title: Novel twin-arginine translocation pathway-dependent phenotypes of Bacillus subtilis unveiled by quantitative proteomics.
abstract: The twin-arginine translocation (Tat) pathway is known to translocate fully folded proteins across bacterial, archaeal, and organellar membranes. To date, the mechanisms involved in processing, proofreading, and quality control of Tat substrates have remained largely elusive. Bacillus subtilis is an industrially relevant Gram-positive model bacterium. The Tat pathway in B. subtilis differs from that of other well-studied organisms in that it is composed of two complexes operating in parallel. To obtain a better understanding of this pathway in B. subtilis and to identify Tat-associated proteins, the B. subtilis 'Tat proteome' was investigated by quantitative proteomics. Metabolically labeled proteins from cytoplasmic, membrane, and extracellular fractions were analyzed by LC-MS/MS. Changes in the amounts of identified peptides allowed for quantitative comparisons of their abundance in tat mutant strains. The observed differences were suggestive of indirect or direct protein-protein relationships. The rich data set generated was then approached in hypothesis-driving and hypothesis-driven manners. The hypothesis-driving approach led to the identification of a novel delayed biofilm phenotype of certain tat mutant strains, whereas the hypothesis-driven approach identified the membrane protein QcrA as a new Tat substrate of B. subtilis. Thus, our quantitative proteomics analyses have unveiled novel Tat pathway-dependent phenotypes in Bacillus.
authors.affiliation: Department of Medical Microbiology, University of Groningen, Hanzeplein 1, P.O. Box 30001, 9700 RB Groningen, The Netherlands.
authors.forename: Vivianne J
authors.initials: VJ
authors.lastname: Goosens
authors.forename: Andreas
authors.initials: A
authors.lastname: Otto
authors.forename: Corinna
authors.initials: C
authors.lastname: Glasner
authors.forename: Carmine C
authors.initials: CC
authors.lastname: Monteferrante
authors.forename: René
authors.initials: R
authors.lastname: van der Ploeg
authors.forename: Michael
authors.initials: M
authors.lastname: Hecker
authors.forename: Dörte
authors.initials: D
authors.lastname: Becher
authors.forename: Jan Maarten
authors.initials: JM
authors.lastname: van Dijl
mesh_terms: D001120:Arginine / Q000737:chemistry*; D001412:Bacillus subtilis / Q000378:metabolism*; D018441:Biofilms / Q000254:growth & development; D002462:Cell Membrane / Q000378:metabolism; D002853:Chromatography, Liquid; D003593:Cytoplasm / Q000378:metabolism; D005110:Extracellular Space / Q000378:metabolism; D026901:Membrane Transport Proteins / Q000302:isolation & purification* / Q000378:metabolism; D010641:Phenotype; D021381:Protein Transport; D040901:Proteomics; D053719:Tandem Mass Spectrometry
chemical_list: D026901:Membrane Transport Proteins; D001120:Arginine