title: Legionella metaeffector exploits host proteasome to temporally regulate cognate effector.
abstract: Pathogen-associated secretion systems translocate numerous effector proteins into eukaryotic host cells to coordinate cellular processes important for infection. Spatiotemporal regulation is therefore important for modulating distinct activities of effectors at different stages of infection. Here we provide the first evidence of "metaeffector," a designation for an effector protein that regulates the function of another effector within the host cell. Legionella LubX protein functions as an E3 ubiquitin ligase that hijacks the host proteasome to specifically target the bacterial effector protein SidH for degradation. Delayed delivery of LubX to the host cytoplasm leads to the shutdown of SidH within the host cells at later stages of infection. This demonstrates a sophisticated level of coevolution between eukaryotic cells and L. pneumophila involving an effector that functions as a key regulator to temporally coordinate the function of a cognate effector protein.
authors.affiliation: Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, Japan.
authors.forename: Tomoko
authors.initials: T
authors.lastname: Kubori
authors.forename: Naoaki
authors.initials: N
authors.lastname: Shinzawa
authors.forename: Hirotaka
authors.initials: H
authors.lastname: Kanuka
authors.forename: Hiroki
authors.initials: H
authors.lastname: Nagai
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000378:metabolism / Q000502:physiology; D002460:Cell Line; D004331:Drosophila melanogaster / Q000382:microbiology; D054884:Host-Pathogen Interactions; D007875:Legionella / Q000472:pathogenicity / Q000502:physiology*; D016952:Legionella pneumophila; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism*; D013997:Time Factors; D044767:Ubiquitin-Protein Ligases
chemical_list: D001426:Bacterial Proteins; D044767:Ubiquitin-Protein Ligases; D046988:Proteasome Endopeptidase Complex