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Gram-negative Bacterial Protein Secretion Systems

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Transmembrane substrates of type three secretion system injectisomes.

Camilla Godlee^1,2, David W Holden¹

¹MRC Centre for Molecular Bacteriology and Infection, Imperial College London, Armstrong Road, London SW7 2AZ, UK.

Microbiology (Reading, England)

|February 7, 2023

Summary

Gram-negative bacteria use a type three secretion system injectisome to deliver virulence effectors into host cells. This review details how these bacterial proteins integrate into host membranes and their functions.

Keywords:

effector injectisome membrane integration translocon type three secretion system

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Area of Science:

Microbiology
Cell Biology
Pathogenesis

Background:

Gram-negative bacterial pathogens utilize the type three secretion system (T3SS) injectisome to translocate effector proteins into host cells.
These effectors are crucial for bacterial invasion, replication, immune evasion, and transmission.

Approach:

This review focuses on transmembrane translocon proteins and effectors secreted by the injectisome.
It examines the mechanisms of their integration into host cell membranes and the functional consequences of their localization.

Key Points:

The injectisome forms a pore in the host cell membrane for effector delivery.
Some effectors integrate into host membranes, performing unique biochemical functions.
Both translocon proteins and transmembrane effectors avoid aggregation and improper localization within the bacterial cell.

Conclusions:

Understanding the membrane integration of bacterial effectors is key to comprehending host-pathogen interactions.
The localization of injectisome effectors within host membranes confers specific functional advantages for bacterial pathogens.