title: Phosphorylation of the cell division protein GpsB regulates PrkC kinase activity through a negative feedback loop in Bacillus subtilis.
abstract: Although many membrane Ser/Thr-kinases with PASTA motifs have been shown to control bacterial cell division and morphogenesis, inactivation of the Ser/Thr-kinase PrkC does not impact Bacillus subtilis cell division. In this study, we show that PrkC localizes at the division septum. In addition, three proteins involved in cell division/elongation, GpsB, DivIVA and EzrA are required for stimulating PrkC activity in vivo. We show that GpsB interacts with the catalytic subunit of PrkC that, in turn, phosphorylates GpsB. These observations are not made with DivIVA and EzrA. Consistent with the phosphorylated residue previously detected for GpsB in a high-throughput phosphoproteomic analysis of B. subtilis, we show that threonine 75 is the single PrkC-mediated phosphorylation site in GpsB. Importantly, the substitution of this threonine by a phospho-mimetic residue induces a loss of PrkC kinase activity in vivo and a reduced growth under high salt conditions as observed for gpsB and prkC null mutants. Conversely, substitution of threonine 75 by a phospho-ablative residue does not induce such growth and PrkC kinase activity defects. Altogether, these data show that proteins of the divisome control PrkC activity and thereby phosphorylation of PrkC substrates through a negative feedback loop in B. subtilis.
authors.affiliation: Laboratoire de Chimie Bactérienne, UMR 7283, IMM, CNRS, Aix-Marseille Université, 31 Chemin Joseph Aiguier, Marseille, 13009, France.
authors.forename: Frédérique
authors.initials: F
authors.lastname: Pompeo
authors.affiliation: Laboratoire de Chimie Bactérienne, UMR 7283, IMM, CNRS, Aix-Marseille Université, 31 Chemin Joseph Aiguier, Marseille, 13009, France.
authors.forename: Elodie
authors.initials: E
authors.lastname: Foulquier
authors.affiliation: Laboratoire de Chimie Bactérienne, UMR 7283, IMM, CNRS, Aix-Marseille Université, 31 Chemin Joseph Aiguier, Marseille, 13009, France.
authors.forename: Bastien
authors.initials: B
authors.lastname: Serrano
authors.affiliation: Bases Moléculaires et Structurales des Systèmes Infectieux, IBCP, CNRS, UMR, Université Lyon 1, Lyon, 5086, France.
authors.forename: Christophe
authors.initials: C
authors.lastname: Grangeasse
authors.affiliation: Laboratoire de Chimie Bactérienne, UMR 7283, IMM, CNRS, Aix-Marseille Université, 31 Chemin Joseph Aiguier, Marseille, 13009, France.
authors.forename: Anne
authors.initials: A
authors.lastname: Galinier
mesh_terms: D001412:Bacillus subtilis / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D020134:Catalytic Domain; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism*; D002455:Cell Division; D025461:Feedback, Physiological; D010766:Phosphorylation; D011493:Protein Kinase C / Q000737:chemistry / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D012694:Serine / Q000378:metabolism; D013912:Threonine / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D018797:Cell Cycle Proteins; D013912:Threonine; D012694:Serine; D011493:Protein Kinase C