title: Poles apart: prokaryotic polar organelles and their spatial regulation.
abstract: While polar organelles hold the key to understanding the fundamentals of cell polarity and cell biological principles in general, they have served in the past merely for taxonomical purposes. Here, we highlight recent efforts in unraveling the molecular basis of polar organelle positioning in bacterial cells. Specifically, we detail the role of members of the Ras-like GTPase superfamily and coiled-coil-rich scaffolding proteins in modulating bacterial cell polarity and in recruiting effector proteins to polar sites. Such roles are well established for eukaryotic cells, but not for bacterial cells that are generally considered diffusion-limited. Studies on spatial regulation of protein positioning in bacterial cells, though still in their infancy, will undoubtedly experience a surge of interest, as comprehensive localization screens have yielded an extensive list of (polarly) localized proteins, potentially reflecting subcellular sites of functional specialization predicted for organelles.
authors.affiliation: Department of Microbiology and Molecular Medicine, Centre Médicale Universitaire, Faculty of Medicine, University of Geneva, Switzerland.
authors.forename: Clare L
authors.initials: CL
authors.lastname: Kirkpatrick
authors.forename: Patrick H
authors.initials: PH
authors.lastname: Viollier
mesh_terms: D001426:Bacterial Proteins / Q000502:physiology*; D002465:Cell Movement / Q000502:physiology*; D016764:Cell Polarity / Q000502:physiology*; D010861:Fimbriae, Bacterial / Q000502:physiology; D020409:Molecular Motor Proteins / Q000378:metabolism*; D015388:Organelles / Q000502:physiology* / Q000648:ultrastructure; D011134:Polysaccharides / Q000378:metabolism; D011387:Prokaryotic Cells / Q000166:cytology*; D018631:ras Proteins / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D020409:Molecular Motor Proteins; D011134:Polysaccharides; D018631:ras Proteins