title: Cell cycle transition from S-phase to G1 in Caulobacter is mediated by ancestral virulence regulators.
abstract: Zinc-finger domain transcriptional regulators regulate a myriad of functions in eukaryotes. Interestingly, ancestral versions (MucR) from Alpha-proteobacteria control bacterial virulence/symbiosis. Whether virulence regulators can also control cell cycle transcription is unknown. Here we report that MucR proteins implement a hitherto elusive primordial S→G1 transcriptional switch. After charting G1-specific promoters in the cell cycle model Caulobacter crescentus by comparative ChIP-seq, we use one such promoter as genetic proxy to unearth two MucR paralogs, MucR1/2, as constituents of a quadripartite and homeostatic regulatory module directing the S→G1 transcriptional switch. Surprisingly, MucR orthologues that regulate virulence and symbiosis gene transcription in Brucella, Agrobacterium or Sinorhizobium support this S→G1 switch in Caulobacter. Pan-genomic ChIP-seq analyses in Sinorhizobium and Caulobacter show that this module indeed targets orthologous genes. We propose that MucR proteins and possibly other virulence regulators primarily control bacterial cell cycle (G1-phase) transcription, rendering expression of target (virulence) genes periodic and in tune with the cell cycle.
authors.affiliation: Department Microbiology and Molecular Medicine, Faculty of Medicine/CMU, Institute of Genetics and Genomics in Geneva (iGE3), University of Geneva, Rue Michel Servet 1, 1211 Genève 4, Switzerland.
authors.forename: Coralie
authors.initials: C
authors.lastname: Fumeaux
authors.affiliation: 1] Department Microbiology and Molecular Medicine, Faculty of Medicine/CMU, Institute of Genetics and Genomics in Geneva (iGE3), University of Geneva, Rue Michel Servet 1, 1211 Genève 4, Switzerland [2].
authors.forename: Sunish Kumar
authors.initials: SK
authors.lastname: Radhakrishnan
authors.affiliation: Department Microbiology and Molecular Medicine, Faculty of Medicine/CMU, Institute of Genetics and Genomics in Geneva (iGE3), University of Geneva, Rue Michel Servet 1, 1211 Genève 4, Switzerland.
authors.forename: Silvia
authors.initials: S
authors.lastname: Ardissone
authors.affiliation: Department Microbiology and Molecular Medicine, Faculty of Medicine/CMU, Institute of Genetics and Genomics in Geneva (iGE3), University of Geneva, Rue Michel Servet 1, 1211 Genève 4, Switzerland.
authors.forename: Laurence
authors.initials: L
authors.lastname: Théraulaz
authors.affiliation: Department Microbiology and Molecular Medicine, Faculty of Medicine/CMU, Institute of Genetics and Genomics in Geneva (iGE3), University of Geneva, Rue Michel Servet 1, 1211 Genève 4, Switzerland.
authors.forename: Antonio
authors.initials: A
authors.lastname: Frandi
authors.affiliation: Department Microbiology and Molecular Medicine, Faculty of Medicine/CMU, Institute of Genetics and Genomics in Geneva (iGE3), University of Geneva, Rue Michel Servet 1, 1211 Genève 4, Switzerland.
authors.forename: Daniel
authors.initials: D
authors.lastname: Martins
authors.affiliation: Biozentrum of the University of Basel, Klingelbergstrasse 50/70, 4056 Basel, Switzerland.
authors.forename: Jutta
authors.initials: J
authors.lastname: Nesper
authors.affiliation: 1] Biozentrum of the University of Basel, Klingelbergstrasse 50/70, 4056 Basel, Switzerland [2].
authors.forename: Sören
authors.initials: S
authors.lastname: Abel
authors.affiliation: Biozentrum of the University of Basel, Klingelbergstrasse 50/70, 4056 Basel, Switzerland.
authors.forename: Urs
authors.initials: U
authors.lastname: Jenal
authors.affiliation: Department Microbiology and Molecular Medicine, Faculty of Medicine/CMU, Institute of Genetics and Genomics in Geneva (iGE3), University of Geneva, Rue Michel Servet 1, 1211 Genève 4, Switzerland.
authors.forename: Patrick H
authors.initials: PH
authors.lastname: Viollier
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D016934:Caulobacter / Q000502:physiology*; D047369:Chromatin Immunoprecipitation; D019281:Dimerization; D024202:Electrophoretic Mobility Shift Assay; D016193:G1 Phase / Q000235:genetics / Q000502:physiology*; D015964:Gene Expression Regulation, Bacterial / Q000235:genetics / Q000502:physiology*; D015151:Immunoblotting; D008954:Models, Biological; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*; D059807:S Phase Cell Cycle Checkpoints / Q000235:genetics / Q000502:physiology*; D017422:Sequence Analysis, DNA; D013045:Species Specificity; D001616:beta-Galactosidase
chemical_list: D001426:Bacterial Proteins; D012097:Repressor Proteins; D001616:beta-Galactosidase