title: ClpXP protease degrades the cytoskeletal protein, FtsZ, and modulates FtsZ polymer dynamics.
abstract: FtsZ is the major cytoskeletal protein in bacteria and a tubulin homologue. It polymerizes and forms a ring where constriction occurs to divide the cell. We found that FtsZ is degraded by E. coli ClpXP, an ATP-dependent protease. In vitro, ClpXP degrades both FtsZ protomers and polymers; however, polymerized FtsZ is degraded more rapidly than the monomer. Deletion analysis shows that the N-terminal domain of ClpX is important for polymer recognition and that the FtsZ C terminus contains a ClpX recognition signal. In vivo, FtsZ is turned over slower in a clpX deletion mutant compared with a WT strain. Overexpression of ClpXP results in increased FtsZ degradation and filamentation of cells. These results suggest that ClpXP may participate in cell division by modulating the equilibrium between free and polymeric FtsZ via degradation of FtsZ filaments and protomers.
authors.affiliation: Laboratory of Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
authors.forename: Jodi L
authors.initials: JL
authors.lastname: Camberg
authors.forename: Joel R
authors.initials: JR
authors.lastname: Hoskins
authors.forename: Sue
authors.initials: S
authors.lastname: Wickner
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D015153:Blotting, Western; D002384:Catalysis / Q000187:drug effects; D003598:Cytoskeletal Proteins / Q000235:genetics / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D049071:Endopeptidase Clp / Q000235:genetics / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D006160:Guanosine Triphosphate / Q000378:metabolism / Q000494:pharmacology; D018613:Microscopy, Confocal; D008856:Microscopy, Fluorescence; D009154:Mutation; D011108:Polymers / Q000378:metabolism*; D013379:Substrate Specificity
chemical_list: D001426:Bacterial Proteins; D003598:Cytoskeletal Proteins; D029968:Escherichia coli Proteins; C071525:FtsZ protein, Bacteria; D011108:Polymers; D006160:Guanosine Triphosphate; D000255:Adenosine Triphosphate; C483573:ClpXP protease, E coli; D049071:Endopeptidase Clp