Project description:To understand the function and regulation of the C. elegans heat shock factor (HSF-1) in larval development, we have used ChIP-seq to analyze the occupancy of HSF1 and RNA Pol II in L2 larvae and young adult (YA) animals grown at 20°C or upon heat shock at 34°C for 30 min. In addition, we have used RNA-seq to analyze the transcriptomes of wild type (N2), hsf-1(ok600) mutants and hsf-1(ok600); rmSi1[hsf-1::gfp] L2 larvae grown at 20°C and characterized the gene expression change by heat shock in wild type (N2), hsf-1(sy441) and hsf-1(sy441);rmSi1[hsf-1::gfp] animals at L2 stage.
Project description:To understand the function and regulation of the C. elegans heat shock factor (HSF-1) in larval development, we have used ChIP-seq to analyze the occupancy of HSF1 and RNA Pol II in L2 larvae and young adult (YA) animals grown at 20°C or upon heat shock at 34°C for 30 min. In addition, we have used RNA-seq to analyze the transcriptomes of wild type (N2), hsf-1(ok600) mutants and hsf-1(ok600); rmSi1[hsf-1::gfp] L2 larvae grown at 20°C and characterized the gene expression change by heat shock in wild type (N2) animals at L2 stage.
Project description:To understand the function and regulation of the C. elegans heat shock factor (HSF-1) in larval development, we have used ChIP-seq to analyze the occupancy of HSF1 and RNA Pol II in L2 larvae and young adult (YA) animals grown at 20°C or upon heat shock at 34°C for 30 min. In addition, we have used RNA-seq to analyze the transcriptomes of wild type (N2), hsf-1(ok600) mutants and hsf-1(ok600); rmSi1[hsf-1::gfp] L2 larvae grown at 20°C and characterized the gene expression change by heat shock in wild type (N2) animals at L2 stage.
Project description:To mitigate the deleterious effects of temperature increases on cellular organization and proteotoxicity, organisms have developed mechanisms to respond to heat stress. In eukaryotes, HSF1 is the master regulator of the heat shock transcriptional response, but the heat shock response pathway is not yet fully understood. From a forward genetic screen for suppressors of heat shock induced gene expression in Caenorhabditis elegans, we found a new allele of hsf-1 that alters its DNA-binding domain, and we found three additional alleles of sup-45, a previously molecularly uncharacterized genetic locus. We identified sup-45 as one of the two hitherto unknown C. elegans orthologs of the human AF4/FMR2 family proteins, which are involved in regulation of transcriptional elongation rate. We thus renamed sup-45 as affl-2 (AF4/FMR2-Like). Through RNA-seq, we demonstrated that affl-2 mutants are deficient in heat shock induced transcription. Additionally, affl-2 mutants have herniated intestines, while worms lacking its sole paralog (affl-1) appear wild type. AFFL-2 is a broadly expressed nuclear protein, and nuclear localization of AFFL-2 is necessary for its role in heat shock response. affl-2 and its paralog are not essential for proper HSF-1 expression and localization after heat shock, which suggests that affl-2 may function downstream or parallel of hsf-1. Our characterization of affl-2 provides insights into the regulation of heat shock induced gene expression to protect against heat stress.
Project description:The goal of this RNA-Seq analysis was to identify genes differentially expressed in wild type (N2) and a hypomorphic mutant of the gene encoding heat shock factor 1 {hsf-1(sy441)} at normal conditions and upon heat shock. This study aimed to identify genes that are up- or downregulated when HSF-1 activity is impaired at 20 ºC. We also aimed to identify gene that are regulated by HSF-1 upon heat stress by comparing differentially expressed genes upon heat shock in wild type and in hsf-1(sy441) mutant background.
Project description:How lifespan and the rate of aging are set is a key problem in biology. Small RNAs are conserved molecules that impact diverse biological processes through the control of gene expression. However, in contrast to miRNAs, the role of endo-siRNAs in aging remains unexplored. Here, by combining deep sequencing and genomic and genetic approaches in C.CaenorhabditisC. elegans elegans, we reveal an unprecedented role for endo-siRNA molecules in the maintenance of proteostasis and lifespan extension in germline-less animals. Furthermore, we identify an endo-siRNA-regulated tyrosine phosphatase, which limits the longevity of germline-less animals by restricting the activity of the heat shock transcription factor HSF-1. Altogether, our findings point to endo-siRNAs as a link between germline removal and the HSF-1 proteostasis and longevity-promoting somatic pathway. This establishes a role for endo siRNAs in the aging process and identifies downstream genes and physiological processes that are regulated by the endo siRNAs to affect longevity.
Project description:Organisms' ability to respond to life-threatening environmental impacts is crucial for their survival. While acute stress responses to unfavorable factors are well known, the physiological consequences of transient stress experiences over time, as well as their underlying mechanisms, are not well understood. In this study, we investigated the long-term effects of a short heat shock (HS) exposure on the transcriptome of C. elegans. We found that the canonical HS response was followed by a profound transcriptional reprogramming affecting many genes involved in innate immunity response. This reprogramming relies on the endoribonuclease ENDU-2 but not the heat shock factor 1 (HSF-1). ENDU-2 in this context co-localizes with chromatin and interacts with RNA polymerase Pol II, enabling specific regulation of transcription in the post-HS period. Failure to activate this post-HS response does not impair animal survival under continuous HS insult but eliminates the beneficial effects of hormetic HS. In summary, our work discovers that the RNA-binding protein ENDU-2 mediates the hormetic long-term effects of transient HS to determine aging and longevity.