title: Bacillus subtilis MreB orthologs self-organize into filamentous structures underneath the cell membrane in a heterologous cell system.
abstract: Actin-like bacterial cytoskeletal element MreB has been shown to be essential for the maintenance of rod cell shape in many bacteria. MreB forms rapidly remodelling helical filaments underneath the cell membrane in Bacillus subtilis and in other bacterial cells, and co-localizes with its two paralogs, Mbl and MreBH. We show that MreB localizes as dynamic bundles of filaments underneath the cell membrane in Drosophila S2 Schneider cells, which become highly stable when the ATPase motif in MreB is modified. In agreement with ATP-dependent filament formation, the depletion of ATP in the cells lead to rapid dissociation of MreB filaments. Extended induction of MreB resulted in the formation of membrane protrusions, showing that like actin, MreB can exert force against the cell membrane. Mbl also formed membrane associated filaments, while MreBH formed filaments within the cytosol. When co-expressed, MreB, Mbl and MreBH built up mixed filaments underneath the cell membrane. Membrane protein RodZ localized to endosomes in S2 cells, but localized to the cell membrane when co-expressed with Mbl, showing that bacterial MreB/Mbl structures can recruit a protein to the cell membrane. Thus, MreB paralogs form a self-organizing and dynamic filamentous scaffold underneath the membrane that is able to recruit other proteins to the cell surface.
authors: Mikrobiologie, Fakultät für Biologie, Universität Freiburg, Freiburg, Germany.
authors: Felix
authors: F
authors: Dempwolff
authors: Christian
authors: C
authors: Reimold
authors: Michael
authors: M
authors: Reth
authors: Peter L
authors: PL
authors: Graumann
mesh_terms: D008841:Actin Cytoskeleton / Q000378:metabolism*; D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D001412:Bacillus subtilis / Q000254:growth & development / Q000378:metabolism*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism*; D002478:Cells, Cultured; D003598:Cytoskeletal Proteins / Q000235:genetics / Q000378:metabolism; D017931:DNA Primers / Q000737:chemistry; D004331:Drosophila melanogaster / Q000254:growth & development / Q000378:metabolism*; D005455:Fluorescent Antibody Technique; D015964:Gene Expression Regulation, Bacterial; D008565:Membrane Proteins / Q000378:metabolism*; D009154:Mutation / Q000235:genetics; D010957:Plasmids
chemical_list: D001426:Bacterial Proteins; D003598:Cytoskeletal Proteins; D017931:DNA Primers; D008565:Membrane Proteins; C424044:mbl protein, Bacillus subtilis; D000255:Adenosine Triphosphate