Non-templated oligo-adenylation of small RNAs in the parasite Entamoeba
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ABSTRACT:
ORGANISM(S): Entamoeba histolytica Entamoeba invadens
PROVIDER: GSE157756 | GEO | 2020/12/01
REPOSITORIES: GEO
Similar Datasets
Project description:Non-templated oligo-adenylation of small RNAs in the parasite Entamoeba
| PRJNA662625 | ENA
Project description:We provided a full spectrum analysis for E. histolytica AGO2-2 associated 27nt small RNAs. Additionally, comparative analysis of small RNA populations from virulent and non-virulent amebic strains indicates that small RNA populations may regulate virulence genes.
2013-01-24 | GSE43668 | GEO
Project description:We provided a full spectrum analysis for E. histolytica AGO2-2 associated 27nt small RNAs. Additionally, comparative analysis of small RNA populations from virulent and non-virulent amebic strains indicates that small RNA populations may regulate virulence genes. AGO2-2 bound small RNAs from E. histolytica strain HM-1:IMSS were immunoprecipitated and sequenced using 454 technology. Three independant sequencing runs were perfomed using the same RNA sample. In addition, size selected small RNAs from E. histolytica strain Rahman were sequenced with the same technology. One sequencing run was performed on this sample.
2013-01-24 | E-GEOD-43668 | biostudies-arrayexpress
Project description:Formation of templated insertions at DNA double-strand breaks (DSBs) is very common in cancer cells. The mechanisms and enzymes regulating these events are largely unknown. Here, we investigated templated insertions in yeast at DSBs using amplicon sequencing across a repaired locus. We document very short (most ~5-34 bp), templated inverted duplications at DSBs. They are generated through a foldback mechanism that utilizes microhomologies adjacent to the DSB. Enzymatic requirements suggest a hybrid mechanism wherein one end requires Polδ-mediated synthesis while the other end is captured by nonhomologous end joining (NHEJ). This process is exacerbated in mutants with low levels or mutated RPA (rtt105Δ; rfa1-t33) or extensive resection mutant (sgs1Δ exo1Δ). Templated insertions from various distant genomic locations also increase in these mutants as well as in rad27Δ and originate from fragile regions of the genome. Among complex events, common events are insertions of two sequences, originating from the same locus and with inverted orientation. Evidence suggests that inversions are also formed by microhomology-mediated template switching. Taken together, our results suggest that limited RPA, typical in many cancers, may contribute to the high level of microhomology-mediated templated insertions.
2024-03-07 | GSE260753 | GEO
Project description:BackgroundThe RNA interference (RNAi) pathway is a gene regulation mechanism that utilizes small RNA (sRNA) and Argonaute (Ago) proteins to silence target genes. Our previous work identified a functional RNAi pathway in the protozoan parasite Entamoeba histolytica, including abundant 27 nt antisense sRNA populations which associate with EhAgo2-2 protein. However, there is lack of understanding about the sRNAs that are bound to two other EhAgos (EhAgo2-1 and 2-3), and the mechanism of sRNA regulation itself is unclear in this parasite. Therefore, identification of the entire pool of sRNA species and their sub-populations that associate with each individual EhAgo protein would be a major step forward.ResultsIn the present study, we sequenced sRNA libraries from both total RNAs and EhAgo bound RNAs. We identified a new population of 31 nt sRNAs that results from the addition of a non-templated 3-4 adenosine nucleotides at the 3'-end of the 27 nt sRNAs, indicating a non-templated RNA-tailing event in the parasite. The relative abundance of these two sRNA populations is linked to the efficacy of gene silencing for the target gene when parasites are transfected with an RNAi-trigger construct, indicating that non-templated sRNA-tailing likely play a role in sRNA regulation in this parasite. We found that both sRNA populations (27 nt and 31 nt) are present in the related parasite Entamoeba invadens, and are unchanged during the development. In sequencing the sRNAs associating with the three EhAgo proteins, we observed that despite distinct cellular localization, all three EhAgo sRNA libraries contain 27 nt sRNAs with 5'-polyphosphate (5'-polyP) structure and share a largely overlapping sRNA repertoire. In addition, our data showed that a fraction of 31 nt sRNAs associate with EhAgo2-2 but not with its mutant protein (C-terminal deletion), nor other two EhAgos, indicating a specific EhAgo site may be required for sRNA modification process in the parasite.ConclusionWe identified a new population of sRNA with non-templated oligo-adenylation modification, which is the first such observation amongst single celled protozoan parasites. Our sRNA sequencing libraries provide the first comprehensive sRNA dataset for all three Entamoeba Ago proteins, which can serve as a useful database for the amoeba community.
