title: Molecular characterization of the Dot/Icm-translocated AnkH and AnkJ eukaryotic-like effectors of Legionella pneumophila.
abstract: Although most Dot/Icm-translocated effectors of Legionella pneumophila are not required for intracellular proliferation, the eukaryotic-like ankyrin effectors, AnkH and AnkJ are required for intracellular proliferation. In this report, we show that the IcmSW chaperones are essential for translocation of AnkJ but not AnkH. The 10 C-terminal residues and the ANK domains of AnkH and AnkJ are required for translocation. Our data indicate that the two ANK domains of AnkH are critical domains required for the function of the effector in intracellular replication of L. pneumophila. The ankH and ankJ mutants are severely defective in intrapulmonary proliferation in mice. Expression of AnkH and AnkJ fusions within HEK293 cells show a punctuate distribution in the cytosol but no association with endocytic vesicles, the Golgi apparatus or the endoplasmic reticulum. Interestingly, the defect in intracellular proliferation of the ankH or ankJ mutants is rescued in HEK293 cells expressing the respective protein. We conclude that AnkH and AnkJ are effectors translocated by the Dot/Icm system by distinct mechanisms and modulate distinct cytosolic processes in the host cell.
authors.affiliation: Department of Microbiology and Immunology, Room MS-410, College of Medicine, University of Louisville, Louisville, Kentucky 40292, USA.
authors.forename: Fabien
authors.initials: F
authors.lastname: Habyarimana
authors.forename: Chris T
authors.initials: CT
authors.lastname: Price
authors.forename: Marina
authors.initials: M
authors.lastname: Santic
authors.forename: Souhaila
authors.initials: S
authors.lastname: Al-Khodor
authors.forename: Yousef Abu
authors.initials: YA
authors.lastname: Kwaik
mesh_terms: D000818:Animals; D017487:Ankyrins / Q000235:genetics / Q000502:physiology*; D002460:Cell Line; D015169:Colony Count, Microbial; D003593:Cytoplasm / Q000737:chemistry; D004195:Disease Models, Animal; D006801:Humans; D016952:Legionella pneumophila / Q000472:pathogenicity*; D007877:Legionnaires' Disease / Q000382:microbiology; D051379:Mice; D018832:Molecular Chaperones / Q000235:genetics / Q000378:metabolism*; D054730:Protein Interaction Domains and Motifs; D025941:Protein Interaction Mapping; D016019:Survival Analysis; D037521:Virulence Factors / Q000235:genetics / Q000502:physiology*
chemical_list: D017487:Ankyrins; C503175:IcmS protein, Legionella pneumophila; D018832:Molecular Chaperones; D037521:Virulence Factors