Effector Protein Translocation by the Coxiella burnetii Dot/Icm Type IV Secretion System Requires Endocytic Maturation of the Pathogen-Occupied Vacuole

• DOI: 10.1371/journal.pone.0054566
• Publication Date: 2013-01-17T22:10:19Z
• Authors: Hayley J. Newton; Justin A. McDonough; Craig R. Roy
• Keywords: Coxiella burnetii; Transport protein

The human pathogen Coxiella burnetii encodes a type IV secretion system called Dot/Icm that is essential for intracellular replication. delivers bacterial effector proteins into the host cytosol during infection. delivered by C. are predicted to have important functions infection, but when these needed infection has not been clearly defined. Here, we use reporter consisting of fusion β-lactamase enzyme (BlaM) fused study protein translocation system. Translocation BlaM CBU0077, CBU1823 and CBU1524 was detected until 8-hours after HeLa cells, which permissive required acidification Coxiella-containing vacuole. Silencing genes encoding membrane transport regulators Rab5 or Rab7 interfered with translocation, indicates effectors translocated bacteria traffic late endocytic compartment in cell. Similar requirements were discerned bone marrow macrophages derived from C57BL/6 mice, primary cells restrict replication burnetii. In addition requiring maturation vacuole Dot/Icm-mediated effectors, transcription this process. Thus, occurs CCV specialized organelle compartment. This creation replicates represents two-stage process mediated initially factors regulate then establish residency lysosome-derived organelle.