Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Review
. 2021 Mar;115(3):478-489.
doi: 10.1111/mmi.14680. Epub 2021 Jan 29.

Bacterial type VII secretion: An important player in host-microbe and microbe-microbe interactions

Hiu-Ki R Tran  1   2 , Dirk W Grebenc  1   2 , Timothy A Klein  1   2 , John C Whitney  1   2   3
Affiliations
Free article
Review

Bacterial type VII secretion: An important player in host-microbe and microbe-microbe interactions

Hiu-Ki R Tran et al. Mol Microbiol. 2021 Mar.
Free article

Abstract

Type VII secretion systems (T7SSs) are poorly understood protein export apparatuses found in mycobacteria and many species of Gram-positive bacteria. To date, this pathway has predominantly been studied in Mycobacterium tuberculosis, where it has been shown to play an essential role in virulence; however, much less studied is an evolutionarily divergent subfamily of T7SSs referred to as the T7SSb. The T7SSb is found in the major Gram-positive phylum Firmicutes where it was recently shown to target both eukaryotic and prokaryotic cells, suggesting a dual role for this pathway in host-microbe and microbe-microbe interactions. In this review, we compare the current understanding of the molecular architectures and substrate repertoires of the well-studied mycobacterial T7SSa systems to that of recently characterized T7SSb pathways and highlight how these differences may explain the observed biological functions of this understudied protein export machine.

Keywords: Esx secretion; Type VII secretion; bacterial pathogenesis; gram-positive bacteria; interbacterial antagonism.

PubMed Disclaimer

References

REFERENCES

    1. Abdallah, A.M., Bestebroer, J., Savage, N.D., de Punder, K., van Zon, M., Wilson, L. et al (2011) Mycobacterial secretion systems ESX-1 and ESX-5 play distinct roles in host cell death and inflammasome activation. The Journal of Immunology, 187, 4744-4753. https://doi.org/10.4049/jimmunol.1101457
    1. Abdallah, A.M., Gey van Pittius, N.C., Champion, P.A., Cox, J., Luirink, J., Vandenbroucke-Grauls, C.M. et al (2007) Type VII secretion-mycobacteria show the way. Nature Reviews. Microbiology, 5, 883-891.
    1. Abdallah, A.M., Verboom, T., Hannes, F., Safi, M., Strong, M., Eisenberg, D. et al (2006) A specific secretion system mediates PPE41 transport in pathogenic mycobacteria. Molecular Microbiology, 62, 667-679. https://doi.org/10.1111/j.1365-2958.2006.05409.x
    1. Ahmed, M.M., Aboshanab, K.M., Ragab, Y.M., Missiakas, D.M. and Aly, K.A. (2018) The transmembrane domain of the Staphylococcus aureus ESAT-6 component EssB mediates interaction with the integral membrane protein EsaA, facilitating partially regulated secretion in a heterologous host. Archives of Microbiology, 200, 1075-1086. https://doi.org/10.1007/s00203-018-1519-x
    1. Alhajjar, N., Chatterjee, A., Spencer, B.L., Burcham, L.R., Willett, J.L.E., Dunny, G.M. et al (2020) Genome-wide mutagenesis identifies factors involved in Enterococcus faecalis vaginal adherence and persistence. Infection and Immunity, 88. http://dx.doi.org/10.1128/iai.00270-20

Publication types

MeSH terms

Substances

Grants and funding

LinkOut - more resources