title: Identification of a localization factor for the polar positioning of bacterial structural and regulatory proteins.
abstract: Polar pili biogenesis in Caulobacter involves the asymmetric localization of the CpaE and CpaC components of the pili-specific secretion apparatus to one pole of the predivisional cell followed by the biosynthesis of the pili filaments in the daughter swarmer cell. The histidine kinase signaling protein, PleC, that controls the temporal accumulation of the PilA pilin subunit is asymmetrically localized to the pole at which pili are assembled. Here we identify a protein, PodJ, that provides the positional information for the polar localization of both PleC and CpaE. The PodJ protein was found to exist in two forms, a truncated 90-kDa and a full-length 110-kDa form, each controlling a different aspect of polar development and each localizing to the cell poles at a specific time in the cell cycle. When active PleC is delocalized in a DeltapodJ mutant, the accumulation of PilA, the downstream target of PleC signaling, is impaired, providing evidence that the polar localization of this histidine kinase stimulates the response signaled by a two-component system.
authors.affiliation: Department of Developmental Biology, Beckman Center B351, Stanford University School of Medicine, 279 Campus Drive, Palo Alto, CA 94304-5329, USA.
authors.forename: Patrick H
authors.initials: PH
authors.lastname: Viollier
authors.forename: Nitzan
authors.initials: N
authors.lastname: Sternheim
authors.forename: Lucy
authors.initials: L
authors.lastname: Shapiro
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D016935:Caulobacter crescentus / Q000166:cytology / Q000235:genetics / Q000378:metabolism*; D002453:Cell Cycle; D016764:Cell Polarity; D004268:DNA-Binding Proteins / Q000378:metabolism; D036781:Fimbriae Proteins; D010861:Fimbriae, Bacterial / Q000378:metabolism; D005798:Genes, Bacterial; D000071677:Histidine Kinase; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation; D011494:Protein Kinases / Q000378:metabolism; D015398:Signal Transduction
chemical_list: D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D008565:Membrane Proteins; C120058:podj protein, Caulobacter crescentus; D036781:Fimbriae Proteins; D011494:Protein Kinases; D000071677:Histidine Kinase