RRC ID 29057
Author Otto GP, Wu MY, Clarke M, Lu H, Anderson OR, Hilbi H, Shuman HA, Kessin RH.
Title Macroautophagy is dispensable for intracellular replication of Legionella pneumophila in Dictyostelium discoideum.
Journal Mol Microbiol
Abstract The Gram-negative bacterium Legionella pneumophila is a facultative intracellular pathogen of free-living amoebae and mammalian phagocytes. L. pneumophila is engulfed in phagosomes that initially avoid fusion with lysosomes. The phagosome associates with endoplasmic reticulum (ER) and mitochondria and eventually resembles ER. The morphological similarity of the replication vacuole to autophagosomes, and enhanced bacterial replication in response to macroautophagy-inducing starvation, led to the hypothesis that L. pneumophila infection requires macroautophagy. As L. pneumophila replicates in Dictyostelium discoideum, and macroautophagy genes have been identified and mutated in D. discoideum, we have taken a genetic and cell biological approach to evaluate the relationship between host macroautophagy and intracellular replication of L. pneumophila. Mutation of the apg1, apg5, apg6, apg7 and apg8 genes produced typical macroautophagy defects, including reduced bulk protein degradation and cell viability during starvation. We show that L. pneumophila replicates normally in D. discoideum macroautophagy mutants and produces replication vacuoles that are morphologically indistinguishable from those in wild-type D. discoideum. Furthermore, a green fluorescent protein (GFP)-tagged marker of autophagosomes, Apg8, does not systematically co-localize with DsRed-labelled L. pneumophila. We conclude that macroautophagy is dispensable for L. pneumophila intracellular replication in D. discoideum.
Volume 51(1)
Pages 63-72
Published 2004-1-1
DOI 10.1046/j.1365-2958.2003.03826.x
PII 3826
PMID 14651611
MeSH Animals Autophagy / physiology* Cell Division Dictyostelium / microbiology* Dictyostelium / ultrastructure Endoplasmic Reticulum / microbiology Kinetics Legionella pneumophila / cytology Legionella pneumophila / pathogenicity* Microscopy, Fluorescence Vacuoles / microbiology Vacuoles / ultrastructure
IF 3.418
Times Cited 99
Cellular slime molds S00447 S00449