Interplay of the serine/threonine-kinase StkP and the paralogs DivIVA and GpsB in pneumococcal cell elongation and division.
Despite years of intensive research, much remains to be discovered to understand the regulatory networks coordinating bacterial cell growth and division. The mechanisms by which Streptococcus pneumoniae achieves its characteristic ellipsoid-cell shape remain largely unknown. In this study, we analyzed the interplay of the cell division paralogs DivIVA and GpsB with the ser/thr kinase StkP. We observed that the deletion of divIVA hindered cell elongation and resulted in cell shortening and rounding. By contrast, the absence of GpsB resulted in hampered cell division and triggered cell elongation. Remarkably, ΔgpsB elongated cells exhibited a helical FtsZ pattern instead of a Z-ring, accompanied by helical patterns for DivIVA and peptidoglycan synthesis. Strikingly, divIVA deletion suppressed the elongated phenotype of ΔgpsB cells. These data suggest that DivIVA promotes cell elongation and that GpsB counteracts it. Analysis of protein-protein interactions revealed that GpsB and DivIVA do not interact with FtsZ but with the cell division protein EzrA, which itself interacts with FtsZ. In addition, GpsB interacts directly with DivIVA. These results are consistent with DivIVA and GpsB acting as a molecular switch to orchestrate peripheral and septal PG synthesis and connecting them with the Z-ring via EzrA. The cellular co-localization of the transpeptidases PBP2x and PBP2b as well as the lipid-flippases FtsW and RodA in ΔgpsB cells further suggest the existence of a single large PG assembly complex. Finally, we show that GpsB is required for septal localization and kinase activity of StkP, and therefore for StkP-dependent phosphorylation of DivIVA. Altogether, we propose that the StkP/DivIVA/GpsB triad finely tunes the two modes of peptidoglycan (peripheral and septal) synthesis responsible for the pneumococcal ellipsoid cell shape.
Bases Moléculaires et Structurales des Systèmes Infectieux, IBCP, Université Lyon 1, CNRS, UMR 5086, Lyon, France.
Aurore
A
Fleurie
Bases Moléculaires et Structurales des Systèmes Infectieux, IBCP, Université Lyon 1, CNRS, UMR 5086, Lyon, France.
Sylvie
S
Manuse
Bases Moléculaires et Structurales des Systèmes Infectieux, IBCP, Université Lyon 1, CNRS, UMR 5086, Lyon, France; Key laboratory of Medical Molecular Virology, School of Basic Medical Sciences, Shanghai Medical College, Fudan University, Shanghai, China.
Chao
C
Zhao
Centre National de la Recherche Scientifique, LMGM-UMR5100, Toulouse, France; Université de Toulouse, UPS, Laboratoire de Microbiologie et Génétique Moléculaires, Toulouse, France.
Nathalie
N
Campo
Laboratoire de Biologie Tissulaire et d'Ingénierie Thérapeutique, IBCP, Université Lyon 1, CNRS, UMR5305, Lyon, France.
Caroline
C
Cluzel
Bases Moléculaires et Structurales des Systèmes Infectieux, IBCP, Université Lyon 1, CNRS, UMR 5086, Lyon, France.
Jean-Pierre
JP
Lavergne
Bases Moléculaires et Structurales des Systèmes Infectieux, IBCP, Université Lyon 1, CNRS, UMR 5086, Lyon, France.
Céline
C
Freton
Bases Moléculaires et Structurales des Systèmes Infectieux, IBCP, Université Lyon 1, CNRS, UMR 5086, Lyon, France.
Christophe
C
Combet
Bases Moléculaires et Structurales des Systèmes Infectieux, IBCP, Université Lyon 1, CNRS, UMR 5086, Lyon, France.
Sébastien
S
Guiral
Proteome Center Tuebingen, Interdepartmental Institute for Cell Biology, University of Tuebingen, Tuebingen, Germany.
Boumediene
B
Soufi
Proteome Center Tuebingen, Interdepartmental Institute for Cell Biology, University of Tuebingen, Tuebingen, Germany.
Boris
B
Macek
Departments of Biology and Chemistry, Indiana University, Bloomington, Indiana, United States of America.
Erkin
E
Kuru
Departments of Biology and Chemistry, Indiana University, Bloomington, Indiana, United States of America.
Michael S
MS
VanNieuwenhze
Departments of Biology and Chemistry, Indiana University, Bloomington, Indiana, United States of America.
Yves V
YV
Brun
Institut de Biologie Structurale, UMR 5075, Université Joseph Fourier, CNRS, CEA, Grenoble, France.
Anne-Marie
AM
Di Guilmi
Centre National de la Recherche Scientifique, LMGM-UMR5100, Toulouse, France; Université de Toulouse, UPS, Laboratoire de Microbiologie et Génétique Moléculaires, Toulouse, France.
Jean-Pierre
JP
Claverys
Laboratoire de Chimie Bactérienne, UMR7283, IMM, CNRS, Aix-Marseille Université, Marseille, France.
Anne
A
Galinier
Bases Moléculaires et Structurales des Systèmes Infectieux, IBCP, Université Lyon 1, CNRS, UMR 5086, Lyon, France.
Christophe
C
Grangeasse
D001426:Bacterial Proteins / Q000378:metabolism; D018797:Cell Cycle Proteins / Q000378:metabolism; D002455:Cell Division / Q000235:genetics / Q000502:physiology*; D002473:Cell Wall / Q000378:metabolism; D003598:Cytoskeletal Proteins / Q000378:metabolism; D009024:Morphogenesis / Q000502:physiology; D010457:Peptidoglycan / Q000378:metabolism; D010766:Phosphorylation / Q000235:genetics / Q000502:physiology; D060066:Protein Interaction Maps / Q000502:physiology; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D013296:Streptococcus pneumoniae / Q000235:genetics / Q000378:metabolism*
D001426:Bacterial Proteins; D018797:Cell Cycle Proteins; D003598:Cytoskeletal Proteins; D010457:Peptidoglycan; D017346:Protein Serine-Threonine Kinases