title: Two small GTPases act in concert with the bactofilin cytoskeleton to regulate dynamic bacterial cell polarity.
abstract: Cell polarity is essential for many bacterial activities, but the mechanisms responsible for its establishment are poorly understood. In Myxococcus xanthus, the type IV pili (T4P) motor ATPases PilB and PilT localize to opposite cell poles and switch poles during cellular reversals. We demonstrate that polar localization of PilB and PilT depends on the small GTPase SofG and BacP, a bactofilin cytoskeletal protein. Polymeric BacP localizes in both subpolar regions. SofG interacts directly with polymeric BacP and associates with one of these patches, forming a cluster that shuttles to the pole to establish localization of PilB and PilT at the same pole. Next, the small GTPase MglA sorts PilB and PilT to opposite poles to establish their correct polarity. During reversals, the Frz chemosensory system induces the inversion of PilB and PilT polarity. Thus, three hierarchically organized systems function in a cascade to regulate dynamic bacterial cell polarity.
authors.affiliation: Max Planck Institute for Terrestrial Microbiology, Marburg 35043, Germany.
authors.forename: Iryna
authors.initials: I
authors.lastname: Bulyha
authors.forename: Steffi
authors.initials: S
authors.lastname: Lindow
authors.forename: Lin
authors.initials: L
authors.lastname: Lin
authors.forename: Kathrin
authors.initials: K
authors.lastname: Bolte
authors.forename: Kristin
authors.initials: K
authors.lastname: Wuichet
authors.forename: Jörg
authors.initials: J
authors.lastname: Kahnt
authors.forename: Chris
authors.initials: C
authors.lastname: van der Does
authors.forename: Martin
authors.initials: M
authors.lastname: Thanbichler
authors.forename: Lotte
authors.initials: L
authors.lastname: Søgaard-Andersen
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism; D015153:Blotting, Western; D002465:Cell Movement; D016764:Cell Polarity; D049109:Cell Proliferation; D003598:Cytoskeletal Proteins / Q000378:metabolism*; D003599:Cytoskeleton / Q000378:metabolism*; D010861:Fimbriae, Bacterial / Q000378:metabolism*; D047468:Immunoprecipitation; D008870:Microtubules / Q000378:metabolism; D020409:Molecular Motor Proteins / Q000378:metabolism; D020559:Monomeric GTP-Binding Proteins / Q000378:metabolism*; D016941:Myxococcus xanthus / Q000502:physiology*; D021381:Protein Transport
chemical_list: D001426:Bacterial Proteins; D003598:Cytoskeletal Proteins; D020409:Molecular Motor Proteins; D020559:Monomeric GTP-Binding Proteins