title: General protein diffusion barriers create compartments within bacterial cells.
abstract: In eukaryotes, the differentiation of cellular extensions such as cilia or neuronal axons depends on the partitioning of proteins to distinct plasma membrane domains by specialized diffusion barriers. However, examples of this compartmentalization strategy are still missing for prokaryotes, although complex cellular architectures are also widespread among this group of organisms. This study reveals the existence of a protein-mediated membrane diffusion barrier in the stalked bacterium Caulobacter crescentus. We show that the Caulobacter cell envelope is compartmentalized by macromolecular complexes that prevent the exchange of both membrane and soluble proteins between the polar stalk extension and the cell body. The barrier structures span the cross-sectional area of the stalk and comprise at least four proteins that assemble in a cell-cycle-dependent manner. Their presence is critical for cellular fitness because they minimize the effective cell volume, allowing faster adaptation to environmental changes that require de novo synthesis of envelope proteins.
authors.affiliation: Max Planck Research Group Prokaryotic Cell Biology, Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch-Strasse 10, 35043 Marburg, Germany.
authors.forename: Susan
authors.initials: S
authors.lastname: Schlimpert
authors.forename: Eric A
authors.initials: EA
authors.lastname: Klein
authors.forename: Ariane
authors.initials: A
authors.lastname: Briegel
authors.forename: Velocity
authors.initials: V
authors.lastname: Hughes
authors.forename: Jörg
authors.initials: J
authors.lastname: Kahnt
authors.forename: Kathrin
authors.initials: K
authors.lastname: Bolte
authors.forename: Uwe G
authors.initials: UG
authors.lastname: Maier
authors.forename: Yves V
authors.initials: YV
authors.lastname: Brun
authors.forename: Grant J
authors.initials: GJ
authors.lastname: Jensen
authors.forename: Zemer
authors.initials: Z
authors.lastname: Gitai
authors.forename: Martin
authors.initials: M
authors.lastname: Thanbichler
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism*; D016935:Caulobacter crescentus / Q000166:cytology* / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D004058:Diffusion; D046912:Multiprotein Complexes / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D046912:Multiprotein Complexes