Project description:Plants endo-beta-1,4-glucanases, belonging to Glycoside Hydrolase Family 9, have functional roles in cell wall biosynthesis and remodeling via endohydrolysis of (1-4)-beta-D-glucosidic linkages. Modification of cell wall chemistry via RNAi-mediated downregulation of PdKOR1, a endo-beta-1,4-glucanase gene, in Populus deltoides, has been shown to have functional consequences to the composition of secondary metabolome and ability of modified roots to interact with microbes. The molecular remodeling that underlies the observable differences at metabolic, physiological and morphological levels in roots is not well understood. Here we used a LC-MS/MS-based proteome profiling approach to survey the molecular remodeling in root tissues of PdKOR and control plants. A total of 14316 peptides were identified and these mapped to 7139 P. deltoides. Based on 90% sequence identity, the measured protein accessions represent 1187 functional protein groups. Analysis of GO categories and specific individual proteins shows differential expression of proteins relevant to plant-microbe interactions, cell wall chemistry and metabolism. This proteome dataset can serve as a useful resource for deriving new hypotheses and empirical testing pertaining to functional roles of proteins and pathways in differential priming of plant roots to interactions with microbes.
Project description:Cellulases and related β-1,4-glucanases are essential components of lignocellulose-degrading enzyme mixtures. The detection of β-1,4-glucanase activity typically relies on monitoring the breakdown of purified lignocellulose-derived substrates or synthetic chromogenic substrates, limiting the activities which can be detected and complicating the tracing of activity back to specific components within complex enzyme mixtures. As a tool for the rapid detection and identification of β-1,4-glucanases, a series of glycosylated cyclophellitol inhibitors mimicking β-1,4-glucan oligosaccharides have been synthesised. These compounds are highly efficient inhibitors of HiCel7B, a well-known GH7 endo-β-1,4-glucanase. An elaborated activity-based probe facilitated the direct detection of β-1,4-glucanases within a complex fungal secretome without any detectable cross-reactivity with β-D-glucosidases. These probes and inhibitors add valuable new capacity to the growing toolbox of cyclophellitol-derived probes for the activity-based profiling of biomass-degrading enzymes.
Project description:Characterization of a metagenomic regulatory sequence library derived from M. xanthus, E. coli, and O. urethralis genomes in strains expressing different RpoD ortholog variants. Targeted DNA and RNA seq used to profile relative DNA and RNA abundances, respectively of each regulatory sequence construct in the library.
Project description:We examined the effect of high-level expression of the commercially important endo-1,4-β-xylanase XynA on the B. subtilis transcriptome using RNA-seq. Rather unexpectedly, we found a reduced expression of several protein chaperones, including ClpC, ClpE and ClpX, was downregulated when XynA was overproduced. Expression of these proteins is controlled by the transcriptional repressor CtsR. CtsR levels are directly controlled by regulated proteolysis, involving ClpC and its cognate protease ClpP. Preventing this downregulation by knocking out the involved transcriptional repressor CtsR resulted in increased XynA production by more than 25 %.
Project description:Characterization of new bacterial catabolic genes and mobile genetic elements by high throughput genetic screening of a soil metagenomic library
Project description:E2 and GH are critical regulators of growth and intermediate metabolism in mammals. Hypothyroidism causes endocrine and metabolic disturbances in the liver with features that mimic deficiencies of E2 or GH signalling. In this work, we used the hypothyroid-orchiectomized (TXOX) adult rat model to evaluate the influence of E2 and GH on the liver in terms of global changes in gene expression. This study shows the changes in hepatic transcriptome that were provoked by E2 benzoate (50 ug/kg; sc; 5 days per week x 27 days), intermittent GH administration (0.3 mg/kg/day;sc injection divided into two daily injections x 7 days) or the combination of E2 plus GH in TXOX rats. E2 influenced the liver transcriptome, particularly genes involved in metabolism of lipids and endo-xenobiotics, and the GH-regulated endocrine, metabolic, gender, and immune responses. E2 did not prevent the inhibitory effects of GH on urea and amino acid metabolism-related genes. Notably, the combination of E2 and GH caused deleterious effects on transcriptional immune response. These results highlight the role of E2 as a critical regulator of liver metabolism in mammals and provide insights into the functional interplay between E2 and GH in the liver.