Brucella modulates secretory trafficking via multiple type IV secretion effector proteins

Sebenzile Myeni; Robert Child; Tony W Ng; John J Kupko, 3rd; Tara D Wehrly; Stephen F Porcella; Leigh A Knodler; Jean Celli

doi:10.1371/journal.ppat.1003556

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Brucella modulates secretory trafficking via multiple type IV secretion effector proteins

Journal article

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Brucella modulates secretory trafficking via multiple type IV secretion effector proteins

Sebenzile Myeni, Robert Child, Tony W Ng, John J Kupko, 3rd, Tara D Wehrly, Stephen F Porcella, Leigh A Knodler and Jean Celli

PLoS pathogens, Vol.9(8), pp.e1003556-e1003556

2013

DOI: https://doi.org/10.1371/journal.ppat.1003556

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https://hdl.handle.net/2376/113601

PMCID: PMC3738490

PMID: 23950720

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Abstract

Liver - pathology

Brucella abortus - genetics

Humans

Liver - microbiology

Protein Transport - physiology

Brucellosis - pathology

Female

Membrane Proteins - metabolism

Brucellosis - metabolism

Macrophages - microbiology

Vacuoles - genetics

Vacuoles - microbiology

Macrophages - pathology

Membrane Proteins - genetics

Liver - metabolism

Bacterial Proteins - genetics

Bacterial Secretion Systems - physiology

Macrophages - metabolism

Animals

Vacuoles - metabolism

Bacterial Proteins - metabolism

Mice

Mice, Inbred BALB C

HeLa Cells

Brucella abortus - metabolism

The intracellular pathogenic bacterium Brucella generates a replicative vacuole (rBCV) derived from the endoplasmic reticulum via subversion of the host cell secretory pathway. rBCV biogenesis requires the expression of the Type IV secretion system (T4SS) VirB, which is thought to translocate effector proteins that modulate membrane trafficking along the endocytic and secretory pathways. To date, only a few T4SS substrates have been identified, whose molecular functions remain unknown. Here, we used an in silico screen to identify putative T4SS effector candidate proteins using criteria such as limited homology in other bacterial genera, the presence of features similar to known VirB T4SS effectors, GC content and presence of eukaryotic-like motifs. Using β-lactamase and CyaA adenylate cyclase reporter assays, we identified eleven proteins translocated into host cells by Brucella, five in a VirB T4SS-dependent manner, namely BAB1_0678 (BspA), BAB1_0712 (BspB), BAB1_0847 (BspC), BAB1_1671 (BspE) and BAB1_1948 (BspF). A subset of the translocated proteins targeted secretory pathway compartments when ectopically expressed in HeLa cells, and the VirB effectors BspA, BspB and BspF inhibited protein secretion. Brucella infection also impaired host protein secretion in a process requiring BspA, BspB and BspF. Single or combined deletions of bspA, bspB and bspF affected Brucella ability to replicate in macrophages and persist in the liver of infected mice. Taken together, these findings demonstrate that Brucella modulates secretory trafficking via multiple T4SS effector proteins that likely act coordinately to promote Brucella pathogenesis.

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Title: Brucella modulates secretory trafficking via multiple type IV secretion effector proteins
Creators: Sebenzile Myeni - Laboratory of Intracellular Parasites, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, USA
Robert Child
Tony W Ng
John J Kupko, 3rd
Tara D Wehrly
Stephen F Porcella
Leigh A Knodler
Jean Celli
Publication Details: PLoS pathogens, Vol.9(8), pp.e1003556-e1003556
Academic Unit: Paul G. Allen School for Global Animal Health
Publisher: United States
Grant note: AI000954-01 / NIAID NIH HHS Z01 AI000954 / Intramural NIH HHS
Identifiers: 99900547557001842
Language: English
Resource Type: Journal article