RAB protein controls Argonaute localization for proper miRNA function in C. elegans
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ABSTRACT:
PROVIDER: PRJNA594456 | ENA |
REPOSITORIES: ENA
Dataset's files
| Action | DRS | |||
|---|---|---|---|---|
| SRR10615269.fastq.gz | Fastqsanger.gz | |||
| SRR10615270.fastq.gz | Fastqsanger.gz | |||
| SRR10615271.fastq.gz | Fastqsanger.gz | |||
| SRR10615272.fastq.gz | Fastqsanger.gz | |||
| SRR10615273.fastq.gz | Fastqsanger.gz |
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Project description:MicroRNAs are critical regulators of gene expression in animals. To repress their target mRNAs, these small RNAs are first loaded onto Argonaute proteins to form the silencing complex called miRISC. The complex must then be transported to its target mRNA where it interacts mostly within the 3’UTR through base-pairing. After target repression, the constituents of the miRISC undergo degradation or recycling mediated through their accurate sorting and localization in the cell. While some reports have linked intracellular trafficking to miRNA activity, it is still unclear how these pathways coordinate to allow proper miRNA-mediated gene silencing and turnover. Through a forward genetic screen performed in the nematode Caenorhabditis elegans, we identified the RabGAP tbc-11 as an important factor for the miRNA pathway. We show that TBC-11 is likely a GAP for the small GTPase RAB-6 and that its regulation is required for miRNA function in animals. The absence of functional TBC-11 leads to the persistent activation of RAB-6, which increases the localization of miRNA-unloaded Argonaute ALG-1 on endomembranes. This inactive form of Argonaute accumulates on polysomes, leading to defective miRNA-mediated target mRNA repression. Together, our results establish the importance of intracellular trafficking for miRNA function and demonstrates the involvement of a small GTPase in proper Argonaute localization in vivo.
2021-03-16 | GSE141719 | GEO
Project description:Once loaded onto Argonaute proteins, microRNAs form a silencing complex called miRISC that targets mostly the 3'UTR of mRNAs to silence their translation. How microRNAs are transported to and from their target mRNA remains poorly characterized. While some reports linked intracellular trafficking to microRNA activity, it is still unclear how these pathways coordinate for proper microRNA-mediated gene silencing and turnover. Through a forward genetic screen using Caenorhabditis elegans, we identified the RabGAP tbc-11 as an important factor for the microRNA pathway. We show that TBC-11 acts mainly through the small GTPase RAB-6 and that its regulation is required for microRNA function. The absence of functional TBC-11 increases the pool of microRNA-unloaded Argonaute ALG-1 that is likely associated to endomembranes. Furthermore, in this condition, this pool of Argonaute accumulates in a perinuclear region and forms a high molecular weight complex. Altogether, our data suggest that the alteration of TBC-11 generates a fraction of ALG-1 that cannot bind to target mRNAs, leading to defective gene repression. Our results establish the importance of intracellular trafficking for microRNA function and demonstrate the involvement of a small GTPase and its GAP in proper Argonaute localization in vivo.
| S-EPMC8055011 | biostudies-literature
Project description:Comprehensive discovery of endogenous Argonaute binding sites in C. elegans
2009-11-24 | GSE19138 | GEO
Project description:Argonaute proteins associate with small non-coding RNAs such as microRNAs, piRNAs and siRNAs to regulate gene expression required for cell proliferation and differentiation. Thse Argonaute proteins are the major components of effector complexes of non-coding RNA pathways. In C. elegans, we identified PPM-2, a Mg2+/Mn2+-dependent serine/threonine phosphatase, as a new regulator of the small RNA pathways in C. elegans. We demonstrate that PPM-2 is involved in the regulation of the let-7 microRNA family but also in the regulation of nuclear RNAi as well as it contributes to the expression of piRNAs. The loss of ppm-2 affects the expression level of Type 1 piRNAs and the stability of ALG-1, PRG-1 and NRDE-3 Argonaute proteins by sending them to the proteasomal degradation pathway. Altogether, our findings suggest that PPM-2 is regulating the function of small non-coding RNA pathways by preventing Argonaute proteins to be degraded via the proteasomal pathway.
2021-08-01 | GSE136462 | GEO
Project description:Caenorhabditis elegans contains 25 Argonautes, of which, ALG-1 and ALG-2 are known to primarily interact with miRNAs. ALG-5 belongs to the AGO subfamily of Argonautes that includes ALG-1 and ALG-2, but its role in small RNA pathways is unknown. We analyzed by high-throughput sequencing the small RNAs associated with ALG-5, ALG-1 and ALG-2, as well as changes in mRNA expression in alg-5, alg-1 and alg-2 mutants. We show that ALG-5 defines a distinct branch of the miRNA pathway affecting the expression of genes involved in immunity, defense, and development. In contrast to ALG-1 and ALG-2, which associate with most miRNAs and have general roles throughout development, ALG-5 interacts with only a small subset of miRNAs and is specifically expressed in the germline where it localizes alongside the piRNA and siRNA machinery at P granules. alg-5 is required for optimal fertility and mutations in alg-5 lead to a precocious transition from spermatogenesis to oogenesis. Our results provide a near-comprehensive analysis of miRNA-Argonaute interactions in C. elegans and reveal a new role for miRNAs in the germline.
