Nuclear translocation and DNAse I-like enzymatic activity of Acinetobacter baumannii outer membrane protein A.
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.
Choi
Chul Hee
CH
Hyun
Sung Hee
SH
Kim
Jungmin
J
Lee
Yoo Chul
YC
Seol
Sung Yong
SY
Cho
Dong Taek
DT
Lee
Je Chul
JC
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
D001425:Bacterial Outer Membrane Proteins; C078167:OMPA outer membrane proteins; D004247:DNA; D003850:Deoxyribonuclease I