Project description:Investigation of whole genome gene expression level changes in a Caulobacter crescentus NA1000 dcdnL mutant, compared to the wild-type strain. In bacteria, transcription of housekeeping genes required for metabolic homeostasis and cell proliferation is guided by the sigma factor σ70. The conserved CarD-like transcriptional regulator, CdnL, associates with promoter regions where σ70 localizes and stabilizes the open promoter complex. Caulobacter crescentus cells lacking CdnL have severe morphological and growth defects. Our microarray experiment demonstrates how cdnL deletion affects the transcriptome of Caulobacter crescentus.
Project description:Investigation of whole genome gene expression level changes in a Caulobacter crescentus NA1000 delta-CCNA_00382 (ccrM) mutant, compared to the wild-type strain. The mutations engineered into this strain render it incapable of methylating its genome on the adenine at GANTC motifs. References for strains : WT: Marks, M.E., Castro-Rojas, C.M., Teiling, C., Du, L., Kapatral, V., Walunas, T.L. and Crosson, S. (2010) The genetic basis of laboratory adaptation in Caulobacter crescentus. J Bacteriol, 192, 3678-3688; Collier, J. and Shapiro, L. (2009) Feedback control of DnaA-mediated replication initiation by replisome-associated HdaA protein in Caulobacter. J Bacteriol, 191, 5706-5716. DccrM: Gonzalez, D. and Collier, J. (2013) DNA methylation by CcrM activates the transcription of two genes required for the division of Caulobacter crescentus. Mol Microbiol, 88, 203-218. A six chip study using total RNA recovered from three separate wild-type cultures of Caulobacter crescentus NA1000 and three separate cultures of a triple mutant strain, Caulobacter crescentus NA1000 delta-CCNA_00382 (ccrM), in which the ccrM gene coding for a DNA methyltransferase methylating the adenine in GANTC motifs is truncated and its product inactive. Each chip measures the expression level of 3933 genes from Caulobacter crescentus NA1000 with 3 probes per gene and with three-fold technical redundancy.
Project description:Although diminutive in size, bacteria possess highly diverse and spatially confined cellular structures. Two related alpha-proteobacteria, Sinorhizobium meliloti and Caulobacter crescentus, serve as models for investigating the genetic basis of morphologic variations. S. meliloti, a symbiont of leguminous plants, synthesizes multiple flagella and no prosthecae, whereas C. crescentus, a freshwater bacterium, has a single polar flagellum and stalk. The podJ gene, originally identified in C. crescentus for its role in polar organelle development, is split into two juxtaposed open reading frames, podJ1 and podJ2, in S. meliloti. Deletion of podJ1 interferes with flagellar motility, exopolysaccharide production, cell envelope integrity, cell division, and normal morphology, but not symbiosis. As in C. crescentus, the S. meliloti PodJ1 protein appears to act as a polarity beacon and localizes to the newer cell pole. Microarray analysis indicates that podJ1 affects the expression of at least 129 genes, the majority of which correspond to observed mutant phenotypes. The combination of phenotypic characterization, microarray analysis, and suppressor identification suggests that PodJ1 controls a core set of conserved elements, including flagellar and pili genes, the signaling proteins PleC and DivK, and the TacA transcriptional activator, while alternate downstream targets have evolved to suit the distinct lifestyles of individual species. Gene expression profiling of Sinorhizobium meliloti Rm1021 or its isogenic podJ1 deletion mutant, grown to mid exponential phase in rich medium, was performed using custom Affymetrix GeneChips.
Project description:The goal of this study was to measure the effects of nitric oxide exposure (using DETA NONOate as a nitric oxide donor) on transcription in Caulobacter. Untreated Caulobacter crescentus were grown to a density of 0.3 (at OD660) in PYE medium (pH 7) in rolled culture tubes. DETA-NONOate treated Caulobacter crescentus were grown to a density of 0.3 (at OD660), and then treated with 100 mM DETA NONOate for 30 minutes.
