title: Anaplasma phagocytophilum AnkA binds to granulocyte DNA and nuclear proteins.
abstract: Human granulocytic anaplasmosis (HGA) is caused by the obligate intracellular bacterium Anaplasma phagocytophilum. The bacterium infects, survives, propagates in, and alters neutrophil phenotype, indicating unique survival mechanisms. AnkA is the only known A. phagocytophilum component that gains access beyond neutrophil vacuoles and is transported to the infected host cell nucleus. The ability of native and recombinant AnkA to bind DNA and nuclear proteins from host HL-60 cells was assessed by the use of immunoprecipitation after cis-diamminedichloroplatinum (cis-DDP) DNA-protein crosslinking, by probing uninfected HL-60 cell nuclear lysates for AnkA binding, and by recovery and sequence analysis of immunoprecipitated DNA. AnkA binds HL-60 cell DNA as well as nuclear proteins of approximately 86, 53 and 25 kDa, whereas recombinant A. phagocytophilum Msp2 or control proteins do not. DNA immunoprecipitation reveals AnkA binding to a variety of target genes in the human genome, including genes that encode proteins with ATPase, tyrosine phosphatase and NADH dehydrogenase-like functions. These data indicate that AnkA could exert some effect on cells through binding to protein:DNA complexes in neutrophil nuclei. Whether AnkA binding leads to neutrophil functional alterations, and how such alterations might occur will depend upon definitive identification of binding partners and associated metabolic and biochemical pathways.
authors.affiliation: Division of Medical Microbiology, Department of Pathology, The Johns Hopkins University School of Medicine, Ross Research Building, 720 Rutland Avenue, Baltimore, Maryland, USA.
authors.forename: Jinho
authors.initials: J
authors.lastname: Park
authors.forename: Kee Jun
authors.initials: KJ
authors.lastname: Kim
authors.forename: Kyoung-seong
authors.initials: KS
authors.lastname: Choi
authors.forename: Dennis J
authors.initials: DJ
authors.lastname: Grab
authors.forename: J Stephen
authors.initials: JS
authors.lastname: Dumler
mesh_terms: D000251:Adenosine Triphosphatases / Q000235:genetics; D041081:Anaplasma phagocytophilum / Q000378:metabolism*; D000942:Antigens, Bacterial / Q000378:metabolism*; D001426:Bacterial Proteins / Q000378:metabolism*; D002467:Cell Nucleus / Q000378:metabolism / Q000382:microbiology; D004247:DNA / Q000032:analysis / Q000378:metabolism*; D006098:Granulocytes / Q000382:microbiology*; D018922:HL-60 Cells; D006801:Humans; D008970:Molecular Weight; D009245:NADH Dehydrogenase / Q000235:genetics; D009687:Nuclear Proteins / Q000378:metabolism*; D011233:Precipitin Tests; D017027:Protein Tyrosine Phosphatases / Q000235:genetics
chemical_list: D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D009687:Nuclear Proteins; C413306:ank protein, Ehrlichia; D004247:DNA; D009245:NADH Dehydrogenase; D017027:Protein Tyrosine Phosphatases; D000251:Adenosine Triphosphatases