Project description:The regulation of plant biomass degradation by fungi is critical to the carbon cycle, and applications in bioproducts and biocontrol. Trichoderma harzianum is an important plant biomass degrader, enzyme producer, and biocontrol agent, but few putative major transcriptional regulators have been deleted in this species. The T. harzianum ortholog of the transcriptional activator XYR1/XlnR/XLR-1 was deleted, and the mutant strains were analyzed by growth profiling, enzymatic activities, and transcriptomics on cellulose. From plate cultures, the Δxyr1 mutant had reduced growth on D-xylose, xylan, and cellulose, and from shake-flask cultures with cellulose, the Δxyr1 mutant had ~ 90% lower β-glucosidase activity, and no detectable β-xylosidase or cellulase activity. The comparison of the transcriptomes from 18 h shake-flask cultures on D-fructose, without a carbon source, and cellulose, showed major effects of XYR1 deletion whereby the Δxyr1 mutant on cellulose was transcriptionally most similar to the cultures without a carbon source. The cellulose induced 43 plant biomass-degrading CAZymes including xylanases as well as cellulases, and most of these had massively lower expression in the Δxyr1 mutant. Expression of a sub-set of carbon catabolic enzymes, other transcription factors, and sugar transporters was also lower in the Δxyr1 mutant on cellulose. In summary, T. harzianum XYR1 is the master regulator of cellulases and xylanases, as well as regulating carbon catabolic enzymes.
Project description:Cellulose is the most abundant component of plant litter, which is critical for terrestrial carbon cycling. Nonetheless, it remains unknown how climate changes affect cellulose-decomposing microorganisms. Here, we carried out a multi-year litterbag experiment to examine cellulose decomposition undergoing +3°C warming in an Oklahoma tallgrass prairie, USA. GeoChip 5.0M was employed to detect microbial functional genes.
Project description:Transposable elements (TE) have been shown to contrain functional transcription factor (TF) binding sites for long, but the extent to which TEs contribute TF binding sites is not well know. Here, we comprehensively mapped binding sites for 26 pairs of orthologous TFs, in two pairs of human and mouse cell lines (i.e., leukemia, and lymphoblast), along with epigenomic profiles representing DNA methylation and six histone modifications. We found that on average, 20% of TF binding sites were embedded in TEs. We further identified 710 TF-TE relationships in which certain TE subfamilies enriched for TF binidng sites. TE-derived TF binding peaks were also strongly associated with decreased DNA methylation and increased enhancer-associated histone marks. Most of the TE-derived TF binding sites were species-specific, but we also identified conserved binding sites. Additionally, 66% of TE-derived TF binding events were cell-type specific, associated with cell-type specific epigenetic landscape. For data usage terms and conditions, please refer to http://www.genome.gov/27528022 and http://www.genome.gov/Pages/Research/ENCODE/ENCODEDataReleasePolicyFinal2008.pdf To evaluate the contribution of transposable elements (TE) to transcription factor (TF) binding landscapes, we profiled ChIP-seq datasets for 26 TFs in two cell lines in human and mouse, generated by the ENCODE and MouseENCODE consortia. The epigenomic profiles were evaluated from six histone modification in each of the cell lines, also generated by the consortia. We added DNA methylation to the epigenomic profiles, using two complementary techniques, MeDIP-seq and MRE-seq. The mouse data related to this study are available through GSE57230: http://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE57230
Project description:Transposable elements (TE) have been shown to contrain functional transcription factor (TF) binding sites for long, but the extent to which TEs contribute TF binding sites is not well know. Here, we comprehensively mapped binding sites for 26 pairs of orthologous TFs, in two pairs of human and mouse cell lines (i.e., leukemia, and lymphoblast), along with epigenomic profiles representing DNA methylation and six histone modifications. We found that on average, 20% of TF binding sites were embedded in TEs. We further identified 710 TF-TE relationships in which certain TE subfamilies enriched for TF binidng sites. TE-derived TF binding peaks were also strongly associated with decreased DNA methylation and increased enhancer-associated histone marks. Most of the TE-derived TF binding sites were species-specific, but we also identified conserved binding sites. Additionally, 66% of TE-derived TF binding events were cell-type specific, associated with cell-type specific epigenetic landscape. For data usage terms and conditions, please refer to http://www.genome.gov/27528022 and http://www.genome.gov/Pages/Research/ENCODE/ENCODEDataReleasePolicyFinal2008.pdf To evaluate the contribution of transposable elements (TE) to transcription factor (TF) binding landscapes, we profiled ChIP-seq datasets for 26 TFs in two cell lines in human and mouse, generated by the ENCODE and MouseENCODE consortia. The epigenomic profiles were evaluated from six histone modification in each of the cell lines, also generated by the consortia. We added DNA methylation to the epigenomic profiles, using two complementary techniques, MeDIP-seq and MRE-seq. The human data related to this study are available through GSE56774: http://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE56774
Project description:Targeted protein degradation is a novel pharmacology established by drugs that recruit target proteins to E3 ubiquitin ligases. Based on the structure of the degrader and the target, different E3 interfaces are critically involved, thus forming defined "functional hotspots". Understanding disruptive mutations in functional hotspots informs on the architecture of the assembly, and highlights residues susceptible to acquire resistance phenotypes. Here, deep mutational scanning revealed hotspots that are conserved or specific for chemically distinct degraders and targets and validated hotspots mutated in patients that relapse from degrader treatment.
Project description:Targeted protein degradation is a novel pharmacology established by drugs that recruit target proteins to E3 ubiquitin ligases. Based on the structure of the degrader and the target, different E3 interfaces are critically involved, thus forming defined "functional hotspots". Understanding disruptive mutations in functional hotspots informs on the architecture of the assembly, and highlights residues susceptible to acquire resistance phenotypes. Here, we employ haploid genetics to show that hotspot mutations cluster in substrate receptors of hijacked ligases, where mutation type and frequency correlate with gene essentiality. A Hybrid capture assay reveals resistance-conferring mutations after degrader treatment. 29 putative target genes were selected to be sequenced. Target gene enrichment from gDNA of treated cells was performed, followed by amplification and sequencing to identify mutations.
Project description:Digital gene expression profiling (DGE) was used to compare the responses of Penicillium decumbens strains to different carbon sources including glucose, cellulose and cellulose-wheat bran. In both wild-type strain 114-2 and cellulase hyperproducing mutant JU-A10-T, transcription of lignocellulolytic enzymes were significantly up-regulated in the presense of cellulose. Relative to 114-2, coordinated up-regulation of lignocellulolytic enzymes and down-regulation of amylases and proteases were observed in JU-A10-T, especially in the cellulose-wheat bran medium. The expression of the principal β-glucosidase BGLI gene was not elevated in JU-A10-T, like the cellulases and hemicellulases, suggesting a different regulatory mechanism for this enzyme. Functional analysis of genes up-regulated in JU-A10-T relative to 114-2 also showed enrichment of proteins involved in amino acid synthesis, protein synthesis, and post-translational modification, compatible with the higher level of production of secreted proteins in JU-A10-T.