EzrA prevents aberrant cell division by modulating assembly of the cytoskeletal protein FtsZ.
In response to a cell cycle signal, the cytoskeletal protein FtsZ assembles into a ring structure that establishes the location of the division site and serves as a framework for assembly of the division machinery. A battery of factors control FtsZ assembly to ensure that the ring forms in the correct position and at the precise time. EzrA, a negative regulator of FtsZ ring formation, is important for ensuring that the ring forms only once per cell cycle and that cytokinesis is restricted to mid-cell. EzrA is distributed throughout the plasma membrane and localizes to the ring in an FtsZ-dependent manner, suggesting that it interacts directly with FtsZ to modulate assembly. We have performed a series of experiments examining the interaction between EzrA and FtsZ. As little as twofold overexpression of EzrA blocks FtsZ ring formation in a sensitized genetic background, consistent with its predicted function. A purified EzrA fusion protein interacts directly with FtsZ to block assembly in vitro. Although EzrA is able to inhibit FtsZ assembly, it is unable to disassemble preformed polymers. These data support a model in which EzrA interacts directly with FtsZ at the plasma membrane to prevent polymerization and aberrant FtsZ ring formation.
Haeusser
Daniel P
DP
Department of Biology, Box 1137, Washington University, One Brookings Drive, St Louis, MO 63130, USA.
Schwartz
Rachel L
RL
Smith
Alison M
AM
Oates
Michelle Erin
ME
Levin
Petra Anne
PA
D001412:Bacillus subtilis / Q000378:metabolism / Q000648:ultrastructure; D001426:Bacterial Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D002455:Cell Division / Q000502:physiology*; D002462:Cell Membrane / Q000378:metabolism; D003598:Cytoskeletal Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D006153:Guanosine Diphosphate / Q000378:metabolism; D006160:Guanosine Triphosphate / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D013879:Thioredoxins / Q000378:metabolism
D001426:Bacterial Proteins; D003598:Cytoskeletal Proteins; C121014:EzrA protein, Bacillus subtilis; C071525:FtsZ protein, Bacteria; D011993:Recombinant Fusion Proteins; D006153:Guanosine Diphosphate; D013879:Thioredoxins; D006160:Guanosine Triphosphate