Project description:This SuperSeries is composed of the following subset Series: GSE4093: Resveratrol treatment of daf-16 mutant C. elegans GSE4094: N2 worms treated with Resveratrol GSE4095: Sir-2.1 low copy transgenic Abstract: C. elegans SIR-2.1, a member of the Sir-2 family of NAD(+)-dependent protein deacetylases, has been shown to regulate nematode aging via the insulin/IGF pathway transcription factor daf-16. Treatment of C. elegans with the small molecule resveratrol, however, extends life span in a manner fully dependent upon sir-2.1, but independent of daf-16. Microarray analysis of worms treated with resveratrol demonstrates the transcriptional induction of a family of genes encoding prion-like glutamine/asparagine-rich proteins involved in endoplasmic reticulum (ER) stress response to unfolded proteins. RNA interference of abu-11, a member of this ER stress gene family, abolishes resveratrol-mediated life span extension, and overexpression of abu-11 extends the life span of transgenic animals. Furthermore, SIR-2.1 normally represses transcription of abu-11 and other ER stress gene family members, indicating that resveratrol extends life span by inhibiting sir-2.1-mediated repression of ER stress genes. Our findings demonstrate that abu-11 and other members of its ER stress gene family are positive determinants of C. elegans life span. Refer to individual Series
Project description:Sirtuins, a family of histone deacetylases, have a fiercely debated role in regulating lifespan of different species. Contrasting recent observations, we here find that overexpression of sir-2.1, the orthologue of mammalian SirT1, does extend C. elegans lifespan. Sirtuins are known to convert NAD+ into nicotinamide (NAM). We here find that NAM and its metabolite, 1-methylnicotinamide (MNA), extend C. elegans lifespan, also in the absence of sir-2.1. Consistently, impairment of sir-2.1 prevents extension of lifespan by nicotinic acid (NA), a NAD+ precursor. Taken together, sirtuins extend lifespan by promoting formation of MNA to generate a phase I - mediated ROS signal, providing an unexpected mechanistic role for sirtuins beyond histone deacetylation.
Project description:Abstract: C. elegans SIR-2.1, a member of the Sir-2 family of NAD(+)-dependent protein deacetylases, has been shown to regulate nematode aging via the insulin/IGF pathway transcription factor daf-16. Treatment of C. elegans with the small molecule resveratrol, however, extends life span in a manner fully dependent upon sir-2.1, but independent of daf-16. Microarray analysis of worms treated with resveratrol demonstrates the transcriptional induction of a family of genes encoding prion-like glutamine/asparagine-rich proteins involved in endoplasmic reticulum (ER) stress response to unfolded proteins. RNA interference of abu-11, a member of this ER stress gene family, abolishes resveratrol-mediated life span extension, and overexpression of abu-11 extends the life span of transgenic animals. Furthermore, SIR-2.1 normally represses transcription of abu-11 and other ER stress gene family members, indicating that resveratrol extends life span by inhibiting sir-2.1-mediated repression of ER stress genes. Our findings demonstrate that abu-11 and other members of its ER stress gene family are positive determinants of C. elegans life span. This SuperSeries is composed of the SubSeries listed below.
Project description:Sirtuins, a family of histone deacetylases, have a fiercely debated role in regulating lifespan of different species. Contrasting recent observations, we here find that overexpression of sir-2.1, the orthologue of mammalian SirT1, does extend C. elegans lifespan. Sirtuins are known to convert NAD+ into nicotinamide (NAM). We here find that NAM and its metabolite, 1-methylnicotinamide (MNA), extend C. elegans lifespan, also in the absence of sir-2.1. Consistently, impairment of sir-2.1 prevents extension of lifespan by nicotinic acid (NA), a NAD+ precursor. Taken together, sirtuins extend lifespan by promoting formation of MNA to generate a phase I - mediated ROS signal, providing an unexpected mechanistic role for sirtuins beyond histone deacetylation. 9 samples: 3 mRNA profiles of C.elegans 48h after L4 exposed to nicotinic acid; 3 mRNA profiles of C.elegans 48h after L4 exposed to 1-MNA; 3 mRNA profiles of C.elegans 48h after L4 as controls (H20)
Project description:DNA microarray analyses were performed to determine the gene expression profiles of space-flown worms over four generations. N2 wild-type, RB756 hda-4 (ok518), and VC199 sir-2.1 (ok434) mutants were used to analyze epigenome alterations by histone deacetylase.
Project description:Small RNAs, including piRNAs, miRNAs and endogenous siRNAs, bind Argonaute proteins to form RNA-silencing complexes that target coding genes, transposons and aberrant RNAs. To assess the requirements for endogenous siRNA formation and activity in C. elegans, we developed a GFP-based sensor for the endogenous siRNA 22G siR-1, one of a set of abundant siRNAs processed from a precursor RNA mapping to the X chromosome, the X-cluster. Silencing of the sensor is also dependent on the partially complementary, unlinked 26G siR-O7 siRNA. We show that 26G siR-O7 acts in trans to initiate 22G siRNA formation from the X-cluster. The presence of several mispairs between 26G siR-O7 and the X-cluster mRNA, as well as mutagenesis of the siRNA sensor, indicates that siRNA target recognition is permissive to a degree of mispairing. From a candidate reverse genetic screen, we identified several factors required for 22G siR-1 activity, including the Argonaute ergo-1 and the 3' methyltransferase henn-1. Quantitative RT-PCR of small RNAs in a henn-1 mutant and deep sequencing of methylated small RNAs indicate that siRNAs and piRNAs that associate with PIWI clade Argonautes are methylated by HENN-1, while siRNAs and miRNAs that associate with non-PIWI clade Argonautes are not. Thus, PIWI-class Argonaute proteins are specifically adapted to associate with methylated small RNAs in C. elegans. This SuperSeries is composed of the SubSeries listed below.
Project description:Small RNAs, including piRNAs, miRNAs and endogenous siRNAs, bind Argonaute proteins to form RNA-silencing complexes that target coding genes, transposons and aberrant RNAs. To assess the requirements for endogenous siRNA formation and activity in C. elegans, we developed a GFP-based sensor for the endogenous siRNA 22G siR-1, one of a set of abundant siRNAs processed from a precursor RNA mapping to the X chromosome, the X-cluster. Silencing of the sensor is also dependent on the partially complementary, unlinked 26G siR-O7 siRNA. We show that 26G siR-O7 acts in trans to initiate 22G siRNA formation from the X-cluster. The presence of several mispairs between 26G siR-O7 and the X-cluster mRNA, as well as mutagenesis of the siRNA sensor, indicates that siRNA target recognition is permissive to a degree of mispairing. From a candidate reverse genetic screen, we identified several factors required for 22G siR-1 activity, including the Argonaute ergo-1 and the 3' methyltransferase henn-1. Quantitative RT-PCR of small RNAs in a henn-1 mutant and deep sequencing of methylated small RNAs indicate that siRNAs and piRNAs that associate with PIWI clade Argonautes are methylated by HENN-1, while siRNAs and miRNAs that associate with non-PIWI clade Argonautes are not. Thus, PIWI-class Argonaute proteins are specifically adapted to associate with methylated small RNAs in C. elegans. This SuperSeries is composed of the following subset Series: GSE34320: Analysis of 22G siRNA triggered siRNA amplification in Caenorhabditis elegans GSE34321: Analysis of 3' 2'-O-methylated small RNAs in Caenorhabditis elegans Refer to individual Series
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.