PUBLICATION
EsxA membrane-permeabilizing activity plays a key role in mycobacterial cytosolic translocation and virulence: effects of single-residue mutations at glutamine 5
- Authors
- Zhang, Q., Wang, D., Jiang, G., Liu, W., Deng, Q., Li, X., Qian, W., Ouellet, H., Sun, J.
- ID
- ZDB-PUB-160908-3
- Date
- 2016
- Source
- Scientific Reports 6: 32618 (Journal)
- Registered Authors
- Keywords
- Membranes, Pathogens
- MeSH Terms
-
- Amino Acid Sequence
- Animals
- Antigens, Bacterial/chemistry
- Antigens, Bacterial/genetics*
- Antigens, Bacterial/metabolism
- Bacterial Adhesion/genetics
- Bacterial Proteins/chemistry
- Bacterial Proteins/genetics*
- Bacterial Proteins/metabolism
- Cell Line
- Cell Membrane Permeability
- Cytosol/metabolism*
- Down-Regulation/genetics
- Embryo, Nonmammalian/metabolism
- Gene Expression Regulation, Bacterial
- Genetic Complementation Test
- Glutamine/genetics*
- Homologous Recombination/genetics
- Humans
- Mice
- Microbial Viability/genetics
- Mutation/genetics*
- Mycobacterium tuberculosis/genetics*
- Mycobacterium tuberculosis/growth & development
- Mycobacterium tuberculosis/pathogenicity*
- Protein Transport
- Up-Regulation/genetics
- Virulence
- Zebrafish/embryology
- PubMed
- 27600772 Full text @ Sci. Rep.
Citation
Zhang, Q., Wang, D., Jiang, G., Liu, W., Deng, Q., Li, X., Qian, W., Ouellet, H., Sun, J. (2016) EsxA membrane-permeabilizing activity plays a key role in mycobacterial cytosolic translocation and virulence: effects of single-residue mutations at glutamine 5. Scientific Reports. 6:32618.
Abstract
EsxA is required for virulence of Mycobacterium tuberculosis (Mtb) and plays an essential role in phagosome rupture and translocation to the cytosol of macrophages. Recent biochemical studies have demonstrated that EsxA is a membrane-permeabilizing protein. However, evidence that link EsxA membrane-permeabilizing activity to Mtb cytosolic translocation and virulence is lacking. Here we found that mutations at glutamine 5 (Q5) could up or down regulate EsxA membrane-permeabilizing activity. The mutation Q5K significantly diminished the membrane-permeabilizing activity, while Q5V enhanced the activity. By taking advantage of the single-residue mutations, we tested the effects of EsxA membrane-permeabilizing activity on mycobacterial virulence and cytosolic translocation using the esxA/esxB knockout strains of Mycobacterium marinum (Mm) and Mtb. Compared to wild type (WT), the Q5K mutant exhibited significantly attenuated virulence, evidenced by intracellular survival and cytotoxicity in mouse macrophages as well as infection of zebra fish embryos. The attenuated virulence of the Q5K mutant was correlated to the impaired cytosolic translocation. On the contrary, the Q5V mutant had a significantly increased cytosolic translocation and showed an overall increased virulence. This study provides convincing evidence that EsxA contributes to mycobacterial virulence with its membrane-permeabilizing activity that is required for cytosolic translocation.
Genes / Markers
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Orthology
Engineered Foreign Genes
Mapping