Cell cycle coordination and regulation of bacterial chromosome segregation dynamics by polarly localized proteins

EMBO J. 2010 Sep 15;29(18):3068-81. doi: 10.1038/emboj.2010.207. Epub 2010 Aug 27.

Abstract

What regulates chromosome segregation dynamics in bacteria is largely unknown. Here, we show in Caulobacter crescentus that the polarity factor TipN regulates the directional motion and overall translocation speed of the parS/ParB partition complex by interacting with ParA at the new pole. In the absence of TipN, ParA structures can regenerate behind the partition complex, leading to stalls and back-and-forth motions of parS/ParB, reminiscent of plasmid behaviour. This extrinsic regulation of the parS/ParB/ParA system directly affects not only division site selection, but also cell growth. Other mechanisms, including the pole-organizing protein PopZ, compensate for the defect in segregation regulation in ΔtipN cells. Accordingly, synthetic lethality of PopZ and TipN is caused by severe chromosome segregation and cell division defects. Our data suggest a mechanistic framework for adapting a self-organizing oscillator to create motion suitable for chromosome segregation.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism*
  • Blotting, Western
  • Caulobacter crescentus / cytology*
  • Caulobacter crescentus / physiology
  • Cell Cycle / physiology*
  • Cell Polarity*
  • Chromosome Segregation*
  • Chromosomes, Bacterial / physiology*
  • Immunoprecipitation
  • Replication Origin

Substances

  • Bacterial Proteins
  • chromosome partition proteins, bacterial