SciP array data
Ontology highlight
ABSTRACT:
ORGANISM(S): Caulobacter vibrioides CB15
PROVIDER: GSE22062 | GEO | 2010/12/01
SECONDARY ACCESSION(S): PRJNA127479
REPOSITORIES: GEO
Similar Datasets
Project description:Progression through the Caulobacter cell cycle is driven by the master regulator CtrA, an essential two-component signaling protein that regulates the expression of nearly 100 genes. CtrA is abundant throughout the cell cycle except immediately prior to DNA replication. However, the expression of CtrA-activated genes is generally restricted to S-phase. We identify the conserved protein SciP (small CtrA inhibitory protein) and show that it accumulates during G1 where it inhibits CtrA from activating target genes. The depletion of SciP from G1 cells leads to the inappropriate induction of CtrA-activated genes and, consequently, a disruption of the cell cycle. Conversely, the ectopic synthesis of SciP is sufficient to inhibit CtrA-dependent transcription, also disrupting the cell cycle. SciP binds directly to CtrA without affecting stability or phosphorylation; instead SciP likely prevents CtrA from recruiting RNA polymerase. CtrA is thus tightly regulated by a protein-protein interaction which is critical to cell cycle progression. For the sciP depletion studies, the sciP depletion strain was grown to mid-exponential phase in rich media supplemented with xylose, synchronized, and swarmer cells released into either glucose or xylose. Following one cell cycle, swarmers were again isolated from the two conditions and compared directly on arrays. This was done in duplicate. For the sciP overexpression studies, a wild type strain harboring the plasmid pJS14-Pxyl-sciP was grown to mid-exponential phase and xylose added for 2 hours. A strain harboring an empty vector was treated identically. The two populations were compared directly on arrays. This was done in duplicate.
2010-12-01 | E-GEOD-22062 | biostudies-arrayexpress
Project description:The Caulobacter cell cycle includes in an asymmetric cell division that is driven by a core regulatory circuit comprised of 4 transcription factors (DnaA, GcrA, CtrA, and SciP) and a DNA methyltransferase (CcrM). Using a modified global 5M-bM-^@M-^Y RACE protocol we mapped 2,726 transcriptional start sites (TSS) in the 4mb Caulobacter genome and identified 586 cell cycle-regulated TSS. The core cell cycle circuit directly controls about 55% of cell cycle-regulated TSS by integrating multiple regulatory inputs within at least 322 promoters, providing a large number of transcription profiles from a small number of regulatory factors. Here, we identified previously unknown features of the core cell cycle circuit, including antisense TSS within dnaA and ctrA, plus newly identified TSS for ctrA and ccrM. Altogether, we identified 615 antisense TSS plus 241 genes that are transcribed from multiple TSS. The multiple TSS in the same promoter region often exhibit different cell cycle activation timing, These novel features of the global transcript profile add significant insight to the system architecture of the Caulobacter cell cycle regulatory circuit. Global 5' RACE was performed to measure Transcription Start Site activity at time points of the Caulobacter NA1000 cell cycle
2014-10-16 | E-GEOD-57364 | biostudies-arrayexpress
Project description:The Caulobacter cell cycle includes in an asymmetric cell division that is driven by a core regulatory circuit comprised of 4 transcription factors (DnaA, GcrA, CtrA, and SciP) and a DNA methyltransferase (CcrM). Using a modified global 5M-bM-^@M-^Y RACE protocol we mapped 2,726 transcriptional start sites (TSS) in the 4mb Caulobacter genome and identified 586 cell cycle-regulated TSS. The core cell cycle circuit directly controls about 55% of cell cycle-regulated TSS by integrating multiple regulatory inputs within at least 322 promoters, providing a large number of transcription profiles from a small number of regulatory factors. Here, we identified previously unknown features of the core cell cycle circuit, including antisense TSS within dnaA and ctrA, plus newly identified TSS for ctrA and ccrM. Altogether, we identified 615 antisense TSS plus 241 genes that are transcribed from multiple TSS. The multiple TSS in the same promoter region often exhibit different cell cycle activation timing, These novel features of the global transcript profile add significant insight to the system architecture of the Caulobacter cell cycle regulatory circuit. Global 5' RACE was performed to map Transcription Start Sites in the Caulobacter NA1000 genome
2014-10-16 | E-GEOD-57365 | biostudies-arrayexpress
Project description:The Caulobacter cell cycle includes in an asymmetric cell division that is driven by a core regulatory circuit comprised of 4 transcription factors (DnaA, GcrA, CtrA, and SciP) and a DNA methyltransferase (CcrM). Using a modified global 5’ RACE protocol we mapped 2,726 transcriptional start sites (TSS) in the 4mb Caulobacter genome and identified 586 cell cycle-regulated TSS. The core cell cycle circuit directly controls about 55% of cell cycle-regulated TSS by integrating multiple regulatory inputs within at least 322 promoters, providing a large number of transcription profiles from a small number of regulatory factors. Here, we identified previously unknown features of the core cell cycle circuit, including antisense TSS within dnaA and ctrA, plus newly identified TSS for ctrA and ccrM. Altogether, we identified 615 antisense TSS plus 241 genes that are transcribed from multiple TSS. The multiple TSS in the same promoter region often exhibit different cell cycle activation timing, These novel features of the global transcript profile add significant insight to the system architecture of the Caulobacter cell cycle regulatory circuit.
