title: Cell type-specific phosphorylation and proteolysis of a transcriptional regulator controls the G1-to-S transition in a bacterial cell cycle.
abstract: The global transcriptional regulator CtrA controls multiple events in the Caulobacter cell cycle, including the initiation of DNA replication, DNA methylation, cell division, and flagellar biogenesis. CtrA is a member of the response regulator family of two component signal transduction systems and is activated by phosphorylation. We report here that this phosphorylation signal enters the cell cycle at mid S phase. In addition, CtrA function is modulated by temporally and spatially controlled proteolysis. When an active CtrA protein is present at the wrong time in the cell cycle, owing to expression of a mutant CtrA derivative that is active in the absence of phosphorylation and is not turned over during the cell cycle, the G1-to-S transition is blocked and the cell cycle aborts. Thus, both phosphorylation and proteolysis are critical determinants of bacterial cell cycle control in a manner that is analogous to the control of the eukaryotic cell cycle.
authors.affiliation: Department of Developmental Biology, Stanford University School of Medicine, California 94305, USA.
authors.forename: I J
authors.initials: IJ
authors.lastname: Domian
authors.forename: K C
authors.initials: KC
authors.lastname: Quon
authors.forename: L
authors.initials: L
authors.lastname: Shapiro
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000378:metabolism*; D016934:Caulobacter / Q000166:cytology* / Q000378:metabolism*; D002453:Cell Cycle / Q000502:physiology*; D017931:DNA Primers; D004261:DNA Replication; D004268:DNA-Binding Proteins; D016193:G1 Phase; D006868:Hydrolysis; D016297:Mutagenesis, Site-Directed; D010766:Phosphorylation; D016133:Polymerase Chain Reaction; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000378:metabolism; D016196:S Phase; D017384:Sequence Deletion; D014157:Transcription Factors; D014158:Transcription, Genetic
chemical_list: D001426:Bacterial Proteins; C097706:CtrA protein, Caulobacter; D017931:DNA Primers; D004268:DNA-Binding Proteins; D011994:Recombinant Proteins; D014157:Transcription Factors