The "pro" sequence of the sporulation-specific sigma transcription factor sigma(E) directs it to the mother cell side of the sporulation septum

J Bacteriol. 1999 Oct;181(19):6171-5. doi: 10.1128/JB.181.19.6171-6175.1999.

Abstract

sigma(E), a mother cell-specific transcription factor of sporulating Bacillus subtilis, is derived from an inactive precursor protein (pro-sigma(E)). Activation of sigma(E) occurs when a sporulation-specific protease (SpoIIGA) cleaves 27 amino acids from the pro-sigma(E) amino terminus. This reaction is believed to take place at the mother cell-forespore septum. Using a chimera of pro-sigma(E) and green fluorescent protein (GFP) to visualize the intracellular location of pro-sigma(E) by fluorescence microscopy, and lysozyme treatment to separate the mother cell and forespore compartments, we determined that the pro-sigma(E)::GFP signal, localized to the forespore septum prior to lysozyme treatment, is restricted to the mother cell compartment after treatment. Thus, pro-sigma(E)::GFP had been sequestered to the mother cell side of the septum. This segregation of pro-sigma(E)::GFP, and presumably pro-sigma(E), to the mother cell is likely to be the reason why sigma(E) activity is restricted to that compartment.

Publication types

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

MeSH terms

  • Bacillus subtilis / physiology*
  • Bacterial Proteins / metabolism
  • Biological Transport
  • Cell Compartmentation
  • Endopeptidases / metabolism
  • Green Fluorescent Proteins
  • Luminescent Proteins / genetics
  • Luminescent Proteins / metabolism
  • Membrane Proteins / metabolism
  • Peptide Hydrolases*
  • Protein Precursors / metabolism*
  • Protein Processing, Post-Translational
  • Protein Sorting Signals / metabolism*
  • Recombinant Fusion Proteins / metabolism
  • Sigma Factor / genetics
  • Sigma Factor / metabolism*
  • Spores, Bacterial
  • Transcription Factors / genetics
  • Transcription Factors / metabolism*

Substances

  • Bacterial Proteins
  • Luminescent Proteins
  • Membrane Proteins
  • Protein Precursors
  • Protein Sorting Signals
  • Recombinant Fusion Proteins
  • Sigma Factor
  • Transcription Factors
  • pro-sigmaE protein, Bacillus subtilis
  • Green Fluorescent Proteins
  • Endopeptidases
  • Peptide Hydrolases
  • SpoIIGA protein, Bacillus subtilis