J Bacteriol, April 1998, p. 1673-1681, Vol. 180, No. 7
0021-9193/98/$04.00+0
Copyright © 1998, American Society for Microbiology. All rights reserved.
Department of Microbiology, University of Texas Health Science Center at San Antonio, San Antonio, Texas 78284-7758
Received 14 October 1997/Accepted 2 February 1998
E is a mother cell-specific transcription factor of
sporulating Bacillus subtilis that is derived from an
inactive precursor protein (pro-
E). To examine the
process that prevents
E activity from developing in the
forespore, we fused the
E structural gene
(sigE) to forespore-specific promoters
(PdacF and PspoIIIG),
placed these fusions at sites on the B. subtilis chromosome
which translocate into the forespore either early or late, and used
Western blot analysis to monitor SigE accumulation and
pro-
E processing. sigE alleles, placed at
sites which entered the forespore early, were found to generate more
protein product than the same fusion placed at a late entering site.
SigE accumulation and processing in the forespore were enhanced by null
mutations in spoIIIE, a gene whose product is essential for
translocation of the distal portion of the B. subtilis
chromosome into the forespore. In other experiments, a chimera of
pro-
E and green fluorescence protein, previously shown
to be unprocessed if it is synthesized within the forespore, was found
to be processed in this compartment if coexpressed with the gene for
the pro-
E-processing enzyme, SpoIIGA. The need for
spoIIGA coexpression is obviated in the absence of SpoIIIE.
We interpret these results as evidence that selective degradation of
both SigE and SpoIIGA prevent mature
E from accumulating
in the forespore compartment of wild-type B. subtilis.
Presumably, a gene(s) located at a site that is distal to the origin of
chromosome transfer is responsible for this phenomenon when it is
translocated and expressed in the forespore.
This article has been cited by other articles:
| Appl. Environ. Microbiol. | Infect. Immun. | Eukaryot. Cell |
|---|---|---|
| Mol. Cell. Biol. | J. Virol. | Microbiol. Mol. Biol. Rev. |
| ALL ASM JOURNALS |