Pseudomonas aeruginosa Exhibits Directed Twitching Motility Up Phosphatidylethanolamine Gradients

Abstract

Pseudomonas aeruginosa translocates over solid surfaces by a type IV pilus-dependent form of multicellular motility known as twitching. We wondered whether cells utilize endogenous factors to organize twitching, and we purified from wild-type cells a lipid that caused directed movement. Wild-type P. aeruginosa, but not a pilJ pilus-deficient mutant, showed biased movement up gradients of phosphatidylethanolamine (PE) established in agar. Activity was related to the fatty acid composition of the lipid, as two synthetic PE species, dilauroyl and dioleoyl PE, were capable of directing P. aeruginosa motility while many other species were inactive. P. aeruginosa PE did not contain either laurate or oleate, implying that the native attractant species contains different fatty acids. Uniform concentrations of PE increased cell velocity, suggesting that chemokinesis may be at least partly responsible for directed movement. We speculate that PE-directed twitching motility may be involved in biofilm formation and pathogenesis.

High Specificity in CheR Methyltransferase Function

“…Here we show that the mutation of the WspC homologue in P. putida reduces biofilm formation, which is consistent with the above findings. The chP chemosensory pathway of P. aeruginosa was found to mediate type IV pilibased motility (32)(33)(34). To assess whether CheR3 may potentially be involved in mediating this type of motility, we have thus studied the twitching motility of P. putida KT2440.…”

“…The third pathway (wsp) (31) regulates cyclic diguanylate concentrations (formed by the cluster III gene products), which in turn was found to modulate biofilm formation. The fourth pathway, chP (cluster IV genes), modulates the cAMP level (32) and consequently several other features including type IV pili synthesis and twitching motility (33,34). Because the signaling proteins of these pathways are paralogous, there thus exists the possibility of cross-talk between pathways.…”

Sinorhizobial chemotaxis: a departure from the enterobacterial paradigm a aTo Professor Wolfram Heumann on his 87th birthday.

“…A second set of che genes revealed by the complete S. meliloti genome sequence (Galibert et al, 2001) is located on the pSymA replicon and linked to genes that control type IV pilus synthesis. Together, the taxis-and pilus-coding genes may have a role in gliding (or twitching) motility (Kearns et al, 2001) appropriate for colonizing the host plant. While it is conceivable that multiple che operons in one cell may interact in a synergistic fashion, the two reported cases rather suggest that these operons specify distinctive sensory pathways operating under diverse and rather specific environmental conditions.…”

Pseudomonas aeruginosa LecB Is Involved in Pilus Biogenesis and Protease IV Activity but Not in Adhesion to Respiratory Mucins

“…In P. aeruginosa, twitching motility is mediated by type IV pili and is controlled by a complex chemosensory pathway comprised of the proteins PilG, PilH, PilI, PilJ, PilK, ChpA, ChpB, and ChpC (30). Kearns et al (13) had observed that a P. aeruginosa pilJ mutant was deficient in twitching motility and expressed no type IV pili. Therefore, the twitching motility phenotype of the mutants was examined via the subsurface stab assay.…”