title: Quantitative proteomics unravels that the post-transcriptional regulator Crc modulates the generation of vesicles and secreted virulence determinants of Pseudomonas aeruginosa.
abstract: Recent research indicates that the post-transcriptional regulator Crc modulates susceptibility to antibiotics and virulence in Pseudomonas aeruginosa. Several P. aeruginosa virulence factors are secreted or engulfed in vesicles. To decipher the Crc modulation of P. aeruginosa virulence, we constructed a crc deficient mutant and measure the proteome associated extracellular vesicles and the vesicle-free secretome using iTRAQ. Fifty vesicle-associated proteins were more abundant and 14 less abundant in the crc-defective strain, whereas 37 were more abundant and 17 less abundant in the vesicle-free secretome. Among them, virulence determinants, such as ToxA, protease IV, azurin, chitin-binding protein, PlcB and Hcp1, were less abundant in the crc-defective mutant. Transcriptomic analysis revealed that some of the observed changes were post-transcriptional and, thus, could be attributed to a direct Crc regulatory role; whereas, for other differentially secreted proteins, the regulatory role was likely indirect. We also observed that the crc mutant presented an impaired vesicle-associated secretion of quorum sensing signal molecules and less cytotoxicity than its wild-type strain. Our results offer new insights into the mechanisms by which Crc regulates P. aeruginosa virulence, through the modulation of vesicle formation and secretion of both virulence determinants and quorum sensing signals. This article is part of a Special Issue entitled: HUPO 2014.
authors.affiliation: Departamento de Biotecnología Microbiana, Centro Nacional de Biotecnología, CSIC, Madrid, Spain; Departamento de Microbiología II, Facultad de Farmacia, Universidad Complutense de Madrid, Instituto Ramón y Cajal de Investigaciones Sanitarias (IRYCIS), Madrid, Spain.
authors.forename: Jose Antonio
authors.initials: JA
authors.lastname: Reales-Calderón
authors.affiliation: Departamento de Biotecnología Microbiana, Centro Nacional de Biotecnología, CSIC, Madrid, Spain.
authors.forename: Fernando
authors.initials: F
authors.lastname: Corona
authors.affiliation: Departamento de Microbiología II, Facultad de Farmacia, Universidad Complutense de Madrid, Instituto Ramón y Cajal de Investigaciones Sanitarias (IRYCIS), Madrid, Spain.
authors.forename: Lucía
authors.initials: L
authors.lastname: Monteoliva
authors.affiliation: Departamento de Microbiología II, Facultad de Farmacia, Universidad Complutense de Madrid, Instituto Ramón y Cajal de Investigaciones Sanitarias (IRYCIS), Madrid, Spain.
authors.forename: Concha
authors.initials: C
authors.lastname: Gil
authors.affiliation: Departamento de Biotecnología Microbiana, Centro Nacional de Biotecnología, CSIC, Madrid, Spain. Electronic address: jlmtnez@cnb.csic.es.
authors.forename: Jose Luis
authors.initials: JL
authors.lastname: Martínez
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D040901:Proteomics / Q000379:methods*; D011550:Pseudomonas aeruginosa / Q000235:genetics / Q000378:metabolism*; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*; D022142:Secretory Vesicles / Q000235:genetics / Q000378:metabolism*; D037521:Virulence Factors / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D012097:Repressor Proteins; D037521:Virulence Factors; C101896:crc protein, Pseudomonas
keywords: Catabolite repression control (Crc); Extracellular vesicles; Pseudomonas aeruginosa; Quorum sensing; Secretome; Virulence