Project description:20(S)-Protopanaxadiol (PPD) and 20(S)-Protopanaxatriol (PPT) are major metabolites of ginseng in humans and are considered to have estrogenic activity in cellular bioassays. In this study, we conducted in silico analyses to determine whether PPD and PPT interact with estrogen receptor alpha (ERα) and compared them with ERα agonists, partial agonists, and antagonists to identify their ERα activity.
Project description:Cellular metabolism controls gene expression through allosteric interactions between metabolites and transcription factors. Methods to detect these regulatory interactions are mostly based on in vitro binding assays, but there are no methods to identify them at a genome-scale in vivo. Here we show that dynamic transcriptome and metabolome data identify metabolites that are potential effectors of transcription factors in E. coli. By switching the culture conditions between starvation and growth for 20 hours, we induced strong metabolite concentration changes and accompanying gene expression changes, which were measured by LC-MS/MS and RNA sequencing. From the transcriptome data we calculated the activity of 209 transcriptional regulators with Network Component Analysis, and then tested which metabolites correlated with these activities. This approach captured, for instance, the in vivo Hill-kinetics of CRP regulation by cyclic-AMP, a canonical example of allosteric transcription factor regulation in E. coli. By testing correlations between all pairs of transcription factors and metabolites, we predicted putative effectors of 65 transcription factors, and validated five of them in vitro. These results show that the combination of transcriptomics and metabolomics can generate hypotheses about metabolism-transcription interactions that are relevant in vivo and drive transitions between physiological states.
Project description:CoMet, a fully automated Computational Metabolomics method to predict changes in metabolite levels in cancer cells compared to normal references has been developed and applied to Jurkat T leukemia cells with the goal of testing the following hypothesis: up or down regulation in cancer cells of the expression of genes encoding for metabolic enzymes leads to changes in intracellular metabolite concentrations that contribute to disease progression. Nine metabolites predicted to be lowered in Jurkat cells with respect to normal lymphoblasts were examined: riboflavin, tryptamine, 3-sulfino-L-alanine, menaquinone, dehydroepiandrosterone, α-hydroxystearic acid, hydroxyacetone, seleno-L-methionine and 5,6-dimethylbenzimidazole. All, alone or in combination, exhibited antiproliferative activity. Of eleven metabolites predicted to be increased or unchanged in Jurkat cells, only two (bilirubin and androsterone) exhibited significant antiproliferative activity. These results suggest that cancer cell metabolism may be regulated to reduce the intracellular concentration of certain antiproliferative metabolites, resulting in uninhibited cellular growth and have the implication that many other endogenous metabolites with important roles in carcinogenesis are awaiting discovery. Keywords: cell type
Project description:Filamentous fungi are promising organisms for lignin degradation and mineralization. However, novel lignin-degrading fungal species are underexplored. Here, we isolated a fungal strain of Curvularia clavata that can utilize lignosulfonate as the carbon source and exhibited a relative high laccase activity during growth on lignosulfonate. Comparative transcriptomic analysis of the WT strain grown on glucose and lignosulfonate indicates that lignosulfonate and/or its metabolites have a significant effect on the gene expression profiles of C. clavata J1. Three regulators of laccase activity were identified, including a methyltransferase CcLaeA and two transcription factors, Rpn-4 and Tah-1. When grown on lignosulfonate, the laccase activity of the CclaeA and rpn-4 disrupted mutants (ΔCclaeA and Δrpn-4) increased by 49.2% and 43.5%, respectively, compared to the wild-type (WT) strain, whereas the tah-1 disrupted mutant (Δtah-1) decreased by 59.2%.
Project description:Staphylococcus aureus is a major human pathogen and resistant to numerous clinically used antibiotics. The first antibiotic developed for S. aureus infections was the nonribosomal petide secondary metabolite penicillin. We discovered cryptic nonribosomal peptide secondary metabolites, the aureusimines, made by S. aureus itself that are not antibiotics, but function as small molecule regulators of virulence factor expression. Using established rules and codes for nonribosomal peptide assembly we predicted these nonribosomal peptides, and used these predictions to identify them from S. aureus culture broths. Functional studies using global microarray and mouse bacteremia models established that the aureusimines control virulence factor expression and are necessary for productive infections. This is the first report of the aureusimines and has important implications for the treatment of drug resistant S. aureus. Targeting aureusimine synthesis may provide novel anti-infectives. Commerically available S. aureus GeneChips (Affymetrix) were used to compare biological replicates of early and late exponential phase wild type (Newman) and aureusimine defective (ausA) organisms.