title: Cell pole-specific activation of a critical bacterial cell cycle kinase.
abstract: Caulobacter crescentus integrates phospho-signaling pathways and transcription factor regulatory cascades to drive the cell cycle. Despite the essential role of the CckA histidine kinase in the control of cell cycle events, the factors that signal its activation at a specific time in the cell cycle have remained elusive. A conditional genetic screen for CckA mislocalization mutants, using automated fluorescence microscopy and an image processing platform, revealed that the essential DivL protein kinase promotes CckA localization, autophosphorylation, and activity at the new cell pole. The transient accumulation of DivL at the new cell pole, but not its kinase activity, is required for the localization and activation of CckA. Because DivL and CckA accumulate at the same cell pole after the initiation of DNA replication and were found to interact in vivo, we propose that DivL recruits CckA to the pole, thereby promoting its autophosphorylation and activity.
authors.affiliation: Department of Developmental Biology, Beckman Center, Stanford University School of Medicine, Stanford, CA 94305, USA.
authors.forename: Antonio A
authors.initials: AA
authors.lastname: Iniesta
authors.forename: Nathan J
authors.initials: NJ
authors.lastname: Hillson
authors.forename: Lucy
authors.initials: L
authors.lastname: Shapiro
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism / Q000502:physiology; D016935:Caulobacter crescentus / Q000378:metabolism*; D002453:Cell Cycle / Q000502:physiology*; D016193:G1 Phase; D015964:Gene Expression Regulation, Bacterial; D017930:Genes, Reporter; D006420:Hemeproteins / Q000378:metabolism / Q000502:physiology; D000071677:Histidine Kinase; D008856:Microscopy, Fluorescence / Q000379:methods; D008954:Models, Biological; D010766:Phosphorylation; D011494:Protein Kinases / Q000378:metabolism / Q000502:physiology*; D015398:Signal Transduction
chemical_list: D001426:Bacterial Proteins; D006420:Hemeproteins; D011494:Protein Kinases; C067929:FixL protein, Bacteria; D000071677:Histidine Kinase