title: Methyl 3-Hydroxymyristate, a Diffusible Signal Mediating phc Quorum Sensing in Ralstonia solanacearum.
abstract: Ralstonia solanacearum, a plant pathogenic bacterium causing "bacterial wilt" on crops, uses a quorum sensing (QS) system consisting of phc regulatory elements to control its virulence. Methyl 3-hydroxypalmitate (3-OH PAME) was previously identified as the QS signal in strain AW1. However, 3-OH PAME has not been reportedly detected from any other strains, and this suggests that they produce another unknown QS signal. Here we identify (R)-methyl 3-hydroxymyristate [(R)-3-OH MAME] as a new QS signal that regulates the production of virulence factors and secondary metabolites. (R)-3-OH MAME was synthesized by the methyltransferase PhcB and sensed by the histidine kinase PhcS. The phylogenetic trees of these proteins from R. solanacearum strains were divided into two groups, according to their QS signal types--(R)-3-OH MAME or (R)-3-OH PAME. These results demonstrate that (R)-3-OH MAME is another crucial QS signal and highlight the unique evolution of QS systems in R. solanacearum.
authors.affiliation: Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka, 599-8531, Japan. kai@biochem.osakafu-u.ac.jp.
authors.forename: Kenji
authors.initials: K
authors.lastname: Kai
authors.affiliation: Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka, 599-8531, Japan.
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Ohnishi
authors.affiliation: Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka, 599-8531, Japan.
authors.forename: Mika
authors.initials: M
authors.lastname: Shimatani
authors.affiliation: Laboratory of Plant Pathology and Biotechnology, Kochi University, 200 Otsu, Monobe, Nanko-ku, Kochi, 783-8502, Japan.
authors.forename: Shiho
authors.initials: S
authors.lastname: Ishikawa
authors.affiliation: Laboratory of Plant Pathology and Biotechnology, Kochi University, 200 Otsu, Monobe, Nanko-ku, Kochi, 783-8502, Japan.
authors.forename: Yuka
authors.initials: Y
authors.lastname: Mori
authors.affiliation: Laboratory of Plant Pathology and Biotechnology, Kochi University, 200 Otsu, Monobe, Nanko-ku, Kochi, 783-8502, Japan.
authors.forename: Akinori
authors.initials: A
authors.lastname: Kiba
authors.affiliation: Research Institute of Molecular Genetics, Kochi University, 200 Otsu, Monobe, Nanko-ku, Kochi, 783-8502, Japan.
authors.forename: Kouhei
authors.initials: K
authors.lastname: Ohnishi
authors.affiliation: Faculty of Agriculture, Kagawa University, 2393 Ikenobe, Miki-cho, Kagawa, 761-0795, Japan.
authors.forename: Mitsuaki
authors.initials: M
authors.lastname: Tabuchi
authors.affiliation: Laboratory of Plant Pathology and Biotechnology, Kochi University, 200 Otsu, Monobe, Nanko-ku, Kochi, 783-8502, Japan.
authors.forename: Yasufumi
authors.initials: Y
authors.lastname: Hikichi
mesh_terms: D001426:Bacterial Proteins / Q000145:classification / Q000235:genetics / Q000378:metabolism; D001688:Biological Products / Q000737:chemistry / Q000378:metabolism; D008401:Gas Chromatography-Mass Spectrometry; D009226:Myristates / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D010169:Palmitic Acids / Q000737:chemistry* / Q000378:metabolism; D010802:Phylogeny; D053038:Quorum Sensing / Q000235:genetics / Q000502:physiology*; D043368:Ralstonia solanacearum / Q000235:genetics* / Q000378:metabolism*; D050436:Regulatory Elements, Transcriptional / Q000235:genetics; D013237:Stereoisomerism; D013329:Structure-Activity Relationship; D037521:Virulence Factors / Q000235:genetics / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D001688:Biological Products; D009226:Myristates; D010169:Palmitic Acids; D037521:Virulence Factors; C000609565:methyl 3-hydroxymyristate; C108229:3-hydroxypalmitic acid
keywords: Ralstonia solanacearum; diffusible signals; natural products; quorum sensing; structure elucidation