title: Lipopeptide biosynthesis in Pseudomonas fluorescens is regulated by the protease complex ClpAP.
abstract: BACKGROUND
  Lipopeptides (LP) are structurally diverse compounds with potent surfactant and broad-spectrum antibiotic activities. In Pseudomonas and other bacterial genera, LP biosynthesis is governed by large multimodular nonribosomal peptide synthetases (NRPS). To date, relatively little is known about the regulatory genetic network of LP biosynthesis.
  
  
  RESULTS
  This study provides evidence that the chaperone ClpA, together with the serine protease ClpP, regulates the biosynthesis of the LP massetolide in Pseudomonas fluorescens SS101. Whole-genome transcriptome analyses of clpA and clpP mutants showed their involvement in the transcription of the NRPS genes massABC and the transcriptional regulator massAR. In addition, transcription of genes associated with cell wall and membrane biogenesis, energy production and conversion, amino acid transport and metabolism, and pilus assembly were altered by mutations in clpA and clpP. Proteome analysis allowed the identification of additional cellular changes associated to clpA and clpP mutations. The expression of proteins of the citrate cycle and the heat shock proteins DnaK and DnaJ were particularly affected. Combined with previous findings, these results suggest that the ClpAP complex regulates massetolide biosynthesis via the pathway-specific, LuxR-type regulator MassAR, the heat shock proteins DnaK and DnaJ, and proteins of the TCA cycle.
  
  
  CONCLUSIONS
  Combining transcriptome and proteome analyses provided new insights into the regulation of LP biosynthesis in P. fluorescens and led to the identification of specific missing links in the regulatory pathways.
authors.affiliation: Laboratory of Phytopathology, Wageningen University, 6708 PB, Wageningen, the Netherlands. c.song@nioo.knaw.nl.|Department of Microbial Ecology, Netherlands Institute of Ecology, Droevendaalsesteeg 10, 6708 PB, Wageningen, the Netherlands. c.song@nioo.knaw.nl.
authors.forename: Chunxu
authors.initials: C
authors.lastname: Song
authors.affiliation: Division of Glycoscience, Royal Institute of Technology (KTH), AlbaNova University Centre, SE-106 91, Stockholm, Sweden. gustav_sundqvist@waters.com.
authors.forename: Gustav
authors.initials: G
authors.lastname: Sundqvist
authors.affiliation: Division of Glycoscience, Royal Institute of Technology (KTH), AlbaNova University Centre, SE-106 91, Stockholm, Sweden. erik.malm@biotech.kth.se.
authors.forename: Erik
authors.initials: E
authors.lastname: Malm
authors.affiliation: Department of Microbial Ecology, Netherlands Institute of Ecology, Droevendaalsesteeg 10, 6708 PB, Wageningen, the Netherlands. i.deBruijn@nioo.knaw.nl.
authors.forename: Irene
authors.initials: I
authors.lastname: de Bruijn
authors.affiliation: Division of Plant Pathology, Indian Agricultural Research Institute, New Delhi, 110012, India. kumar@iari.res.in.
authors.forename: Aundy
authors.initials: A
authors.lastname: Kumar
authors.affiliation: Laboratory of Phytopathology, Wageningen University, 6708 PB, Wageningen, the Netherlands. J.vandeMortel@has.nl.|Current address: HAS University of Applied Sciences, 5911 KJ, Venlo, the Netherlands. J.vandeMortel@has.nl.
authors.forename: Judith
authors.initials: J
authors.lastname: van de Mortel
authors.affiliation: Division of Glycoscience, Royal Institute of Technology (KTH), AlbaNova University Centre, SE-106 91, Stockholm, Sweden. bulone@kth.se.
authors.forename: Vincent
authors.initials: V
authors.lastname: Bulone
authors.affiliation: Laboratory of Phytopathology, Wageningen University, 6708 PB, Wageningen, the Netherlands. j.raaijmakers@nioo.knaw.nl.|Department of Microbial Ecology, Netherlands Institute of Ecology, Droevendaalsesteeg 10, 6708 PB, Wageningen, the Netherlands. j.raaijmakers@nioo.knaw.nl.
authors.forename: Jos M
authors.initials: JM
authors.lastname: Raaijmakers
mesh_terms: D017353:Gene Deletion; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D053263:Gene Regulatory Networks; D055666:Lipopeptides / Q000096:biosynthesis*; D018832:Molecular Chaperones / Q000235:genetics / Q000378:metabolism*; D020543:Proteome / Q000032:analysis; D011551:Pseudomonas fluorescens / Q000235:genetics* / Q000378:metabolism*; D057057:Serine Proteases / Q000235:genetics / Q000378:metabolism*
chemical_list: D055666:Lipopeptides; D018832:Molecular Chaperones; D020543:Proteome; D057057:Serine Proteases