Identification and Transcriptional Control of the Genes Encoding the
            <i>Caulobacter crescentus</i>
            ClpXP Protease

Østerås, Magne; Stotz, Agathe; Nuoffer, Stefanie Schmid; Jenal, Urs

doi:10.1128/jb.181.10.3039-3050.1999

Cited by 34 publications

(19 citation statements)

References 54 publications

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“…Fifty seven of these CDSs containing multiple promoters are essential for viability [22] . In Caulobacter , only 18 cell cycle-regulated genes, including ctrA , dnaN , clpX , and rcdA , have been shown previously to be transcribed from multiple cell cycle controlled promoters using either tiling microarrays, nuclease protection, or primer extension assays [25] , [32] , [48] , [49] . We found that 102 CDSs (42% of those with multiple upstream TSSs) have at least one cell cycle-regulated TSS, and 25 CDSs, including ctrA (3 promoters, Fig.…”

Section: Resultsmentioning

confidence: 99%

The Global Regulatory Architecture of Transcription during the Caulobacter Cell Cycle

et al. 2015

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Each Caulobacter cell cycle involves differentiation and an asymmetric cell division driven by a cyclical regulatory circuit comprised of four transcription factors (TFs) and a DNA methyltransferase. Using a modified global 5′ RACE protocol, we globally mapped transcription start sites (TSSs) at base-pair resolution, measured their transcription levels at multiple times in the cell cycle, and identified their transcription factor binding sites. Out of 2726 TSSs, 586 were shown to be cell cycle-regulated and we identified 529 binding sites for the cell cycle master regulators. Twenty-three percent of the cell cycle-regulated promoters were found to be under the combinatorial control of two or more of the global regulators. Previously unknown features of the core cell cycle circuit were identified, including 107 antisense TSSs which exhibit cell cycle-control, and 241 genes with multiple TSSs whose transcription levels often exhibited different cell cycle timing. Cumulatively, this study uncovered novel new layers of transcriptional regulation mediating the bacterial cell cycle.

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Section: Resultsmentioning

confidence: 99%

The Global Regulatory Architecture of Transcription during the Caulobacter Cell Cycle

et al. 2015

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“…In contrast, C. crescentus has a different arrangement (Fig. S2B), with CicA (42) being encoded by a sequence between clpP and clpX and transcribed in the opposite direction (43). C. crescentus clpX is transcribed independently of clpP from its own set of promoters (43), whereas in E. coli, clpX appears to be expressed predominantly from the clpP promoter, with a weak promoter being present between clpP and clpX (41).…”

Section: Resultsmentioning

confidence: 99%

“…3A). No Rho-independent transcriptional terminator was predicted between clpP and clpX in R. capsulatus (using the tool ARNold [data not shown]), unlike in C. crescentus (43).…”

Section: Resultsmentioning

confidence: 99%

The Protease ClpXP and the PAS Domain Protein DivL Regulate CtrA and Gene Transfer Agent Production in Rhodobacter capsulatus

Westbye

Kater

Wiesmann

et al. 2018

Appl Environ Microbiol

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Several members of the () produce a conserved horizontal gene transfer vector, called the gene transfer agent (GTA), that appears to have evolved from a bacteriophage. The model system used to study GTA biology is the GTA (RcGTA), a small, tailed bacteriophage-like particle produced by a subset of the cells in a culture. The response regulator CtrA is conserved in the and is an essential regulator of RcGTA production: it controls the production and maturation of the RcGTA particle and RcGTA release from cells. CtrA also controls the natural transformation-like system required for cells to receive RcGTA-donated DNA. Here, we report that dysregulation of the CckA-ChpT-CtrA phosphorelay either by the loss of the PAS domain protein DivL or by substitution of the autophosphorylation residue of the hybrid histidine kinase CckA decreased CtrA phosphorylation and greatly increased RcGTA protein production in We show that the loss of the ClpXP protease or the three C-terminal residues of CtrA results in increased CtrA levels in and identify ClpX(P) to be essential for the maturation of RcGTA particles. Furthermore, we show that CtrA phosphorylation is important for head spike production. Our results provide novel insight into the regulation of CtrA and GTAs in the Members of the are abundant in ocean and freshwater environments. The conserved GTA produced by many may have an important role in horizontal gene transfer (HGT) in aquatic environments and provide a significant contribution to their adaptation. GTA production is controlled by bacterial regulatory systems, including the conserved CckA-ChpT-CtrA phosphorelay; however, several questions about GTA regulation remain. Our identification that a short DivL homologue and ClpXP regulate CtrA in extends the model of CtrA regulation from to a member of the We found that the magnitude of RcGTA production greatly depends on DivL and CckA kinase activity, adding yet another layer of regulatory complexity to RcGTA. RcGTA is known to undergo CckA-dependent maturation, and we extend the understanding of this process by showing that the ClpX chaperone is required for formation of tailed, DNA-containing particles.

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“…ClpP substrate candidates were cloned with appropriate primers either into pET23SUMO plasmids for recombinant protein expression in E. coli (Wang et al ., ) or into pENTR plasmids for Gateway‐based cloning into expression plasmids for either E. coli or C. crescentus (Skerker et al ., ). ΔNClpX (removing residues 1–58) and full‐length ClpX were expressed in ClpX depletion strains (Jenal and Fuchs, ) using low‐copy plasmids downstream of the clpX promoter (Osteras et al ., ). Caulobacter strains harbouring alleles of TacA‐DD were generated by transforming wild type or Δ pdeA :tet (Skerker et al ., ) with pENTR TacA‐DD.…”

Section: Methodsmentioning

confidence: 97%

Identification of ClpP substrates in Caulobacter crescentus reveals a role for regulated proteolysis in bacterial development

Bhat

Vass

Stoddard

et al. 2013

Molecular Microbiology

107

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Energy dependent proteases ensure the timely removal of unwanted proteins in a highly selective fashion. In Caulobacter crescentus, protein degradation by the ClpXP protease is critical for cell cycle progression; however, only a handful of substrates are currently known. Here, we use a trapping approach to identify putative substrates of the ClpP associated proteases in C. crescentus. Biochemical validation of several of these targets reveals specific protease recognition motifs and suggests a need for ClpXP specific degradation beyond degradation of known cell cycle regulators. We focus on a particular instance of regulated proteolysis in Caulobacter by exploring the role of ClpXP in degrading the stalk synthesis transcription factor TacA. We show that TacA degradation is controlled during the cell cycle dependent on the ClpXP regulator CpdR and that stabilization of TacA increases degradation of another ClpXP substrate, CtrA, while restoring deficiencies associated with prolific CpdR activity. Together, our work reveals a number of new validated ClpXP substrates, clarifies rules of protease substrate selection, and demonstrates how regulated protein degradation is critical for Caulobacter development and cell cycle progression.

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Identification and Transcriptional Control of the Genes Encoding the Caulobacter crescentus ClpXP Protease

Cited by 34 publications

References 54 publications

The Global Regulatory Architecture of Transcription during the Caulobacter Cell Cycle

The Global Regulatory Architecture of Transcription during the Caulobacter Cell Cycle

The Protease ClpXP and the PAS Domain Protein DivL Regulate CtrA and Gene Transfer Agent Production in Rhodobacter capsulatus

Identification of ClpP substrates in Caulobacter crescentus reveals a role for regulated proteolysis in bacterial development

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