Metabolic rearrangements causing elevated proline and polyhydroxybutyrate accumulation during the osmotic adaptation response of Bacillus megaterium
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PROVIDER: PRJNA434394 | ENA |
REPOSITORIES: ENA
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Project description:First transcriptome analyses of Bacillus megaterium DSM319 grown under mild and severe salt stress (up to 1.8 M NaCl) to analyse the addaptation of the organism on transcriptome level
2020-01-13 | GSE110712 | GEO
Project description:For many years now, Bacillus megaterium has served as a microbial industrial strain for high-level production of recombinant proteins in the g/L-scale. Nevertheless, the impact of process-related stress has only been poorly characterized so far. Taking advantage of the recent technical developments for quantifying the cell at various molecular levels, we interrogated the osmotic stress response of B. megaterium using transcriptome, proteome, metabolome and fluxome analyses. Under osmotic upshift conditions, several stress response enzymes, iron scavenging, and reactive oxygen species (ROS) fighting proteins were upregulated. The downregulation of genes of the upper part of glycolysis resulted in the activation of the pentose phosphate pathway (PPP), generating an oversupply of NADPH. The (NADH/NAD+) ratio indicating the redox state of the cell was also altered, which was partially compensated by the higher production of lactate accompanied by the reduction of acetate secretion. NADH was produced mainly within the tricarboxylic acid cycle (TCA) cycle elucidated from the higher mRNA and protein levels of enzymes involved within this pathway. This adaptation mainly focused on the massive de novo synthesis of the compatible solute proline recruiting an osmo-dependent pathway to fulfil this requirement. 13C flux analyses confirmed these findings. Giving the high flux towards acetyl-CoA and large pool of NADPH, B. megaterium cells redirected the produced acetyl-CoA to the polyhydroxybutyrate (PHB) biosynthetic pathway under non-limiting nutrient condition, amassing around 30% of the CDW as PHB. This direct relation between osmotic stress and intracellular PHB content has been evidenced for the first time, thus opening new avenues for synthesizing this valuable biopolymer using varying salt concentrations under non-limiting nutrient conditions.
2020-05-26 | PXD015605 | Pride
Project description:For many years now, Bacillus megaterium serves as a microbial workhorse for the high-level production of recombinant proteins in the g/L-scale. However, efficient and stable production processes require the knowledge of the molecular adaptation strategies of the host organism to establish optimal environmental conditions. Here, we interrogated the osmotic stress response of B. megaterium using transcriptome, proteome, metabolome, and fluxome analyses. An initial transient adaptation consisted of potassium import and glutamate counterion synthesis. The massive synthesis of the compatible solute proline constituted the second longterm adaptation process. Several stress response enzymes involved in iron scavenging and reactive oxygen species (ROS) fighting proteins showed higher levels under prolonged osmotic stress induced by 1.8 M NaCl. At the same time, the downregulation of the expression of genes of the upper part of glycolysis resulted in the activation of the pentose phosphate pathway (PPP), generating an oversupply of NADPH. The increased production of lactate accompanied by the reduction of acetate secretion partially compensate for the unbalanced (NADH/NAD+) ratio. Besides, the tricarboxylic acid cycle (TCA) mainly supplies the produced NADH, as indicated by the higher mRNA and protein levels of involved enzymes, and further confirmed by 13C flux analyses. As a consequence of the metabolic flux toward acetyl-CoA and the generation of an excess of NADPH, B. megaterium redirected the produced acetyl-CoA toward the polyhydroxybutyrate (PHB) biosynthetic pathway accumulating around 30% of the cell dry weight (CDW) as PHB. This direct relation between osmotic stress and intracellular PHB content has been evidenced for the first time, thus opening new avenues for synthesizing this valuable biopolymer using varying salt concentrations under non-limiting nutrient conditions.
| S-EPMC7053513 | biostudies-literature
Project description:In Saccharomyces cerevisiae, Elevated Levels of Aneuploidy and Chromosome Rearrangements are Separable Genome Instability Events Controlled by the Tel1 and Mec1 Kinases Cancer cells often have elevated frequencies of chromosomal aberrations, and it is likely that loss of genome stability is one driving force behind tumorigenesis. Deficiencies in DNA replication, DNA repair, or cell cycle checkpoints can all contribute to increased rates of chromosomal duplications, deletions and translocations. The Saccharomyces cerevisiae proteins Tel1 and Mec1 (homologues of the human ATM and ATR proteins, respectively) are known to participate in the DNA damage response, replication checkpoint, and telomere maintenance pathways and are critical to maintain genome stability. In the absence of induced DNA damage, tel1 mec1 diploid yeast strains exhibit extremely high rates of chromosome aneuploidy. There is a significant bias towards trisomy of chromosomes II, VIII, X, and XII, whereas the smallest chromosomes I and VI are commonly monosomic. tel1 mec1 strains also demonstrate elevated levels of chromosome rearrangements, including translocations as well as interstitial duplications and deletions. Restoring wild-type telomere length with the Cdc13-Est2 fusion protein substantially reduces the amount of chromosome rearrangements in tel1 mec1 strains. This result suggests that most of the rearrangements are initiated by telomere-telomere fusions. However, the telomere defects associated with tel1 mec1 strains do not cause the high rate of aneuploidy, as restoring proper telomere function does not prevent cells from becoming aneuploid. Our data demonstrate that the same mutant genotype can produce both high levels of chromosome rearrangements and high levels of aneuploidy, and these two types of events occur through separate mechanisms.
