Regulated intramembrane proteolysis of FtsL protein and the control of cell division in Bacillus subtilis

Mol Microbiol. 2006 Oct;62(2):580-91. doi: 10.1111/j.1365-2958.2006.05402.x.

Abstract

The small bitopic division protein FtsL is an essential part of the division machinery (divisome) in most eubacteria. In Bacillus subtilis FtsL is a highly unstable protein and the turnover has been implicated in regulation of division in response to DNA damage. N-terminal deletions and a domain swap experiment identified the short cytoplasmic domain of FtsL as being required for instability. We then identified a zinc metalloprotease, YluC, required for turnover, and likely sequence motifs involved in substrate recognition. YluC belongs to the site-2-protease (S2P) family of proteases involved in regulated intramembrane proteolysis (RIP), which plays a role in diverse regulatory phenomena from bacteria to man. The yluC mutant, and strains with N-terminal truncations of ftsL have a short cell phenotype, indicating that that FtsL is normally rate-limiting for division. Coexpression experiments of FtsL and YluC in Escherichia coli corroborated a model in which FtsL is directly cleaved by the membrane metalloprotease. The results shed new light on the regulation of cell division in B. subtilis and identify a novel class of targets for RIP.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Bacillus subtilis / cytology
  • Bacillus subtilis / genetics
  • Bacillus subtilis / metabolism*
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism*
  • Bacterial Proteins / physiology
  • Cell Division / genetics
  • Cell Division / physiology
  • Cytoplasm / metabolism
  • Escherichia coli / genetics
  • Immunoblotting
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism*
  • Membrane Proteins / physiology
  • Metalloproteases / metabolism
  • Microscopy, Confocal
  • Microscopy, Fluorescence
  • Molecular Sequence Data
  • Mutation / genetics
  • Recombinant Proteins / metabolism
  • Sequence Homology, Amino Acid

Substances

  • Bacterial Proteins
  • Membrane Proteins
  • Recombinant Proteins
  • Metalloproteases