title: A bacterial guanine nucleotide exchange factor activates ARF on Legionella phagosomes.
abstract: The intracellular pathogen Legionella pneumophila subverts vesicle traffic in eukaryotic host cells to create a vacuole that supports replication. The dot/icm genes encode a protein secretion apparatus that L. pneumophila require for biogenesis of this vacuole. Here we show that L. pneumophila produce a protein called RalF that functions as an exchange factor for the ADP ribosylation factor (ARF) family of guanosine triphosphatases (GTPases). The RalF protein is required for the localization of ARF on phagosomes containing L. pneumophila. Translocation of RalF protein through the phagosomal membrane is a dot/icm-dependent process. Thus, RalF is a substrate of the Dot/Icm secretion apparatus.
authors.affiliation: Section of Microbial Pathogenesis, Yale University School of Medicine, Boyer Center for Molecular Medicine, 295 Congress Avenue, New Haven, CT 06536, USA.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Nagai
authors.forename: Jonathan C
authors.initials: JC
authors.lastname: Kagan
authors.forename: Xinjun
authors.initials: X
authors.lastname: Zhu
authors.forename: Richard A
authors.initials: RA
authors.lastname: Kahn
authors.forename: Craig R
authors.initials: CR
authors.lastname: Roy
mesh_terms: D020823:ADP-Ribosylation Factor 1 / Q000235:genetics / Q000378:metabolism*; D020727:ADP-Ribosylation Factors / Q000378:metabolism; D000048:Acanthamoeba / Q000382:microbiology; D000595:Amino Acid Sequence; D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D002460:Cell Line; D005798:Genes, Bacterial; D020662:Guanine Nucleotide Exchange Factors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D007875:Legionella / Q000235:genetics; D016952:Legionella pneumophila / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D008264:Macrophages / Q000382:microbiology; D051379:Mice; D008805:Mice, Inbred A; D008969:Molecular Sequence Data; D010588:Phagosomes / Q000378:metabolism* / Q000382:microbiology*; D017434:Protein Structure, Tertiary; D021381:Protein Transport; D012329:RNA, Bacterial / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D017386:Sequence Homology, Amino Acid
chemical_list: D001426:Bacterial Proteins; D002352:Carrier Proteins; D020662:Guanine Nucleotide Exchange Factors; D012329:RNA, Bacterial; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; D020823:ADP-Ribosylation Factor 1; D020727:ADP-Ribosylation Factors