LidA, a translocated substrate of the Legionella pneumophila type IV secretion system, interferes with the early secretory pathway.
Legionella pneumophila uses a type IV secretion system to deliver effector molecules into the host cell and establish its replication vacuole. In this study, we investigated the role of LidA, a translocated substrate associated with the surface of the L. pneumophila-containing vacuole. LidA is secreted into the host cell throughout the replication cycle of the bacteria and associates with compartments of the early secretory pathway. When overexpressed in mammalian cells or yeast, LidA interferes with the early secretory pathway, probably via a domain predicted to be rich in coiled-coil structure. Finally, during intracellular replication, the replication vacuoles are in close contact with the endoplasmic reticulum-Golgi intermediate compartment and the Golgi apparatus, suggesting a positive correlation between intracellular growth and association of the vacuole with compartments of the early secretory pathway. We propose that LidA is involved in the recruitment of early secretory vesicles to the L. pneumophila-containing vacuole and that the vacuole associates with the secretory pathway to facilitate this process.
Derré
Isabelle
I
Department of Molecular Biology and Microbiology, Tufts University School of Medicine, 150 Harrison Ave., Boston, Massachusetts 02111, USA.
Isberg
Ralph R
RR
D000818:Animals; D001426:Bacterial Proteins / Q000502:physiology*; D019556:COS Cells; D004721:Endoplasmic Reticulum / Q000382:microbiology; D006056:Golgi Apparatus / Q000382:microbiology; D006801:Humans; D016952:Legionella pneumophila / Q000254:growth & development / Q000378:metabolism*; D021381:Protein Transport; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D020298:U937 Cells; D014617:Vacuoles / Q000382:microbiology*
D001426:Bacterial Proteins