Project description:This study was designed to measure the gene expression profile of human primary bronchial epithelial cells treated with Aspergillus protease.
Project description:Aspergillus fumigatus is the most common opportunistic mold pathogen of humans, causing invasive diseases in immunocompromised patients. In these patients, the fungus can invade the lungs and other organs, causing severe damage. Penetration of the pulmonary epithelium is a key step in the infectious process. A. fumigatus produces extracellular proteases to degrade the structural barriers of the host. The A. fumigatus transcription factor PrtT controls the expression of multiple secreted proteases. PrtT shows similarity to the fungal Gal4-type Zn(2)-Cys(6) DNA-binding domain of several transcription factors. In this work, we further investigate the function of this transcription factor by performing a transcriptional and a proteomic analysis of the ΔprtT mutant. The microarray analysis revealed several unexpected findings. In addition to a decrease in protease expression, expression of genes involved in iron uptake and ergosterol synthesis was dramatically decreased in the ΔprtT mutant. A second finding of interest is that deletion of PrtT resulted in the upregulation of four secondary metabolite clusters, including genes for the biosynthesis of pseurotin A. The proteomic analysis identified 15 proteins secreted by the A. fumigatus WT strain when grown on protein-rich skim-milk medium. Of these, the ΔprtT mutant expressed reduced levels of ALP1 protease, TppA tripeptidyl peptidase and a serine peptidase and increased levels of FAD-oxygenase, AspF chitosinase, EglC endoglucanase and Bgt1 glucanosyltransferase compared to the WT strain. This report highlights the complexity of gene regulation by PrtT.
Project description:To identify peanut Aspergillus-interactive and Aspergillus-resistance genes, we carried out a large scale peanut Expressed Sequence Tag (EST) project followed by a peanut microarray study. For expression profiling, resistant and susceptible peanut cultivars were infected with a mixture of Aspergillus flavus and parasiticus spores. Microarray analysis identified 65 and 1 genes in resistant (C20) and susceptible (TF) cultivars, respectively, that were up-regulated in response to Aspergillus infection. In addition we identified 40 putative Aspergillus-resistance genes that were constitutively up-expressed in the resistant cultivar in comparison to the susceptible cultivar. Some of these genes were homologous to peanut, corn, and soybean genes previously shown to confer resistance to fungal infection. These results provide a comprehensive genome-scale platform for future studies focused on developing Aspergillus-resistant peanut cultivars through conventional breeding, marker-assisted breeding, or biotechnological methods by gene manipulation.
Project description:Insects adapt to plant protease inhibitors (PIs) present in their diet by differentially regulating multiple digestive proteases. However, mechanisms regulating protease gene expression in insects are largely enigmatic. Ingestion of Capsicum annuum protease inhibitor-7 (CanPI-7) arrests growth and development of Helicoverpa armigera (Lepidoptera: noctuidae). Using de novo RNA sequencing and proteomic analysis, we examined the response of H. armigera larvae fed on recombinant C. annuum PI (CanPI) at different time intervals. Here, we present evidence supporting a dynamic transition in H. armigera protease expression upon CanPI feeding with general down-regulation of protease genes at early time points (0.5 to 6 h) and significant up-regulation of specific trypsin, chymotrypsin and aminopeptidase genes at later time points (12 to 48 h).
Project description:Investigation of whole genome gene expression level changes in Aspergillus nidulans AN1599 (PbcR) overexpression mutant, compared to the FGSC A4 wild-type strain. Overexpression of the Zn(II)2Cys6 –type transcription factor, AN1599.4 (PbcR, pimaradiene biosynthetic cluster regulator), activates a secondary metabolite gene cluster in Aspergillus nidulans. Activation of the pathway in Aspergillus nidulans lead to a production of ent-pimara-8(14),15-diene.
Project description:Degradation of plant biomass to fermentable sugars is of critical importance for the use of plant materials for biofuels. Filamentous fungi are ubiquitous organisms and major plant biomass degraders. Single colonies of some fungal species can colonize massive areas as large as five soccer stadia.During growth, the mycelium encounters heterogeneous carbon sources. Here we assessed whether substrate heterogeneity is a major determinant of spatial gene expression in colonies of Aspergillus niger. We analyzed whole-genome gene expression in five concentric zones of 5-day-old colonies utilizing sugar beet pulp as a complex carbon source. Growth, protein production and secretion occurred throughout the colony. Genes involved in carbon catabolism and nitrate utilization were expressed uniformly from the centre to the periphery whereas genes encoding plant biomass degrading enzymes were expressed differentially across the colony. A combined adaptive response of carbon-catabolism and enzyme production to locally available monosaccharides was observed. Finally, our results demonstrate a fine-tuning of the different enzymatic tools available in A. niger and reveal how this fungus adapts as it colonizes complex environments.
Project description:Constitutive MALT1 activity drives survival of malignant lymphomas addicted to chronic B-cell receptor (BCR) signaling, oncogenic CARD11, or the API2-MALT1 fusion oncoprotein. While MALT1 scaffolding induces NF-kB-dependent survival signaling, MALT1 protease function is thought to augment NF-kB activation by cleaving signaling mediators and transcriptional regulators in B-cell lymphomas. However, the pathological role of MALT1 protease function in lymphomagenesis is not well understood. Here, we show that TRAF6 controls MALT1-dependent activation of NF-kB transcriptional responses, but is dispensable for MALT1 protease activation driven by oncogenic CARD11. To uncouple enzymatic and non-enzymatic functions of MALT1, we analyzed TRAF6-dependent and -independent as well as MALT1 protease-dependent gene expression profiles downstream of oncogenic CARD11 and API2-MALT1. By cleaving and inactivating the RNA binding proteins Regnase-1 and Roquin-1/2, MALT1 protease induces post-transcriptional upregulation of genes like NFKBIZ/IkBz, NFKBID/IkBNS and ZC3H12A/Regnase-1 in activated B-cell-like diffuse large B-cell lymphoma (ABC DLBCL). We demonstrate that oncogene-driven MALT1 activity in ABC DLBCL cells regulates NFKBIZ and NFKBID induction on mRNA level via releasing a brake imposed by Regnase-1 and Roquin-1/2. Furthermore, MALT1 protease drives post-transcriptional gene induction in the context of the API2-MALT1 fusion created by the recurrent t(11;18)(q21;q21) translocation in mucosa-associated lymphoid tissue (MALT) lymphoma. Thus, MALT1 paracaspase acts as a bifurcation point for enhancing transcriptional and post-transcriptional gene expression in malignant lymphomas. Moreover, the identification of MALT1 protease selective target genes will provides specific biomarkers for the clinical evaluation of MALT1 inhibitors.