2009-09-03 | GSE17903 | GEO
Project description:Here, we investigated for the first time the systems-wide response of B. subtilis to different simultaneous stresses, i.e. nutrient limitation and high osmolarity. To address the anticipated complexity of the cellular response networks, we combined chemostat experiments under conditions of carbon limitation, salt stress and osmoprotection with multi-omics analyses at the transcriptome, proteome, metabolome and fluxome levels. Our results indicate that the flux through central carbon and energy metabolism is very robust under all conditions studied. The key to achieve this robustness is the adjustment of the biocatalytic machinery to compensate for solvent-induced impairment of enzymatic activities during osmotic stress. The accumulation of the exogenously provided osmoprotectant glycine betaine helps the cell to rescue enzyme activities in the presence of high salt. A major effort of the cell during osmotic stress is the production of the compatible solute proline. This is achieved by the concerted adjustment of multiple reactions around the 2-oxoglutarate node, which drives metabolism towards the proline precursor glutamate. The fine-tuning of the transcriptional and metabolic networks involves functional modules that overarch the individual pathways.
2014-03-31 | GSE53333 | GEO
Project description:Here, we investigated for the first time the systems-wide response of B. subtilis to different simultaneous stresses, i.e. nutrient limitation and high osmolarity. To address the anticipated complexity of the cellular response networks, we combined chemostat experiments under conditions of carbon limitation, salt stress and osmoprotection with multi-omics analyses at the transcriptome, proteome, metabolome and fluxome levels. Our results indicate that the flux through central carbon and energy metabolism is very robust under all conditions studied. The key to achieve this robustness is the adjustment of the biocatalytic machinery to compensate for solvent-induced impairment of enzymatic activities during osmotic stress. The accumulation of the exogenously provided osmoprotectant glycine betaine helps the cell to rescue enzyme activities in the presence of high salt. A major effort of the cell during osmotic stress is the production of the compatible solute proline. This is achieved by the concerted adjustment of multiple reactions around the 2-oxoglutarate node, which drives metabolism towards the proline precursor glutamate. The fine-tuning of the transcriptional and metabolic networks involves functional modules that overarch the individual pathways. We applied transcriptomic, mass spectrometry-based protein, metabolite and 13C-metabolic flux analysis techniques to B. subtilis cells grown under well-controlled conditions in a glucose-limited chemostat at a growth rate of 0.1 h-1 under i) reference conditions, ii) in the presence of 1.2 M NaCl, and iii) in the presence of 1.2 M NaCl and 1 mM GB. Microarray hybridizations were performed with RNA from three biological replicates. The individual samples were labeled with Cy5; a reference pool containing equal amounts of RNA from all 9 samples was labeled with Cy3.
2014-03-31 | E-GEOD-53333 | biostudies-arrayexpress
Project description:We found that the non-essential amino acid L-Proline (L-Pro) acts as a signaling molecule that promotes the conversion of embryonic stem cells (ESCs) into mesenchymal-like, spindle-shaped, highly motile, invasive pluripotent stem cells. This embryonic stem cell-to-mesenchymal-like transition (esMT) is accompanied by a genome-wide remodeling of the transcriptome We used microarrays to elucidate whether a diverse transcriptional program is the basis of the morphological and motility differences between ESCs and L- Proline treated ESCs (PiCs) Total RNA was extracted from Control (ESCs) and L-Proline treated mouse embryonic stem cells (PiCs) and hybridized on Affimetrix microarrays.
2013-09-05 | E-GEOD-50603 | biostudies-arrayexpress
Project description:To identifiy osmotic stress responsive smRNAs, we used a deep-sequencing technique to profile small RNA populations in leaf and root tissues of plants under high osmotic stress and control conditions.
2012-09-19 | GSE36560 | GEO
Project description:Type 2 Diabetes (T2D) is a global health issue characterized by abnormal blood glucose levels and often associated with excessive hepatic gluconeogenesis. Increased circulating non-essential amino acids (NEAAs) are consistently observed in T2D individuals; however, the specific contribution of each amino acid to T2D pathogenesis remains less understood. Here, we reported an unexpected role of the NEAA proline in coordinating hepatic glucose metabolism by modulating paraspeckle, a nuclear structure scaffolded by the long noncoding RNA Neat1. Mechanistically, proline diminished paraspeckles in hepatocytes, liberating the retained mRNA species into cytoplasm for translation, including the mRNAs of Ppargc1a and Foxo1, contributing to enhanced gluconeogenesis and hyperglycemia. We further demonstrated that the proline-paraspeckle-mRNA retention axis existed in diabetic liver samples, and intervening this axis via paraspeckle restoration significantly alleviated hyperglycemia in both female and male diabetic mouse models. Collectively, our results not only delineated a previously unappreciated proline-instigated, paraspeckle-dependent mRNA retention mechanism regulating gluconeogenesis, but also spotlighted proline and paraspeckle as potential targets for managing hyperglycemia. This SuperSeries is composed of the SubSeries listed below.
2024-11-26 | GSE252452 | GEO
Project description:The goals of these studies are to explore the mechanisms that may account for evolutionary divergence of adaptive osmotic physiologies among taxa that occupy different osmotic niches. In a common-garden environment, we track genome expression responses to hyper-osmotic (brackish water) challenge during a time-course of acclimation, and contrast these responses between species. We seek to identify mechanisms that facilitate osmotic acclimation that are evolutionarily conserved between basal and derived physiologies, and also to identify mechanisms that are uniquely derived in alternate osmotic environments.
2013-09-06 | E-MTAB-1854 | biostudies-arrayexpress