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:Comprehensive list of SUMO targets from the nematode Caenorhabditis elegans. SUMO conjugates isolated from transgenic worms carrying 8His and GFP tagged SUMO. The constructs rescues the lethal knock-out of a single SUMO gene, smo-1. SUMO conjugates where isolated from heat shock, arsenite exposure, and UV treated SUMO-GFP worms as well as from control non treated animals. In parallel identical purification procedure was performed with non-transgenic worms and proteins identified with this control where excluded.
Project description:Transcriptional profiling of heat-shocked worms was compared to non-heat-shocked worms to determine genes that are induced upon heat shock in each species; heat-shock-induced genes in each species were compared
Project description:After measuring the transcriptional response to increasing exposure of Caenorhabditis elegans N2 to 35 degrees Celsius, we wondered how recovery from heat-stress would progress. Hence, we exposed populations of the N2 strain to a 2 hour heat-shock of 35 degrees Celsius and took samples from 0 - 7 hours after termination of stress. This experiment was conduced in three biological replicates.
Project description:Increased exposure to heat-stress leads to an increasingly altered transcriptome in Caenorhabditis elegans. It is however unclear how the recovery from heat-stress progresses after increased heat-stress exposures. Hence, we exposed populations of the N2 strain to a 2, 3, 4, or 6 hour heat-shock of 35 degrees Celsius and took samples from 1 - 4 hours after termination of stress. This experiment was conduced in three biological replicates.
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:Young adult N2 Caenorhabditis elegans were infected with Enterococcus faecalis or Enterococcus faecium for 8 h to determine the transcriptional host response to each enterococcal species. Analysis of differential gene expression in C. elegans young adults exposed to four different bacteria: heat-killed Escherichia coli strain OP50 (control), wild-type E. faecalis MMH594, wild-type E. faecium E007, or Bacillus subtilis PY79 (sigF::kan). Samples were analyzed at 8 hours after exposure to the different bacteria. These studies identified C. elegans genes induced by pathogen infection. Brain-heart infusion agar plates (10 ug/ml kanamycin) were used.