title: Nuclear translocation and DNAse I-like enzymatic activity of Acinetobacter baumannii outer membrane protein A.
abstract: Acinetobacter baumannii outer membrane protein A (AbOmpA) is a potential virulence factor that induces host cell death. Based on previous findings that AbOmpA translocated into the nuclei of host cells, the cell-death mechanism of AbOmpA through the nuclear targeting was investigated. Acinetobacter baumannii secreted AbOmpA in in vitro culture. The recombinant AbOmpA (rAbOmpA) was internalized by the host cells. The intracellular rAbOmpA was degraded into several forms of subfragments in the cytosol and then two subfragments of rAbOmpA translocated into the nuclei. The rAbOmpA exhibited the divalent cation-dependent endonuclease activity. In an in vivo assay with microinjection of rAbOmpA into the nucleus of fertilized Xenopus laevis eggs, rAbOmpA degraded chromosomal DNA with the characteristic DNA ladders and induced degeneration of the embryos. These results suggest that AbOmpA translocates into the nuclei of host cells and degrades chromosomal DNA by DNAse I-like enzymatic activity, which is a new pathogenic strategy of A. baumannii.
authors.forename: Chul Hee
authors.initials: CH
authors.lastname: Choi
authors.forename: Sung Hee
authors.initials: SH
authors.lastname: Hyun
authors.forename: Jungmin
authors.initials: J
authors.lastname: Kim
authors.forename: Yoo Chul
authors.initials: YC
authors.lastname: Lee
authors.forename: Sung Yong
authors.initials: SY
authors.lastname: Seol
authors.forename: Dong Taek
authors.initials: DT
authors.lastname: Cho
authors.forename: Je Chul
authors.initials: JC
authors.lastname: Lee
mesh_terms: D000151:Acinetobacter Infections / Q000378:metabolism / Q000382:microbiology*; D040981:Acinetobacter baumannii / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D000818:Animals; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D019556:COS Cells; D002460:Cell Line; D002467:Cell Nucleus / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D002522:Chlorocebus aethiops; D004247:DNA / Q000378:metabolism; D003850:Deoxyribonuclease I / Q000235:genetics / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D008845:Microinjections; D021381:Protein Transport; D014982:Xenopus laevis
chemical_list: D001425:Bacterial Outer Membrane Proteins; C078167:OMPA outer membrane proteins; D004247:DNA; D003850:Deoxyribonuclease I