A dynamically localized protease complex and a polar specificity factor control a cell cycle master regulator

Cell. 2006 Feb 10;124(3):535-47. doi: 10.1016/j.cell.2005.12.033.

Abstract

Regulated proteolysis is essential for cell cycle progression in both prokaryotes and eukaryotes. We show here that the ClpXP protease, responsible for the degradation of multiple bacterial proteins, is dynamically localized to specific cellular positions in Caulobacter where it degrades colocalized proteins. The CtrA cell cycle master regulator, that must be cleared from the Caulobacter cell to allow the initiation of chromosome replication, interacts with the ClpXP protease at the cell pole where it is degraded. We have identified a novel, conserved protein, RcdA, that forms a complex with CtrA and ClpX in the cell. RcdA is required for CtrA polar localization and degradation by ClpXP. The localization pattern of RcdA is coincident with and dependent upon ClpX localization. Thus, a dynamically localized ClpXP proteolysis complex in concert with a cytoplasmic factor provides temporal and spatial specificity to protein degradation during a bacterial cell cycle.

Publication types

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

MeSH terms

  • Bacterial Proteins / chemistry
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism*
  • Caulobacter / cytology*
  • Caulobacter / genetics
  • Caulobacter / metabolism*
  • Cell Cycle / genetics
  • Cell Cycle / physiology
  • Cell Polarity
  • DNA-Binding Proteins / chemistry
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism*
  • Endopeptidase Clp / chemistry
  • Endopeptidase Clp / genetics
  • Endopeptidase Clp / metabolism*
  • Genes, Bacterial
  • Multiprotein Complexes
  • Recombinant Fusion Proteins / chemistry
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / metabolism
  • Transcription Factors / chemistry
  • Transcription Factors / genetics
  • Transcription Factors / metabolism*

Substances

  • Bacterial Proteins
  • CtrA protein, Caulobacter
  • DNA-Binding Proteins
  • Multiprotein Complexes
  • Recombinant Fusion Proteins
  • Transcription Factors
  • Endopeptidase Clp