Project description:To establish the overall cell responses to peroxisomal proteotoxic stress, we analysed transcriptomes of NT- and LONP2-silenced cells using RNA sequencing in COS-7 and U2OS cells.
Project description:In order to elucidate on mRNA changes upon various proteotoxic stress conditions, synchronized WT (N2) worms were treated from L4 to day 1 of adulthood and collected for RNA extraction in the following
Project description:Study of the effect of cadmium on KO and overexpressor mutants of glycolate oxidase-GOX2, which is one of the main sources of H202 from peroxisomes. Reactive oxygen species (ROS) act as secondary messengers that can be sensed by specific redox sensitive proteins responsible for the activation of signal transduction culminating in altered gene expression. ROS, which are involved in different activities, elicit a wide range of protein modifications, which might elicit different gene expressions. The subcellular site, in which modifications in ROS/oxidation state occur, can also act as a specific cellular redox network signal. The chemical identity of ROS and their subcellular origin actually is a specific imprint on the transcriptome response. In recent years, a number of transcriptomic studies related to altered ROS metabolism in plant peroxisomes have been carried out. In this study, we made a meta-analysis of these transcriptomic findings to identify common transcriptional footprints for plant peroxisomal-dependent signaling at early and later time points. These footprints highlight the regulation of various metabolic pathways and gene families, which are also found in plant responses to several abiotic stresses. Major peroxisomal-dependent genes are associated with protein and endoplasmic reticulum (ER) protection at later stages of stress while, at earlier stages, these genes are related to hormone biosynthesis and signaling regulation. Further, in silico analyses allowed us to assign human orthologs to some of the peroxisomal-dependent genes, which are mainly associated with different cancer types pathologies. Peroxisomal footprints provide a valuable resource for assessing and supporting key peroxisomal functions in cellular metabolism under control and stress conditions across species.
Project description:Distinct retrograde signaling pathways have been identified for several cellular organelles. These pathways are important to maintain the function of these organelles in response to organelle-specific stress. Using Caenorhabditis elegans, we show for the first time that such a retrograde signaling also exists for peroxisomes. Analysis of the C. elegans transcriptome revealed that peroxisomal import stress caused by the knock-down of the peroxisomal matrix protein import receptor prx-5/PEX5 induces the compensatory up-regulation of genes involved in defense response and lipid metabolic processes, especially peroxisomal beta oxidation. We, therefore, propose that the peroxisomal retrograde signaling participates in the maintenance of peroxisomal function in response to peroxisomal import stress.
Project description:By performing ribosome profiling on squamous cell carcinoma stem cells (either control or S51A mutant) we found that the ISR translationally regulates a network of centrosomal proteins to help cellular recovery upon proteotoxic stress.
Project description:Leiomyosarcoma (LMS) is an aggressive cancer with few therapeutic options. LMS cells are more sensitive to proteotoxic stress compared to normal smooth muscle cells. We used small compound 2c to induce proteotoxic stress and compare the transcriptomic adaptations of immortalized human uterine smooth muscle cells (HUtSMC) and LMS cells SK-UT-1. We found that the expression of the heat shock proteins (HSP) gene family is upregulated with higher efficiency in normal cells. In contrast, upregulation of BH3-only proteins is higher in LMS cells. HSF1, the master regulator of HSP transcription, is sequestered into transcriptionally incompetent nuclear foci only in LMS cells, which explains the lower HSP upregulation. We also found that several compounds can enhance the cell death response to proteotoxic stress. Specifically, when low doses were used, an inhibitor of salt-inducible kinases (SIKs) and the inhibitor of IRE1, a key element of the unfolded protein response (UPR), support proteotoxic-induced cell death with strength in LMS cells and without effects on the survival of normal cells. Overall, our data provide an explanation for the higher susceptibility of LMS cells to proteotoxic stress and suggest a potential option for co-treatment strategies.
Project description:Purpose: Next-generation sequencing (NGS) has revolutionized systems-based analysis of cellular pathways. The goals of this study are to compare NGS-derived transcriptome profiling (RNA-seq) and transposon insertion mutagenesis (Tnseq) libraries of Lon deletions compared to wt Caulobacter crescentus. Methods: See Methods section of The Lon protease links nucleotide metabolism with proteotoxic stress for information regarding methods or contact lead correspondence. Briefly, Samples for RNAseq were extracted from wt and lon deletion strains grown to mid exponential phase. Methods: See Methods section of The Lon protease links nucleotide metabolism with proteotoxic stress for information regarding methods or contact lead correspondence. Briefly, Samples for Tnseq were generated by Eztn5 transposon mutagenesis. Conclusions: Our study represents the first detailed analysis of lon deletion comparison to wt caulobacter transcriptomes, with biologic replicates, generated by RNA-seq technology.