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Monitoring the Assembly of a Secreted Bacterial Virulence Factor Using Site-specific Crosslinking
Published on: December 17, 2013
Two independent pathways for self-recognition in Proteus mirabilis are linked by type VI-dependent export
Larissa M Wenren1, Nora L Sullivan, Lia Cardarelli
1Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts, USA.
Mbio
|July 25, 2013
Summary
Proteus mirabilis bacteria exhibit self-recognition and territorial behavior through two independent pathways. A type VI secretion system links these pathways, enabling bacteria to distinguish between self and non-self colonies.
Area of Science:
- Microbiology
- Bacterial behavior
- Social interactions in bacteria
Background:
- Swarming colonies of Proteus mirabilis display self-recognition and territorial behavior.
- Distinct swarms recognize foreign isolates and form boundaries, while identical swarms merge.
- The ids genes are crucial but insufficient for this territorial behavior.
Purpose of the Study:
- To identify new gene clusters involved in P. mirabilis self-recognition and territoriality.
- To elucidate the mechanistic basis of bacterial self-recognition and territorial behaviors.
Main Methods:
- Identification of two novel gene clusters: idr (rhs-related products) and tss (type VI secretion apparatus).
- Analysis of the functional independence and interdependence of Ids and Idr proteins.
- Investigation of the role of the type VI secretion system in protein export.
Main Results:
- The idr gene cluster encodes rhs-related products, and the tss cluster encodes a type VI secretion (T6S) apparatus.
- Ids and Idr proteins function independently in extracellular transport and territorial behaviors.
- The T6S system is essential for the export of specific Ids and Idr proteins, linking the two systems.
Conclusions:
- Self-recognition in P. mirabilis involves two independent pathways (Ids and Idr proteins) interconnected by a shared type VI secretion system.
- This T6S system exports key self-recognition elements, providing a mechanistic basis for bacterial territoriality.
- The findings establish a foundation for studying prevalent biological phenomena of self-recognition and territoriality in bacteria.
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