ABSTRACT: Microbial communities of polyhydroxyalkanoate (PHA)-based biodegradable composites plastisphere and of surrounding environmental matrix: a comparison between marine (seabed) and coastal sediments (dune sand) over a long-time scale
Project description:Pseudomonas putida KT2440 is an important bioplastic-producing industrial microorganism capable of synthesizing the polymeric carbon-rich storage material, polyhydroxyalkanoate (PHA). PHA is sequestered in discrete PHA granules, or carbonosomes, and accumulates under conditions of stress, for example low levels of available nitrogen. The pha locus responsible for PHA metabolism encodes both anabolic and catabolic enzymes, a transcription factor, and carbonosome-localized proteins termed phasins. The functions of phasins are incompletely understood but genetic disruption of their function causes PHA-related phenotypes. To improve our understanding of these proteins, we investigated the PHA pathways of P.putida KT2440 using three types of experiment. First, we profiled cells grown in nitrogen-limited and nitrogen-excess media using global expression proteomics, identifying sets of proteins found to co-ordinately increase or decrease within clustered pathway. Next, we analysed the protein composition of isolated carbonosomes, identifying two new putative components. We carried out physical interaction screens focused on PHA-related proteins, generating a protein-protein network comprising 434 connected proteins. Finally, we confirmed that the outer membrane protein OprL (the Pal component of the Pal-Tol system) localizes to the carbonosome and shows a PHA-related phenotype, and therefore is a novel phasin. The combined datasets represent a valuable overview of the protein components of the PHA system in P.putida highlighting the complex nature of regulatory interactions responsive to nutrient stress.
Project description:The pha-4 locus encodes a forkhead box A (FoxA/HNF3) transcription factor homolog that specifies organ identity for Caenorhabditis elegans pharyngeal cells. We used microarrays to identify pharyngeal genes and analyzed those genes to determine which were direct PHA-4 targets. Our data suggest that PHA-4 directly activates most or all pharyngeal genes. Furthermore, the relative affinity of PHA-4 for different TRTTKRY (R = A/G, K = T/G, Y = T/C) elements modulates the onset of gene expression, providing a mechanism to activate pharyngeal genes at different developmental stages. We suggest that direct transcriptional regulation of entire gene networks may be a common feature of organ identity genes. A genotyping experiment design type classifies an individual or group of individuals on the basis of alleles, haplotypes, SNP's. Keywords: genotyping_design
Project description:The effects of the CDK inhibitors PHA-848125 and PHA-690509 on the A2780 cell line were analysed by gene expression profiling. The A2780 cell line was treated with PHA-848125 (CDk-125) or PHA-690509 (CDk-509) for 6 hours at a dose equal to 5 times the IC50. Untreated A2780 cells were used as a control. Three replicates per treatment.
Project description:The direct photosynthetic production of polyhydroxyalkanoate in cyanobacteria was improved by increasing carbon flux to biosynthetic pathway and introducing enzyme with higher activity. To understand the global transcriptional changes under photoautotrophic PHA biosynthesis conditions, RNA-seq analysis was performed.
Project description:The direct photosynthetic production of polyhydroxyalkanoate in cyanobacteria was improved by increasing carbon flux to biosynthetic pathway and introducing enzyme with higher activity. To understand the global transcriptional changes under photoautotrophic PHA biosynthesis conditions, RNA-seq analysis was performed. Transcriptomes of recombinant Synechocystis sp. with different PHA-producing potential (three strains, two biological replicates for each strain) were analyzed.
Project description:The pha-4 locus encodes a forkhead box A (FoxA/HNF3) transcription factor homolog that specifies organ identity for Caenorhabditis elegans pharyngeal cells. We used microarrays to identify pharyngeal genes and analyzed those genes to determine which were direct PHA-4 targets. Our data suggest that PHA-4 directly activates most or all pharyngeal genes. Furthermore, the relative affinity of PHA-4 for different TRTTKRY (R = A/G, K = T/G, Y = T/C) elements modulates the onset of gene expression, providing a mechanism to activate pharyngeal genes at different developmental stages. We suggest that direct transcriptional regulation of entire gene networks may be a common feature of organ identity genes. A genotyping experiment design type classifies an individual or group of individuals on the basis of alleles, haplotypes, SNP's. Computed
Project description:The effects of the CDK inhibitor PHA-793887 on the A2780 human adenocarcinoma ovary cell line were analysed by gene expression profiling.
Project description:Phasin PhaF is a multifunctional protein associated with the surface of polyhydroxyalkanoate (PHA) granules (carbonosomes) that contributes significantly to PHA biogenesis in pseudomonads. PhaF participates in PHA granule stabilization and segregation and its deletion has a notable impact on overall transcriptome, PHA accumulation and cell physiology, suggesting a more extensive function than simply being a simply granule structural protein. We followed a systematic approach to detect potential interactions of PhaF with other components of the cell, which could pinpoint unexplored functions of PhaF in the regulation of PHA production. We determined the PhaF interactome in Pseudomonas putida KT2440 using pull-down-mass spectrometry (PD-MS), in which proteins interacting with PhaF were determined. We separately determined the PHA granule proteome (all proteins associated with PHA granules) in Pseudomonas putida KT2440 using two granule preparation methods.