2014-10-16 | GSE57365 | GEO
Project description:The Caulobacter cell cycle includes in an asymmetric cell division that is driven by a core regulatory circuit comprised of 4 transcription factors (DnaA, GcrA, CtrA, and SciP) and a DNA methyltransferase (CcrM). Using a modified global 5’ RACE protocol we mapped 2,726 transcriptional start sites (TSS) in the 4mb Caulobacter genome and identified 586 cell cycle-regulated TSS. The core cell cycle circuit directly controls about 55% of cell cycle-regulated TSS by integrating multiple regulatory inputs within at least 322 promoters, providing a large number of transcription profiles from a small number of regulatory factors. Here, we identified previously unknown features of the core cell cycle circuit, including antisense TSS within dnaA and ctrA, plus newly identified TSS for ctrA and ccrM. Altogether, we identified 615 antisense TSS plus 241 genes that are transcribed from multiple TSS. The multiple TSS in the same promoter region often exhibit different cell cycle activation timing, These novel features of the global transcript profile add significant insight to the system architecture of the Caulobacter cell cycle regulatory circuit.
2014-10-16 | GSE57364 | GEO
Project description:The signals feeding into bacterial S-phase transcription are poorly understood. Cellular cycling in the alpha-proteobacterium Caulobacter crescentus is driven by a complex circuit of at least three transcriptional modules that direct sequential promoter firing during the G1, early and late S cell cycle phases. In alpha-proteobacteria, the transcriptional regulator GcrA and the CcrM methyltransferase epigenetically activate promoters of cell division and polarity genes that fire in S-phase. By evolving Caulobacter crescentus cells to cycle and differentiate in the absence of the GcrA/CcrM module, we discovered that phosphate deprivation and (p)ppGpp alarmone stress signals converge on S-phase transcriptional activation. The cell cycle oscillations of the CtrA protein, the transcriptional regulator CtrA that implements G1 and late S-phase transcription, are essential in our evolved mutants, but not in wild-type cells, showing that the periodicity in CtrA abundance alone can sustain cellular cycling without GcrA/CcrM. While similar nutritional sensing occurs in other alpha-proteobacteria, GcrA and CcrM are not encoded in the reduced genomes of obligate intracellular relatives. We thus propose that the nutritional stress response induced during intracellular growth obviated the need for an S-phase transcriptional regulator.
2023-11-09 | GSE135899 | GEO
Project description:Many bacteria acquire dissemination and virulence traits in G1-phase. CtrA, an essential and conserved cell cycle transcriptional regulator identified in the dimorphic alpha-proteobacterium Caulobacter crescentus, mysteriously switches from activating promoters in late S-phase to a different set in G1-phase. We found that a core and highly conserved determinant in the DNA-binding domain (DBD) of CtrA governs this promoter switch and that it is also required for promoter reprogramming in stationary phase in response to a (p)ppGpp alarmone signal perceived by the RNA polymerase beta subunit. A simple side chain modification in one critical residue of this DBD confers opposing developmental phenotypes and transcriptional activities. This region is also central to understanding the developmental reprogramming in the obligate intracellular Rickettsiae where replicative cells develop into dispersal cells and a naturally occurring polymorphism in the rickettsial DBD resembles a mutation that drives CtrA towards activation of the dispersal (G1-phase) program in Caulobacter.
2019-11-25 | GSE134017 | GEO
Project description:In the model organism Caulobacter crescentus, a network of two-component systems involving the response regulators CtrA, DivK and PleD coordinate cell cycle progression with differentiation. Active phosphorylated CtrA prevents chromosome replication in G1 cells while simultaneously regulating expression of genes required for morphogenesis and development. At the G1-S transition, phosphorylated DivK (DivK~P) and PleD (PleD~P) accumulate to indirectly inactivate CtrA, which triggers DNA replication initiation and concomitant cellular differentiation. The phosphatase PleC plays a pivotal role in this developmental program by keeping DivK and PleD phosphorylation levels low during G1, thereby preventing premature CtrA inactivation. Here, we describe CckN as a second phosphatase akin to PleC that dephosphorylates DivK~P and PleD~P in G1 cells. However, in contrast to PleC, we do not detect kinase activity with CckN. The effects of CckN inactivation are largely masked when PleC is present, but become evident when PleC and DivJ, the major kinase for DivK and PleD, are absent. Accordingly, mild overexpression of cckN restores most phenotypic defects of a pleC null mutant. We also show that CckN and PleC are proteolytically degraded in a ClpXP-dependent way well before the onset of the S phase. Surprisingly, known ClpX adaptors are dispensable for PleC and CckN proteolysis, suggesting the existence of adaptors specifically involved in proteolytic removal of cell cycle regulators. Since cckN expression is induced in stationary phase, depending on the stress alarmone (p)ppGpp, we propose that CckN acts as an auxiliary factor responding to environmental stimuli to modulate CtrA activity under suboptimal conditions.
