Modulation of flagellar rotation in surface-attached bacteria: A pathway for rapid surface-sensing after flagellar attachment
Fig 8
FlhF-FimV interaction is upstream of a cAMP signal in surface-tethered bacteria.
A. The P. aeruginosa flagellar motor C-ring (outlined in blue) interacts with FlhF (blue solid oval) by bacterial 2-hybrid. A GDP-locked allele of FlhF, FlhF(R251G), has stronger and/or more persistent interaction with FimV. This causes an inappropriate cAMP increase in liquid-grown bacteria that inhibits flagellar rotation. B. When bacteria tether at a surface, an undefined “signal” causes a conformational change in FlhF that allows it to interact with FimV. This leads to an increase in intracellular cAMP that stops flagellar rotation and promotes bacterial cell body attachment to a surface. If either FlhF or FimV are absent, the interaction does not occur, cAMP levels do not rise, and bacterial rotation persists in surface-tethered cells.