title: Mapping the twin-arginine protein translocation network of Bacillus subtilis.
abstract: Bacteria employ twin-arginine translocation (Tat) pathways for the transport of folded proteins to extracytoplasmic destinations. In recent years, most studies on bacterial Tat pathways addressed the membrane-bound TatA(B)C subunits of the Tat translocase, and the specific interactions between this translocase and its substrate proteins. In contrast, relatively few studies investigated possible coactors in the TatA(B)C-dependent protein translocation process. The present studies were aimed at identifying interaction partners of the Tat pathway of Bacillus subtilis, which is a paradigm for studies on protein secretion by Gram-positive bacteria. Specifically, 36 interaction partners of the TatA and TatC subunits were identified by rigorous application of the yeast two-hybrid (Y2H) approach. Our Y2H analyses revealed that the three TatA isoforms of B. subtilis can form homo- and heterodimers. Subsequently, the secretion of the Tat substrates YwbN and PhoD was tested in mutant strains lacking genes for the TatAC interaction partners identified in our genome-wide Y2H screens. Our results show that the cell wall-bound protease WprA is important for YwbN secretion, and that the HemAT and CsbC proteins are required for PhoD secretion under phosphate starvation conditions. Taken together, our findings imply that the Bacillus Tat pathway is embedded in an intricate protein-protein interaction network.
authors.affiliation: Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands.
authors.forename: Carmine G
authors.initials: CG
authors.lastname: Monteferrante
authors.forename: Calum
authors.initials: C
authors.lastname: MacKichan
authors.forename: Elodie
authors.initials: E
authors.lastname: Marchadier
authors.forename: Maria-Victoria
authors.initials: MV
authors.lastname: Prejean
authors.forename: Rut
authors.initials: R
authors.lastname: Carballido-López
authors.forename: Jan Maarten
authors.initials: JM
authors.lastname: van Dijl
mesh_terms: D001412:Bacillus subtilis / Q000378:metabolism*; D001426:Bacterial Proteins / Q000378:metabolism*; D042541:Intracellular Space / Q000737:chemistry / Q000378:metabolism; D026901:Membrane Transport Proteins / Q000378:metabolism*; D009154:Mutation; D060066:Protein Interaction Maps; D040901:Proteomics / Q000379:methods; D012697:Serine Endopeptidases / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D026901:Membrane Transport Proteins; D012697:Serine Endopeptidases; C104015:WprA protein, Bacillus subtilis