title: A DNA damage checkpoint in Caulobacter crescentus inhibits cell division through a direct interaction with FtsW.
abstract: Following DNA damage, cells typically delay cell cycle progression and inhibit cell division until their chromosomes have been repaired. The bacterial checkpoint systems responsible for these DNA damage responses are incompletely understood. Here, we show that Caulobacter crescentus responds to DNA damage by coordinately inducing an SOS regulon and inhibiting the master regulator CtrA. Included in the SOS regulon is sidA (SOS-induced inhibitor of cell division A), a membrane protein of only 29 amino acids that helps to delay cell division following DNA damage, but is dispensable in undamaged cells. SidA is sufficient, when overproduced, to block cell division. However, unlike many other regulators of bacterial cell division, SidA does not directly disrupt the assembly or stability of the cytokinetic ring protein FtsZ, nor does it affect the recruitment of other components of the cell division machinery. Instead, we provide evidence that SidA inhibits division by binding directly to FtsW to prevent the final constriction of the cytokinetic ring.
authors.affiliation: Department of Biology, Massachusetts Institute of Technology, Cambridge, USA.
authors.forename: Joshua W
authors.initials: JW
authors.lastname: Modell
authors.forename: Alexander C
authors.initials: AC
authors.lastname: Hopkins
authors.forename: Michael T
authors.initials: MT
authors.lastname: Laub
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D016935:Caulobacter crescentus / Q000166:cytology / Q000235:genetics* / Q000378:metabolism*; D002455:Cell Division; D002462:Cell Membrane / Q000378:metabolism; D004249:DNA Damage / Q000502:physiology*; D004268:DNA-Binding Proteins; D015964:Gene Expression Regulation, Bacterial; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D010457:Peptidoglycan / Q000378:metabolism; D014157:Transcription Factors
chemical_list: D001426:Bacterial Proteins; C097706:CtrA protein, Caulobacter; D004268:DNA-Binding Proteins; D008565:Membrane Proteins; D010457:Peptidoglycan; D014157:Transcription Factors; C061684:FtsW protein, Bacteria