| S-EPMC5587817 | biostudies-literature
Project description:Argonaute proteins are at the core of the microRNA-mediated gene silencing pathway essential for animals. In C. elegans, the microRNA-specific Argonautes ALG-1 and ALG-2 regulate multiple processes required for proper animal developmental timing and viability. Here, we identified a new phosphorylation site, serine 642, on ALG-1 that modulates microRNA association. Mutating ALG-1 serine 642 into a phospho-mimicking residue impairs microRNA binding and causes embryonic lethality and post-embryonic phenotypes that are common with alteration of microRNA functions. Monitoring microRNA levels in alg-1 phosphorylation mutant animals reveal that miRNA passenger strands strongly increase but are not preferentially loaded into ALG-1, indicating that the miRNA binding defects could also lead to miRNA duplexes accumulation. Our genetic and biochemical experiments support the protein kinase A KIN-1 as the putative kinase that phosphorylates ALG-1 serine 642. Altogether, our data indicate that PKA triggers the ALG-1 phosphorylation to regulate its microRNAs association during C. elegans development.
2022-09-10 | GSE198352 | GEO
Project description:In animals Argonaute small-RNA pathways scan germline transcripts to silence self-replicating genetic elements. Little is known however about how endogenous gene expression is recognized and licensed. Here we show that the presence of introns and by inference the process of mRNA splicing prevents default Argonaute-mediated silencing in the C. elegans germline. Silencing of intronless genes is initiated independently of the piRNA pathway but nevertheless engages multiple components of the downstream amplification and maintenance mechanisms that mediate transgenerational silencing including both nuclear and cytoplasmic members of the worm-specific Argonaute gene family (WAGOs). Small RNAs amplified from intronless mRNAs can trans-silence cognate intron-containing genes. Interestingly, a second small RNA-independent cis-acting mode of silencing also acts on intronless mRNAs. Our findings suggest that cues put in place during mRNA splicing license germline gene expression and provide evidence for a splicing-dependent and dsRNA- and piRNA-independent mechanism that can program Argonaute silencing.
2021-06-28 | GSE178985 | GEO
Project description:Caenorhabditis elegans contains twenty-five Argonautes, of which, only ALG-1 and ALG-2 are known to interact with miRNAs. ALG-5 belongs to the AGO subfamily of Argonautes that includes ALG-1 and ALG-2, but its role in small RNA pathways is unknown. We analyzed by high-throughput sequencing the small RNAs associated with ALG-5, ALG-1, and ALG-2, as well as changes in mRNA expression in alg-5, alg-1, and alg-2 mutants.
2017-06-09 | GSE98935 | GEO
Project description:Comprehensive discovery of endogenous Argonaute binding sites in C. elegans Experiment Overall Design: Total RNA were extracted from whole alg-1(gk214) (alg-1(-)) and N2 (wildtype) worms and used to compare the expression profiles of genes that were targeted by ALG-1 protein.
2009-11-28 | E-GEOD-19138 | biostudies-arrayexpress
Project description:MicroRNAs (miRNA) associate with Argonaute proteins and negatively regulate gene expression by base pairing with complementary sequences in the 3’ UTRs of target genes. De novo coding variants in the human Argonaute gene AGO1 were reported to cause neurodevelopmental disorder (NDD) with intellectual disability (ID). Most of the altered amino acids are conserved between the miRNA associated Argonautes in H. sapiens and C. elegans, suggesting that the human AGO1 mutations could disrupt evolutionarily conserved functions in miRNA biogenesis or target repression. We genetically modeled four human AGO1 mutations in C. elegans by introducing identical mutations into the C. elegans AGO1 homolog, ALG-1. These alg-1 NDD mutations caused phenotypes in C. elegans indicative of disrupted miRNA processing, miRISC formation, and/or target repression. We show that the alg-1 NDD mutations are antimorphic as they cause developmental and molecular phenotypes stronger than those exhibited by the alg-1 null mutants, likely by sequestrating functional miRNA silencing complex (miRISC) components into non-functional complexes that fail to confer robust gene repression. The alg-1 NDD mutations cause allele-specific disruptions in mature miRNA profiles, both in overall abundances and ALG-1 NDD association, accompanied by perturbation of downstream gene expression, including altered translational efficiency and/or mRNA abundance. The perturbed genes include those with human orthologs whose dysfunction is associated with NDD. These cross-clade genetic studies illuminate fundamental Argonaute functions and provide insights into the conservation of miRNA-mediated post-transcriptional regulatory mechanisms.
2023-12-30 | GSE252063 | GEO