Nitrile-inducible gene expression in mycobacteria

Area of Science:

• Microbiology
• Molecular Biology
• Bacterial Genetics

Background:

• Ectopic gene expression control is vital for studying bacterial physiology and pathogenesis.
• Existing inducible expression systems are often inefficient in phylogenetically distant bacteria like mycobacteria.

Purpose of the Study:

• To adapt a highly-inducible regulon from Rhodococcus rhodochrous for artificial gene regulation in mycobacteria.
• To establish a controllable gene expression system for both environmental and pathogenic mycobacteria, including Mycobacterium tuberculosis.

Main Methods:

• Adaptation of the Rhodococcus rhodochrous regulon for use in mycobacterial species.
• Demonstration of the system's function as a bistable switch.
• Testing the system's efficacy in vitro across different growth phases and during intracellular growth in macrophages.

Main Results:

• The adapted regulatory circuit functions as a bistable switch in mycobacteria.
• Gene expression can be manipulated regardless of growth phase, both in vitro and during intracellular growth.
• High-level protein overexpression is achievable, facilitating biochemical and structural analyses.

Conclusions:

• The Rhodococcus rhodochrous regulon provides a versatile and effective tool for inducible gene expression in mycobacteria.
• This system overcomes limitations of existing methods, enabling advanced research into mycobacterial biology and pathogenesis.
• The ability to control gene expression, even during intracellular growth, opens new avenues for studying Mycobacterium tuberculosis and related species.