Project description:Transactive response DNA-binding protein of 43 kDa (TDP-43), a heterogeneous nuclear ribonucleoprotein (hnRNP) with diverse activities, is a common denominator in several neurodegenerative disorders including amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD). Orthologs of TDP-43 exist from mammals to invertebrates, but their functions in lower organisms remain poorly understood. Here we systematically studied mutant Caenorhabditis elegans lacking the nematode TDP-43 ortholog, TDP-1. To understand the global gene expression regulation induced by the loss of tdp-1, the C. elegans transcriptomes were compared between the N2 WT animals and the tdp-1(ok803lf) mutant. Transcriptional profiling demonstrated that the loss of TDP-1 altered expression of genes functioning in RNA processing and protein folding. These results suggest that the C. elegans TDP-1 as an RNA-processing protein may have a role in the regulation of protein homeostasis and aging. Global gene expression profiling was performed to compare the transcriptome of wild-type (N2) Caenorabditis elegans and that of tdp-1(ok803) loss-of-function mutant. We analyzed mixed stages of Caenorabditis elegans, wild-type N2 versus tdp-1(ok803), using the Affymetrix C. elegans genome array. Three biological replicates were performed.
Project description:Transactive response DNA-binding protein of 43 kDa (TDP-43), a heterogeneous nuclear ribonucleoprotein (hnRNP) with diverse activities, is a common denominator in several neurodegenerative disorders including amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD). Orthologs of TDP-43 exist from mammals to invertebrates, but their functions in lower organisms remain poorly understood. Here we systematically studied mutant Caenorhabditis elegans lacking the nematode TDP-43 ortholog, TDP-1. To understand the global gene expression regulation induced by the loss of tdp-1, the C. elegans transcriptomes were compared between the N2 WT animals and the tdp-1(ok803lf) mutant. Transcriptional profiling demonstrated that the loss of TDP-1 altered expression of genes functioning in RNA processing and protein folding. These results suggest that the C. elegans TDP-1 as an RNA-processing protein may have a role in the regulation of protein homeostasis and aging. Global gene expression profiling was performed to compare the transcriptome of wild-type (N2) Caenorabditis elegans and that of tdp-1(ok803) loss-of-function mutant.
Project description:C. elegans mutants deleted for TDP-1, an ortholog of the neurodegeneration-associated RNA binding protein TDP-43, display only mild phenotypes. Nevertheless, transcriptome sequencing revealed that many RNAs were altered in accumulation and/or processing in the mutant. Analysis of these transcriptional abnormalities demonstrates that a primary function of TDP-1 is to limit formation or stability of double-stranded RNA. Specifically, we found that deletion of tdp-1: 1) preferentially alters the accumulation of RNAs with inherent double stranded structure (dsRNA); 2) increases the accumulation of nuclear dsRNA foci, 3) enhances the frequency of adenosine-to-inosine RNA editing, and 4) dramatically increases the amount of transcripts immunoprecipitable with a dsRNA-specific antibody, including intronic sequences, RNAs with antisense overlap to another transcript, and transposons. We also show that TDP-43 knockdown in human cells results in accumulation of dsRNA , indicating that suppression of dsRNA is a conserved function of TDP-43 in mammals. Altered accumulation of structured RNA may account for some of the previously described molecular phenotypes (e.g., altered splicing) resulting from reduction of TDP-43 function. 24 samples: 3 tdp-1 polyA samples with 3 N2 controls, 3 tdp1J2 immunoprecipitated samples and tdp1 total RNA input with 3 N2 J2 immunoprecipitated controls (with N2 input), 3 tdp1 total RNA samples for RNA editing analysis with 3 N2 total RNA controls and an adr-2 mutant control, 2 tdp1 CHIPseq samples with RNAsecontrol.