title: Xanthomonas citri subsp. citri surface proteome by 2D-DIGE: Ferric enterobactin receptor and other outer membrane proteins potentially involved in citric host interaction.
abstract: Xanthomonas citri subsp. citri (XAC) is the causative agent of citrus canker, a disease of great economic impact around the world. Understanding the role of proteins on XAC cellular surface can provide new insights on pathogen-plant interaction. Surface proteome was performed in XAC grown in vivo (infectious) and in vitro (non-infectious) conditions, by labeling intact cells followed by cellular lysis and direct 2D-DIGE analysis. Seventy-nine differential spots were analyzed by mass spectrometry. Highest relative abundance for in vivo condition was observed for spots containing DnaK protein, 60kDa chaperonin, conserved hypothetical proteins, malate dehydrogenase, phosphomannose isomerase, and ferric enterobactin receptors. Elongation factor Tu, OmpA-related proteins, Oar proteins and some Ton-B dependent receptors were found in spots decreased in vivo. Some proteins identified on XAC's surface in infectious condition and predicted to be cytoplasmic, such as DnaK and 60KDa chaperonin, have also been previously found at cellular surface in other microorganisms. This is the first study on XAC surface proteome and results point to mediation of molecular chaperones in XAC-citrus interaction. The approach utilized here can be applied to other pathogen-host interaction systems and help to achieve new insights in bacterial pathogenicity toward promising targets of biotechnological interest.
  
  
  
  This research provides new insights for current knowledge of the Xanthomonas sp. pathogenicity. For the first time the 2D-DIGE approach was applied on intact cells to find surface proteins involved in the pathogen-plant interaction. Results point to the involvement of new surface/outer membrane proteins in the interaction between XAC and its citrus host and can provide potential targets of biotechnological interest for citrus canker control.
authors.affiliation: Laboratório de Bioquímica e Biologia Molecular Aplicada, Departamento de Genética e Evolução, Universidade Federal de São Carlos, UFSCar, São Carlos, SP, Brazil.
authors.forename: Carolina Moretto
authors.initials: CM
authors.lastname: Carnielli
authors.affiliation: Laboratório de Bioquímica e Biologia Molecular Aplicada, Departamento de Genética e Evolução, Universidade Federal de São Carlos, UFSCar, São Carlos, SP, Brazil.
authors.forename: Juliana
authors.initials: J
authors.lastname: Artier
authors.affiliation: Laboratório de Interações Microbianas, Departamento de Ciências Biológicas, Universidade Federal de São Paulo, UNIFESP, Diadema, SP, Brazil.
authors.forename: Julio Cezar Franco
authors.initials: JC
authors.lastname: de Oliveira
authors.affiliation: Laboratório de Bioquímica e Biologia Molecular Aplicada, Departamento de Genética e Evolução, Universidade Federal de São Carlos, UFSCar, São Carlos, SP, Brazil. Electronic address: marinovo@ufscar.br.
authors.forename: Maria Teresa Marques
authors.initials: MT
authors.lastname: Novo-Mansur
mesh_terms: D001425:Bacterial Outer Membrane Proteins / Q000032:analysis / Q000502:physiology; D001426:Bacterial Proteins / Q000032:analysis; D002352:Carrier Proteins / Q000032:analysis / Q000502:physiology; D002957:Citrus / Q000382:microbiology*; D054884:Host-Pathogen Interactions; D008565:Membrane Proteins / Q000032:analysis / Q000502:physiology; D010935:Plant Diseases / Q000382:microbiology; D020543:Proteome / Q000032:analysis*; D011956:Receptors, Cell Surface / Q000032:analysis / Q000502:physiology; D057825:Two-Dimensional Difference Gel Electrophoresis; D014974:Xanthomonas / Q000737:chemistry / Q000472:pathogenicity*
chemical_list: D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D002352:Carrier Proteins; D008565:Membrane Proteins; D020543:Proteome; D011956:Receptors, Cell Surface; C029489:enterobactin receptor
keywords: 2D-DIGE; Chaperone; Citrus canker; Pathogenicity; Surface proteome; Xanthomonas citri subsp. citri