Disappearance of the sigma E transcription factor from the forespore and the SpoIIE phosphatase from the mother cell contributes to establishment of cell-specific gene expression during sporulation in Bacillus subtilis

J Bacteriol. 1997 May;179(10):3331-41. doi: 10.1128/jb.179.10.3331-3341.1997.

Abstract

We used immunofluorescence microscopy to investigate mechanisms governing the establishment of cell-specific gene transcription during sporulation in the bacterium Bacillus subtilis. The transcription factors sigma E and sigma F are synthesized shortly after the start of sporulation but do not become active in directing gene transcription until after polar division, when the activity of sigma E is confined to the mother cell and the activity of sigma F is restricted to the forespore. We show that shortly after septation, sigma E and its proprotein precursor pro-sigma E appear to be absent from the forespore and that a null mutation in spoIIIE, a gene known to be required for the translocation of a chromosome into the forespore, allows sigma E and/or pro-sigma E to persist and sigma E to become active in the forespore. These findings suggest that the loss of sigma E/pro-sigma E from the forespore contributes to the compartmentalization of sigma E-directed gene transcription. We also investigated the distribution of SpoIIE, a regulatory phosphatase required for the activation of sigma F which exhibits a bipolar pattern of localization shortly after the start of sporulation. Normally, SpoIIE rapidly disappears from the sporangium, first from the mother-cell pole and then from the forespore pole. Here we show that a null mutation in spoIIIE causes the SpoIIE phosphatase to persist at both poles. The persistence of the SpoIIE phosphatase at the mother-cell pole could explain the lack of compartmentalization of sigma F activity observed in a spoIIIE null mutant. We conclude that the establishment of cell-specific gene transcription involves the loss of sigma E/pro-sigma E from the forespore and the loss of the SpoIIE phosphatase from the mother-cell pole and that both processes are dependent upon the SpoIIIE protein.

Publication types

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

MeSH terms

  • Bacillus subtilis / enzymology
  • Bacillus subtilis / genetics
  • Bacillus subtilis / metabolism
  • Bacillus subtilis / physiology*
  • Bacterial Proteins / genetics*
  • Cell Compartmentation / genetics
  • Gene Expression Regulation, Bacterial / physiology*
  • Mutagenesis, Insertional
  • Phosphoprotein Phosphatases / genetics*
  • Phosphoprotein Phosphatases / metabolism
  • Sigma Factor / genetics*
  • Sigma Factor / physiology
  • Spores, Bacterial / enzymology
  • Spores, Bacterial / genetics
  • Transcription Factors / genetics*
  • Transcription Factors / physiology

Substances

  • Bacterial Proteins
  • Sigma Factor
  • Transcription Factors
  • spoIIR protein, Bacillus subtilis
  • spore-specific proteins, Bacillus
  • sporulation-specific sigma factors
  • Phosphoprotein Phosphatases