title: Actin homolog MreBH governs cell morphogenesis by localization of the cell wall hydrolase LytE.
abstract: MreB proteins are bacterial actin homologs involved in cell morphogenesis and various other cellular processes. However, the effector proteins used by MreBs remain largely unknown. Bacillus subtilis has three MreB isoforms. Mbl and possibly MreB have previously been shown to be implicated in cell wall synthesis. We have now found that the third isoform, MreBH, colocalizes with the two other MreB isoforms in B. subtilis and also has an important role in cell morphogenesis. MreBH can physically interact with a cell wall hydrolase, LytE, and is required for its helical pattern of extracellular localization. Moreover, lytE and mreBH mutants exhibit similar cell-wall-related defects. We propose that controlled elongation of rod-shaped B. subtilis depends on the coordination of cell wall synthesis and hydrolysis in helical tracts defined by MreB proteins. Our data also suggest that physical interactions with intracellular actin bundles can influence the later localization pattern of extracellular effectors.
authors.affiliation: Génétique Microbienne, Institut National de la Recherche Agronomique, 78352 Jouy-en-Josas Cedex, France. rut.caballido-lopez@jouy.inra.fr
authors.forename: Rut
authors.initials: R
authors.lastname: Carballido-López
authors.forename: Alex
authors.initials: A
authors.lastname: Formstone
authors.forename: Ying
authors.initials: Y
authors.lastname: Li
authors.forename: S Dusko
authors.initials: SD
authors.lastname: Ehrlich
authors.forename: Philippe
authors.initials: P
authors.lastname: Noirot
authors.forename: Jeff
authors.initials: J
authors.lastname: Errington
mesh_terms: D000199:Actins / Q000032:analysis / Q000378:metabolism* / Q000502:physiology*; D001412:Bacillus subtilis / Q000201:enzymology / Q000235:genetics / Q000254:growth & development*; D001426:Bacterial Proteins / Q000378:metabolism / Q000502:physiology*; D016764:Cell Polarity; D002473:Cell Wall / Q000378:metabolism* / Q000502:physiology; D020090:Chromosome Segregation; D002876:Chromosomes, Bacterial; D006867:Hydrolases / Q000378:metabolism*; D008274:Magnesium / Q000494:pharmacology; D008954:Models, Biological; D009024:Morphogenesis; D009238:N-Acetylmuramoyl-L-alanine Amidase / Q000378:metabolism / Q000502:physiology*
chemical_list: D000199:Actins; D001426:Bacterial Proteins; D006867:Hydrolases; C112181:LytE protein, Bacillus subtilis; D009238:N-Acetylmuramoyl-L-alanine Amidase; D008274:Magnesium