying a nuclear localization signal sequence translocates into the nucleus of host cells and degrades genomic DNA by DNase I-like enzymatic activity, which is a new pathogenic strategy of H. pylori in the host.
authors.affiliation: Department of Microbiology, Gyeongsang National University School of Medicine, Jinju, Korea.
authors.forename: Jung-Min
authors.initials: JM
authors.lastname: Kim
authors.affiliation: Department of Microbiology, Gyeongsang National University School of Medicine, Jinju, Korea.
authors.forename: Min-Ho
authors.initials: MH
authors.lastname: Choe
authors.affiliation: Department of Microbiology, Gyeongsang National University School of Medicine, Jinju, Korea.
authors.forename: Killivalavan
authors.initials: K
authors.lastname: Asaithambi
authors.affiliation: Department of Microbiology, Gyeongsang National University School of Medicine, Jinju, Korea.
authors.forename: Jae-Young
authors.initials: JY
authors.lastname: Song
authors.affiliation: Department of Life Science and Biotechnology, College of Natural Sciences, Soonchunhyang University, Asan, Korea.
authors.forename: Yong Seok
authors.initials: YS
authors.lastname: Lee
authors.affiliation: Department of Microbiology, Kyungpook National University School of Medicine, Daegu, Korea.
authors.forename: Je Chul
authors.initials: JC
authors.lastname: Lee
authors.affiliation: Department of Pediatrics, Gyeongsang Institute of Health Science, Gyeongsang National University School of Medicine, Jinju, Korea.
authors.forename: Ji-Hyun
authors.initials: JH
authors.lastname: Seo
authors.affiliation: Department of Microbiology, Gyeongsang National University School of Medicine, Jinju, Korea.|Research Institute of Life Science, Gyeongsang National University, Jinju, Korea.
authors.forename: Hyung-Lyun
authors.initials: HL
authors.lastname: Kang
authors.affiliation: Department of Microbiology, Gyeongsang National University School of Medicine, Jinju, Korea.|Research Institute of Life Science, Gyeongsang National University, Jinju, Korea.
authors.forename: Kon Ho
authors.initials: KH
authors.lastname: Lee
authors.affiliation: Department of Microbiology, Gyeongsang National University School of Medicine, Jinju, Korea.|Research Institute of Life Science, Gyeongsang National University, Jinju, Korea.
authors.forename: Woo-Kon
authors.initials: WK
authors.lastname: Lee
authors.affiliation: Department of Microbiology, Gyeongsang National University School of Medicine, Jinju, Korea.|Research Institute of Life Science, Gyeongsang National University, Jinju, Korea.
authors.forename: Myung-Je
authors.initials: MJ
authors.lastname: Cho
authors.affiliation: Department of Microbiology, Gyeongsang National University School of Medicine, Jinju, Korea.|Research Institute of Life Science, Gyeongsang National University, Jinju, Korea.
authors.forename: Kwang-Ho
authors.initials: KH
authors.lastname: Rhee
authors.affiliation: Department of Pediatrics, Gyeongsang Institute of Health Science, Gyeongsang National University School of Medicine, Jinju, Korea.
authors.forename: Hee-Shang
authors.initials: HS
authors.lastname: Youn
authors.affiliation: Department of Microbiology, Gyeongsang National University School of Medicine, Jinju, Korea.|Research Institute of Life Science, Gyeongsang National University, Jinju, Korea.
authors.forename: Seung-Chul
authors.initials: SC
authors.lastname: Baik
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D002460:Cell Line; D002467:Cell Nucleus / Q000201:enzymology / Q000382:microbiology*; D003593:Cytoplasm / Q000378:metabolism; D003850:Deoxyribonuclease I / Q000235:genetics / Q000378:metabolism*; D049452:Green Fluorescent Proteins; D016481:Helicobacter Infections / Q000382:microbiology*; D016480:Helicobacter pylori / Q000201:enzymology / Q000472:pathogenicity*; D006801:Humans; D018613:Microscopy, Confocal; D019913:Nuclear Localization Signals; D021381:Protein Transport; D011993:Recombinant Fusion Proteins
chemical_list: D001426:Bacterial Proteins; D019913:Nuclear Localization Signals; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins; D003850:Deoxyribonuclease I
keywords: DNase I-like activity; H. pylori; HP0425; NLS sequence