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Phosphorylation of the cell division protein GpsB regulates PrkC kinase activity through a negative feedback loop in B acillus subtilis
Author(s) -
Pompeo Frédérique,
Foulquier Elodie,
Serrano Bastien,
Grangeasse Christophe,
Galinier Anne
Publication year - 2015
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/mmi.13015
Subject(s) - biology , threonine , phosphorylation , cell division , microbiology and biotechnology , kinase , serine , protein kinase a , biochemistry , cell growth , cell
Summary Although many membrane S er/ T hr‐kinases with PASTA motifs have been shown to control bacterial cell division and morphogenesis, inactivation of the S er/ T hr‐kinase PrkC does not impact B acillus 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 .