title: 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.
authors.affiliation: Department of Microbiology, University of Georgia, Athens, Georgia 30602, USA.
authors.forename: D B
authors.initials: DB
authors.lastname: Kearns
authors.forename: J
authors.initials: J
authors.lastname: Robinson
authors.forename: L J
authors.initials: LJ
authors.lastname: Shimkets
mesh_terms: D002630:Chemotactic Factors / Q000302:isolation & purification*; D002633:Chemotaxis / Q000502:physiology*; D004305:Dose-Response Relationship, Drug; D010714:Phosphatidylethanolamines / Q000494:pharmacology*; D011550:Pseudomonas aeruginosa / Q000502:physiology*; D013329:Structure-Activity Relationship
chemical_list: D002630:Chemotactic Factors; D010714:Phosphatidylethanolamines; C094877:dioleoyl phosphatidylethanolamine; C007445:1,2-dilauroylphosphatidylethanolamine