ABSTRACT
Intracellular bacterial pathogens divert multiple cellular pathways to establish their niche and persist inside their host. Coxiella burnetii, the causative agent of Q fever, secretes bacterial effector proteins via its Type 4 secretion system to generate a Coxiella-containing vacuole (CCV). Manipulation of lipid and protein trafficking by these effectors is essential for bacterial replication and virulence. Here, we have characterized the lipid composition of CCVs and found that the effector Vice interacts with phosphoinositides and membranes enriched in phosphatidylserine and lysobisphosphatidic acid. Remarkably, eukaryotic cells ectopically expressing Vice present compartments that resemble early CCVs in both morphology and composition. We found that the biogenesis of these compartments relies on the double function of Vice. The effector protein initially localizes at the plasma membrane of eukaryotic cells where it triggers the internalization of large vacuoles by macropinocytosis. Then, Vice stabilizes these compartments by perturbing the ESCRT machinery. Collectively, our results reveal that Vice is an essential C. burnetii effector protein capable of hijacking two major cellular pathways to shape the bacterial replicative niche.
Subject(s)
Bacterial Proteins , Coxiella burnetii , Endosomal Sorting Complexes Required for Transport , Pinocytosis , Vacuoles , Endosomal Sorting Complexes Required for Transport/metabolism , Bacterial Proteins/metabolism , Coxiella burnetii/metabolism , Vacuoles/metabolism , Vacuoles/microbiology , Humans , HeLa Cells , Cell Membrane/metabolism , Animals , Phosphatidylinositols/metabolismABSTRACT
Title: L'actualité scientifique vue par les étudiants du Master Biologie-Santé de l'université de Montpellier. Abstract: L'unité d'enseignement « Immunopathologie ¼ qui propose les brèves présentées dans ce numéro est suivie par des étudiants de divers parcours du Master Biologie Santé de l'université de Montpellier. Ce Master rassemble des étudiants issus du domaine des sciences et technologies et de domaines de la santé. On y étudie les bases physiopathologiques des maladies immunologiques, les cibles thérapeutiques et les mécanismes d'échappement des microorganismes et des tumeurs Les articles présentés ont été choisis par les étudiants selon leur domaine de prédilection.