2020-06-09 | GSE152025 | GEO
Project description:In α-proteobacteria, strict regulation of cell cycle progression is necessary for the specific cellular differentiation required for adaptation to diverse environmental niches. The symbiotic lifestyle of Sinorhizobium meliloti requires a drastic cellular differentiation that includes genome amplification. To achieve polyploidy, the S. meliloti cell cycle program must be altered to uncouple DNA replication from cell division. In the α-proteobacterium Caulobacter crescentus, cell cycle regulated transcription plays an important role in control of cell cycle progression but this has not been demonstrated in other α-proteobacteria. Here we describe a robust method for synchronizing cell growth that enabled the first global analysis of S. meliloti cell cycle regulated gene expression. The objective of the microarray-based cell cycle gene expression analysis was to determine which genes were transcriptionally regulated as a funciton of a cell cycle in order to understand the contribution of transcriptional regulation to the timing of cell cycle events. The microarray analysis identified 462 genes with cell cycle regulated transcripts, including several key cell cycle regulators, and genes involved in motility, attachment, and cell division. Only 28% of the 462 S. meliloti cell cycle regulated genes were also transcriptionally cell cycle regulated in C. crescentus. Furthermore, CtrA and DnaA binding motif analysis revealed little overlap between the cell cycle-dependent regulons of CtrA and DnaA in S. meliloti and C. crescentus. The predicted S. meliloti cell cycle regulon of CtrA, but not that of DnaA, was strongly conserved in more closely related α-proteobacteria with similar ecological niches as S. meliloti, suggesting that the CtrA cell cycle regulatory network may control functions of central importance to the specific lifestyles of α-proteobacteria. Gene expression levels were quantified in synchronously growing S. meliloti cultures across 8 time points and compared to gene expression levels in unsynchronized culture via a two-color custom agilent array A two-color array format was used with time point from synchronous culture being competed with a sample from unsynchronized culture (control same for all arrays) to determine the cell cycle-phase specific induction or repression of genes relative to batch culture which contains cells in all phases of the cell cycle. For each of the 8 cell cycle time points, four biological replicates were used resulting in 4 arrays per time point and a total of 32 arrays. The arrays also contained duplicates of each probe resulting in two technical replicates per biological replicate per time point.
2014-01-22 | E-GEOD-54208 | biostudies-arrayexpress
Project description:In α-proteobacteria, strict regulation of cell cycle progression is necessary for the specific cellular differentiation required for adaptation to diverse environmental niches. The symbiotic lifestyle of Sinorhizobium meliloti requires a drastic cellular differentiation that includes genome amplification. To achieve polyploidy, the S. meliloti cell cycle program must be altered to uncouple DNA replication from cell division. In the α-proteobacterium Caulobacter crescentus, cell cycle regulated transcription plays an important role in control of cell cycle progression but this has not been demonstrated in other α-proteobacteria. Here we describe a robust method for synchronizing cell growth that enabled the first global analysis of S. meliloti cell cycle regulated gene expression. The objective of the microarray-based cell cycle gene expression analysis was to determine which genes were transcriptionally regulated as a funciton of a cell cycle in order to understand the contribution of transcriptional regulation to the timing of cell cycle events. The microarray analysis identified 462 genes with cell cycle regulated transcripts, including several key cell cycle regulators, and genes involved in motility, attachment, and cell division. Only 28% of the 462 S. meliloti cell cycle regulated genes were also transcriptionally cell cycle regulated in C. crescentus. Furthermore, CtrA and DnaA binding motif analysis revealed little overlap between the cell cycle-dependent regulons of CtrA and DnaA in S. meliloti and C. crescentus. The predicted S. meliloti cell cycle regulon of CtrA, but not that of DnaA, was strongly conserved in more closely related α-proteobacteria with similar ecological niches as S. meliloti, suggesting that the CtrA cell cycle regulatory network may control functions of central importance to the specific lifestyles of α-proteobacteria. Gene expression levels were quantified in synchronously growing S. meliloti cultures across 8 time points and compared to gene expression levels in unsynchronized culture via a two-color custom agilent array
2014-01-22 | GSE54208 | GEO