Lipid-linked cell wall precursors regulate membrane association of bacterial actin MreB.
The bacterial actin homolog MreB, which is crucial for rod shape determination, forms filaments that rotate around the cell width on the inner surface of the cytoplasmic membrane. What determines filament association with the membranes or with other cell wall elongation proteins is not known. Using specific chemical and genetic perturbations while following MreB filament motion, we find that MreB membrane association is an actively regulated process that depends on the presence of lipid-linked peptidoglycan precursors. When precursors are depleted, MreB filaments disassemble into the cytoplasm, and peptidoglycan synthesis becomes disorganized. In cells that lack wall teichoic acids but continue to make peptidoglycan, dynamic MreB filaments are observed, although their presence is not sufficient to establish a rod shape. We propose that the cell regulates MreB filament association with the membrane, allowing rapid and reversible inactivation of cell wall enzyme complexes in response to the inhibition of cell wall synthesis.
Department of Microbiology and Immunobiology, Harvard Medical School, Boston, Massachusetts, USA.
Kathrin
K
Schirner
Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts, USA.
Ye-Jin
YJ
Eun
Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts, USA.
Mike
M
Dion
Department of Microbiology, Cornell University, Ithaca, New York, USA.
Yun
Y
Luo
Department of Microbiology, Cornell University, Ithaca, New York, USA.
John D
JD
Helmann
Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts, USA.
Ethan C
0000000301413555
EC
Garner
Department of Microbiology and Immunobiology, Harvard Medical School, Boston, Massachusetts, USA.
Suzanne
S
Walker
D019883:Alkyl and Aryl Transferases / Q000378:metabolism; D001412:Bacillus subtilis / Q000235:genetics / Q000378:metabolism; D001419:Bacteria / Q000378:metabolism* / Q000648:ultrastructure; D002462:Cell Membrane / Q000378:metabolism; D002473:Cell Wall / Q000378:metabolism*; D003593:Cytoplasm / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000502:physiology*; D006017:Glycolipids / Q000378:metabolism; D011498:Protein Precursors / Q000502:physiology*; D013682:Teichoic Acids / Q000378:metabolism
D029968:Escherichia coli Proteins; D006017:Glycolipids; D011498:Protein Precursors; D013682:Teichoic Acids; C078473:MreB protein, E coli; D019883:Alkyl and Aryl Transferases; C023266:undecaprenyl pyrophosphate synthetase