TY - JOUR
T1 - A three-protein inhibitor of polar septation during sporulation in Bacillus subtilis
AU - Eichenberger, Patrick
AU - Fawcett, Paul
AU - Losick, Richard
N1 - Copyright:
Copyright 2008 Elsevier B.V., All rights reserved.
PY - 2001
Y1 - 2001
N2 - We present evidence for a three-protein inhibitor of polar division that locks in asymmetry after the formation of a polar septum during sporulation in Bacillus subtilis. Asymmetric division involves the formation of cytokinetic Z-rings near both poles of the developing cell. Next, a septum is formed at one of the two polar Z-rings, thereby generating a small, forespore cell and a mother cell. Gene expression under the control of the mother-cell transcription factor σE is needed to block cytokinesis at the pole distal to the newly formed septum. We report that this block in polar cytokinesis is mediated partly by σE-directed transcription of spoIID, spoIIM and spoIIP, sporulation genes that were known to be involved in the subsequent process of forespore engulfment. We find that a spoIID, spoIIM and spoIIP triple mutant substantially mimicked the bipolar division phenotype of a σE mutant and that cells engineered to produce SpoIID, SpoIIM and SpoIIP prematurely were inhibited in septum formation at both poles. Consistent with the hypothesis that SpoIID, SpoIIM and SpoIIP function at both poles of the sporangium, a GFP-SpoIIM fusion localized to the membrane that surrounds the engulfed forespore and to the potential division site at the distal pole.
AB - We present evidence for a three-protein inhibitor of polar division that locks in asymmetry after the formation of a polar septum during sporulation in Bacillus subtilis. Asymmetric division involves the formation of cytokinetic Z-rings near both poles of the developing cell. Next, a septum is formed at one of the two polar Z-rings, thereby generating a small, forespore cell and a mother cell. Gene expression under the control of the mother-cell transcription factor σE is needed to block cytokinesis at the pole distal to the newly formed septum. We report that this block in polar cytokinesis is mediated partly by σE-directed transcription of spoIID, spoIIM and spoIIP, sporulation genes that were known to be involved in the subsequent process of forespore engulfment. We find that a spoIID, spoIIM and spoIIP triple mutant substantially mimicked the bipolar division phenotype of a σE mutant and that cells engineered to produce SpoIID, SpoIIM and SpoIIP prematurely were inhibited in septum formation at both poles. Consistent with the hypothesis that SpoIID, SpoIIM and SpoIIP function at both poles of the sporangium, a GFP-SpoIIM fusion localized to the membrane that surrounds the engulfed forespore and to the potential division site at the distal pole.
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U2 - 10.1046/j.1365-2958.2001.02660.x
DO - 10.1046/j.1365-2958.2001.02660.x
M3 - Article
C2 - 11886548
AN - SCOPUS:0035725455
SN - 0950-382X
VL - 42
SP - 1147
EP - 1162
JO - Molecular Microbiology
JF - Molecular Microbiology
IS - 5
ER -