Journal article
Identification of Coxiella burnetii Type IV Secretion Substrates Required for Intracellular Replication and Coxiella-Containing Vacuole Formation
Journal of bacteriology, Vol.195(17), pp.3914-3924
09/2013
DOI: 10.1128/JB.00071-13
PMCID: PMC3754607
PMID: 23813730
Abstract
Coxiella burnetii
, the etiological agent of acute and chronic Q fever in humans, is a naturally intracellular pathogen that directs the formation of an acidic
Coxiella
-containing vacuole (CCV) derived from the host lysosomal network. Central to its pathogenesis is a specialized type IVB secretion system (T4SS) that delivers effectors essential for intracellular replication and CCV formation. Using a bioinformatics-guided approach, 234 T4SS candidate substrates were identified. Expression of each candidate as a TEM-1 β-lactamase fusion protein led to the identification of 53 substrates that were translocated in a Dot/Icm-dependent manner. Ectopic expression in HeLa cells revealed that these substrates trafficked to distinct subcellular sites, including the endoplasmic reticulum, mitochondrion, and nucleus. Expression in
Saccharomyces cerevisiae
identified several substrates that were capable of interfering with yeast growth, suggesting that these substrates target crucial host processes. To determine if any of these T4SS substrates are necessary for intracellular replication, we isolated 20 clonal T4SS substrate mutants using the
Himar1
transposon and transposase. Among these, 10 mutants exhibited defects in intracellular growth and CCV formation in HeLa and J774A.1 cells but displayed normal growth in bacteriological medium. Collectively, these results indicate that
C. burnetii
encodes a large repertoire of T4SS substrates that play integral roles in host cell subversion and CCV formation and suggest less redundancy in effector function than has been found in the comparative
Legionella
Dot/Icm model.
Details
- Title: Subtitle
- Identification of Coxiella burnetii Type IV Secretion Substrates Required for Intracellular Replication and Coxiella-Containing Vacuole Formation
- Creators
- Mary M Weber - Department of Microbial and Molecular Pathogenesis, Texas A&M Health Science Center, College of Medicine, Bryan, Texas, USAChen Chen - Department of Microbial and Molecular Pathogenesis, Texas A&M Health Science Center, College of Medicine, Bryan, Texas, USAKristina Rowin - Department of Microbial and Molecular Pathogenesis, Texas A&M Health Science Center, College of Medicine, Bryan, Texas, USAKatja Mertens - Department of Microbial and Molecular Pathogenesis, Texas A&M Health Science Center, College of Medicine, Bryan, Texas, USAGloria Galvan - Department of Microbial and Molecular Pathogenesis, Texas A&M Health Science Center, College of Medicine, Bryan, Texas, USAHui Zhi - Department of Microbial and Molecular Pathogenesis, Texas A&M Health Science Center, College of Medicine, Bryan, Texas, USAChristopher M Dealing - Department of Microbial and Molecular Pathogenesis, Texas A&M Health Science Center, College of Medicine, Bryan, Texas, USAVictor A Roman - Department of Biological Sciences, Purdue University, West Lafayette, Indiana, USASimran Banga - Department of Biological Sciences, Purdue University, West Lafayette, Indiana, USAYunhao Tan - Department of Biological Sciences, Purdue University, West Lafayette, Indiana, USAZhao-Qing Luo - Department of Biological Sciences, Purdue University, West Lafayette, Indiana, USAJames E Samuel - Department of Microbial and Molecular Pathogenesis, Texas A&M Health Science Center, College of Medicine, Bryan, Texas, USA
- Resource Type
- Journal article
- Publication Details
- Journal of bacteriology, Vol.195(17), pp.3914-3924
- Publisher
- American Society for Microbiology
- DOI
- 10.1128/JB.00071-13
- PMID
- 23813730
- PMCID
- PMC3754607
- ISSN
- 0021-9193
- eISSN
- 1098-5530
- Language
- English
- Date published
- 09/2013
- Academic Unit
- Microbiology and Immunology
- Record Identifier
- 9984083883102771
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