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Phosphate responsive regulation provides insights for ESX-5 function in Mycobacterium tuberculosis
Sarah R Elliott1, Anna D Tischler2,3
1Department of Microbiology and Immunology, University of Minnesota Twin Cities, Minneapolis, MN, 55455, USA.
Current Genetics
|April 24, 2016
Summary
The phosphate sensing system Pst/SenX3-RegX3 directly activates Mycobacterium tuberculosis's ESX-5 secretion in response to low phosphate. This finding reveals a regulatory mechanism linked to virulence and phosphate acquisition.
Area of Science:
- Microbiology
- Molecular Biology
- Pathogenesis
Background:
- Pathogenic microbes utilize specialized secretion systems to respond to host environmental cues.
- Mycobacterium tuberculosis employs Type VII ESX secretion systems for effector protein transport.
- The ESX-5 secretion system's role in virulence is established, but its regulatory mechanism and activating signal remained unclear.
Purpose of the Study:
- To elucidate the regulatory mechanism and activating signal for the ESX-5 secretion system in Mycobacterium tuberculosis.
- To investigate the link between phosphate sensing and ESX-5 activation.
- To understand the biological roles of ESX-5 in pathogenesis and nutrient acquisition.
Main Methods:
- Investigated the interaction between the Pst/SenX3-RegX3 phosphate sensing system and the ESX-5 secretion system.
- Analyzed the response of ESX-5 secretion under conditions of phosphate limitation.
- Utilized genetic and biochemical approaches to validate regulatory links.
Main Results:
- Demonstrated direct activation of ESX-5 secretion by the Pst/SenX3-RegX3 system.
- Identified phosphate limitation as the environmental signal triggering ESX-5 activation.
- Established a regulatory network connecting phosphate homeostasis to ESX-5 function.
Conclusions:
- The Pst/SenX3-RegX3 system directly regulates ESX-5 secretion in response to phosphate scarcity.
- ESX-5 secretion is a key component in Mycobacterium tuberculosis's adaptation to phosphate-limited environments.
- The ESX-5 system likely plays crucial roles in both phosphate acquisition and virulence during infection.
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