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Positioning of chemosensory proteins and FtsZ through the R hodobacter sphaeroides cell cycle
Author(s) -
Chiu ShengWen,
Roberts Mark A. J.,
Leake Mark C.,
Armitage Judith P.
Publication year - 2013
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/mmi.12366
Subject(s) - ftsz , mreb , cytokinesis , cell division , biology , cytoskeleton , microbiology and biotechnology , cytoplasm , cell , genetics
Summary Bacterial chemotaxis depends on signalling through large protein complexes. Each cell must inherit a complex on division, suggesting some co‐ordination with cell division. In E scherichia coli the membrane‐spanning chemosensory complexes are polar and new static complexes form at pre‐cytokinetic sites, ensuring positioning at the new pole after division and suggesting a role for the bacterial cytoskeleton. R hodobacter sphaeroides has both membrane‐associated and cytoplasmic, chromosome‐associated chemosensory complexes. We followed the relative positions of the two chemosensory complexes, FtsZ and MreB in aerobic and in photoheterotrophic R . sphaeroides cells using fluorescence microscopy. FtsZ forms polar spots after cytokinesis, which redistribute to the midcell forming nodes from which FtsZ extends circumferentially to form the Z ‐ring. Membrane‐associated chemosensory proteins form a number of dynamic unit‐clusters with mature clusters containing about 1000 CheW 3 proteins. Individual clusters diffuse randomly within the membrane, accumulating at new poles after division but not colocalizing with either FtsZ or MreB . The cytoplasmic complex colocalizes with FtsZ at midcells in new‐born cells. Before cytokinesis one complex moves to a daughter cell, followed by the second moving to the other cell. These data indicate that two homologous complexes use different mechanisms to ensure partitioning, and neither complex utilizes FtsZ or MreB for positioning.