Spatiotemporal control of FlgZ activity impacts Pseudomonas aeruginosa flagellar motility

Area of Science:

• Microbiology
• Bacterial Physiology
• Molecular Biology

Background:

• The opportunistic pathogen Pseudomonas aeruginosa relies on motility for infection.
• The cyclic diguanylate (c-di-GMP) signaling molecule regulates various bacterial behaviors, including motility.
• FlgZ is a known effector protein that binds c-di-GMP and influences motility in P. aeruginosa.

Purpose of the Study:

• To investigate the spatiotemporal activity of FlgZ in P. aeruginosa.
• To elucidate the mechanisms by which FlgZ downregulates bacterial motility.
• To understand the role of FimV in FlgZ-mediated motility control.

Main Methods:

• Re-annotation of the P. aeruginosa flgZ open reading frame.
• Analysis of flgZ gene transcription during different growth phases.
• Microscopy to determine FlgZ localization upon c-di-GMP binding.
• Investigation of FimV's role in FlgZ function.

Main Results:

• FlgZ-mediated motility downregulation is controlled by three independent mechanisms.
• The flgZ gene is transcribed independently during stationary phase, increasing FlgZ protein levels.
• FlgZ localizes to the cell pole after binding c-di-GMP.
• FimV enhances the polar localization of c-di-GMP-bound FlgZ, inhibiting swimming and swarming motility.

Conclusions:

• FlgZ plays a crucial role in fine-tuning bacterial motility in P. aeruginosa.
• Motility regulation involves complex spatiotemporal control of c-di-GMP-dependent pathways.
• The interplay between FimV, FlgZ, and stator proteins represses flagellar-driven motility.