Project description:phyR encodes a general stress regulator protein that is conserved among several alpha-proteobacteria. This experiment is quantifying transcription in two Caulobacter strains: one strain is overexpressing phyR (gene CC3477); the other carries a phyR in-frame deletion. Both strains were cultured in M2 defined medium with xylose as the sole carbon source. The first strain (FC626) carries a plasmid integrated into the xylX locus; phyR is fused to the xylX promoter in this plasmid, generating a xylose-inducible phyR overexpression strain. The second strain (FC799) carries an in-frame deletion at the chromosomal phyR locus. Duplicate cultures of: 1) C. crescentus strain CB15 phyR in-frame deletion mutant , and 2) a xylose-inducible phyR overexpression strain, were cultured in M2 xylose defined medium and harvested at OD660=0.3
Project description:Investigation of whole genome gene expression level changes in a Caulonacter crescentus NA1000 Plac::CCNA_00382 (ccrM) mutant, compared to the wild-type strain. The mutations engineered into this strain cause the CcrM DNA methyltransferase to be overexpressed and the chromosome to be constitutively methylated at the adenine at GANTC motifs. References of strains: CcrMOE: Collier, J. and Shapiro, L. (2009) Feedback control of DnaA-mediated replication initiation by replisome-associated HdaA protein in Caulobacter. J Bacteriol, 191, 5706-5716. WT: Marks, M.E., Castro-Rojas, C.M., Teiling, C., Du, L., Kapatral, V., Walunas, T.L. and Crosson, S. (2010) The genetic basis of laboratory adaptation in Caulobacter crescentus. J Bacteriol, 192, 3678-3688; Collier, J. and Shapiro, L. (2009) Feedback control of DnaA-mediated replication initiation by replisome-associated HdaA protein in Caulobacter. J Bacteriol, 191, 5706-5716. A six chip study using total RNA recovered from three separate wild-type cultures of Caulonacter crescentus NA1000 and three separate cultures of a triple mutant strain, Caulonacter crescentus NA1000 Plac::CCNA_00382 (ccrM), in which the ccrM gene coding for a DNA methyltransferase methylating the adenine in GANTC motifs is truncated and its product inactive. Each chip measures the expression level of 3933 genes from Caulobacter crescentus NA1000 with 3 probes per gene and with three-fold technical redundancy.
Project description:This study is measuring the steady-state levels of mRNA in wild-type Caulobacter crescentus grown in M2 defined medium containing either ammonium or nitrate as the sole nitrogen source. Four independent cultures of Caulobacter crecentus were grown in each of two medium conditions: M2(nitrate)glucose and M2(ammonium)glucose. Cultures in each medium type were grown to OD660=0.3 and RNA was isolated from each.
Project description:This SuperSeries is composed of the following subset Series: GSE25996: Expression data from Caulobacter crescentus starved for carbon GSE25997: Expression data from Caulobacter crescentus (syn. C. vibrioides) swarmer and stalked cells starved for carbon GSE25998: Expression data from WT, DSigT and DSigU Caulobacter crescentus (syn. C. vibrioides) starved for carbon Refer to individual Series
Project description:An ability to sense and respond to changes in extracellular phosphate is critical to the survival of most bacteria. For Caulobacter crescentus, which typically lives in phosphate-limited environments, this process is especially crucial. Like many bacteria, Caulobacter responds to phosphate limitation through a conserved two-component signaling pathway called PhoR-PhoB, but the direct regulon of PhoB in this organism is unknown. Here, we use ChIP-Seq to map the global binding patterns of the phosphate-responsive transcriptional regulator PhoB in both phosphate-limited and -replete conditions. Combined with genome-wide expression profiling, our work demonstrates that PhoB is induced to regulate nearly 50 genes in phosphate-starved conditions. The PhoB regulon is comprised primarily of genes known or predicted to help Caulobacter scavenge for and import inorganic phosphate, including 15 different membrane transporters. We also investigated the regulatory role of PhoU, a widely conserved protein proposed to coordinate phosphate import with expression of the PhoB regulon by directly modulating the histidine kinase PhoR. However, our studies show that it likely does not play such a role in Caulobacter as depleting PhoU has no significant effect on PhoB-dependent gene expression. Instead, cells lacking PhoU exhibit a striking accumulation of large polyphosphate granules suggesting that PhoU participates in controlling intracellular phosphate metabolism. An allele of phoB bearing a C-terminal 3x-flag tag was integrated at its native locus, and ChIP followed by deep sequencing on Illumina MiSeq was performed on samples grown in rich medium, phosphate-limited medium, and in a pstS::Tn5 mutant background in rich medium.