| S-EPMC7724847 | biostudies-literature
Project description:Here we report that soon after mating of Oxytricha trifallax, abundant 27nt small RNAs are produced that are not present prior to mating. We performed next generation sequencing of these 27nt RNAs from various times after mating. Using sequence comparisons between macronuclear and micronuclear versions of genes, we found that this 27nt RNA class derives from the parental macronucleus, not the developing macronucleus. These small RNAs are produced equally from both strands of macronuclear nanochromosomes, but in a highly non-uniform distribution along the length of the nanochromosome, and with a particular depletion in the 30 nt telomere-proximal positions. Unlike the Tetrahymena scanRNAs, the Oxytricha macronuclear-derived 27mers are not modified by 2'O-methylation at their 3' ends.
2012-04-19 | GSE37390 | GEO
Project description:We analyzed ~27nt small RNAs from Entamoeba invadens trophozoites, 24h cysts, 72h cysts, and excysting cells (8h)
2015-07-22 | GSE67231 | GEO
Project description:We analyzed ~27nt small RNAs from Entamoeba histolytica trophozoites in basal conditions and after heat shock or oxidative stress
2015-07-22 | GSE67230 | GEO
Project description:Here we report that soon after mating of Oxytricha trifallax, abundant 27nt small RNAs are produced that are not present prior to mating. We performed next generation sequencing of these 27nt RNAs from various times after mating. Using sequence comparisons between macronuclear and micronuclear versions of genes, we found that this 27nt RNA class derives from the parental macronucleus, not the developing macronucleus. These small RNAs are produced equally from both strands of macronuclear nanochromosomes, but in a highly non-uniform distribution along the length of the nanochromosome, and with a particular depletion in the 30 nt telomere-proximal positions. Unlike the Tetrahymena scanRNAs, the Oxytricha macronuclear-derived 27mers are not modified by 2'O-methylation at their 3' ends. Examination of small RNAs produced in Oxytricha trifallax during vegetative growth and at various timepoints during the mating process
2012-04-19 | E-GEOD-37390 | biostudies-arrayexpress
Project description:Little is known about the extent of genetic variability among Entamoeba strains and potential genotypic associations with virulence. Variable phenotypes have been identified for Entamoeba strains. E. histolytica is invasive and causes colitis and liver abscesses, but only in 10% of infected individuals; 90% of subjects remain asymptomatically colonized. E. dispar, a closely related species, appears to be incapable of causing invasive disease. In order to determine the extent of genetic diversity among Entamoeba strains we have developed an E. histolytica genomic DNA microarray and used it to genotype strains of E. dispar and E. histolytica. Based on the identification of divergent genetic loci, all six strains (four EH and two ED) had unique genetic fingerprints. Genomic regions with unusually high levels of divergence were identified indicating that structural or evolutionary pressures are molding selective regions of the Entamoeba genome. Comparison of divergent genetic regions allowed us to readily distinguish between EH and ED, identify novel genetic regions that may be used for strain and species typing, and identity a number of novel potential virulence determinants. Among these are Androgen Inducible Gene1, a CXXC receptor kinase, a peroxiredoxin 1-related gene, a Ras family member gene, a Rab geranylgeranyltransferase, and a gene with a UPF0034 domain. Among the four EH strains, an avirulent strain EH (Rahman) was the most divergent and phylogenetically distinct raising the intriguing possibility that genetic subtypes of E. histolytica may be at least partially responsible for the observed variability in clinical outcomes. Our approach shows the utility of a microarray-based genotyping assay to identify genetic variability between Entamoeba isolates and can readily be applied to the study of clinical isolates. A genotyping experiment design type classifies an individual or group of individuals on the basis of alleles, haplotypes, SNP's. Keywords: genotyping_design
2005-08-26 | GSE3207 | GEO