WAGO-1 (Worm-specific Argonaute 1) is a member of the WAGO subfamily of Argonaute proteins that functions as a key effector in the endogenous small interfering RNA (endo-siRNA) pathway in the C. elegans germline. WAGO-1 binds 22G-RNAs, which are RNA-dependent RNA polymerase-derived secondary siRNAs characterized by their 22-nucleotide length and 5'-guanosine. Unlike canonical Argonaute proteins, WAGO subfamily members lack conserved metal-binding residues required for catalytic slicer activity and likely function through recruitment of other nucleases for target degradation. WAGO-1 localizes to P granules (germline nuage structures) where it functions in a genome surveillance system to silence transposons, pseudogenes, and cryptic loci. WAGO-1 acts downstream of the primary Argonaute PRG-1 in the piRNA pathway, where piRNA-triggered 22G-RNA production leads to loading of these secondary siRNAs into WAGO-1 and HRDE-1. WAGO-1 interacts with the Vasa homolog RDE-12 and the zinc-finger helicase ZNFX-1 as part of the RNA silencing machinery. The protein is enriched in sperm and oocytes and is essential for germline integrity and transposon control.
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0005634 nucleus | IBA GO_REF:0000033 | UNDECIDED | Summary: WAGO-1 is localized to cytoplasmic germ granules, with nuclear localization unresolved. Reason: Direct studies support P-granule localization and a cytoplasmic silencing role. Those positive results do not alone establish absence from every nuclear context. The nuclear IBA from PTN001875625 is left unresolved pending lineage-specific localization assessment; the separate WAGO catalytic-loss argument does not establish a localization loss. The existing OpenScientist report explicitly separates cytoplasmic WAGO-1/P-granule surveillance from nuclear HRDE-1/NRDE silencing. This supports the canonical compartment distinction but does not supply direct exclusion evidence for every possible nuclear WAGO-1 pool; no duplicate OpenScientist query was launched. Propagation Review Root cause: UNRESOLVED Sources checked: PANTHER:PTN001875625 · PTN001875625 UNRESOLVED The ancestral nuclear-localization assertion is traceable; target-specific evidence excluding a nuclear pool has not been established. Supporting Evidence: PMID:19800275 We show that, in the germline, one system is dependent on worm-specific AGOs, including WAGO-1, which localizes to germline nuage structures called P granules PMID:24684931 RDE-12 colocalizes with WAGO-1 in germline P granules and in cytoplasmic and perinuclear foci in somatic cells file:worm/wago-1/wago-1-deep-research-falcon.md the best-supported assignment is **WAGO-1 as primarily a cytoplasmic/perinuclear post-transcriptional effector** within the WAGO 22G-RNA surveillance pathway file:worm/wago-1/wago-1-deep-research-openscientist.md central cytoplasmic effector of the endogenous 22G-RNA silencing pathway in the germline |
| GO:0005737 cytoplasm | IBA GO_REF:0000033 | ACCEPT | Summary: IBA annotation for cytoplasmic localization is broadly consistent with experimental evidence showing WAGO-1 in cytoplasmic P granules. However, the more specific term GO:0043186 (P granule) is preferable as it captures the precise subcellular localization. Reason: Cytoplasmic localization is accurate - WAGO-1 localizes to cytoplasmic P granules (PMID:19800275, PMID:24684931). This is a valid parent term for the more specific P granule localization. Retaining as it provides broader context. Supporting Evidence: PMID:19800275 We show that, in the germline, one system is dependent on worm-specific AGOs, including WAGO-1, which localizes to germline nuage structures called P granules file:worm/wago-1/wago-1-deep-research-falcon.md WAGO-1 is consistently described as a **cytoplasmic/perinuclear germ-granule Argonaute** (P-granule localized) file:worm/wago-1/wago-1-deep-research-openscientist.md It localizes to perinuclear P granules (nuage) in germ cells |
| GO:0004521 RNA endonuclease activity | IBA GO_REF:0000033 | REMOVE | Summary: This annotation is phylogenetically inferred from slicer-competent Argonaute proteins. However, WAGO subfamily Argonautes specifically lack the conserved metal-binding residues (DDH/DDX catalytic tetrad) required for endonuclease activity. UniProt explicitly notes that WAGO subfamily members lack conserved metal-binding residues and probably do not cleave target mRNAs directly (PMID:17110334). Reason: WAGO-1 lacks the catalytic tetrad required for RNA endonuclease (slicer) activity. This is a known distinguishing feature of the WAGO subfamily. The protein likely recruits other endonucleases for target degradation rather than performing cleavage itself. This annotation is an over-annotation based on ancestral function that has been lost in this subfamily. Propagation Review Root cause: PROPAGATION BAD Failure modes: PSEUDO OR SUBACTIVITY LOSS Sources checked: PANTHER:PTN008584027 · PTN008584027 SUPPORTS SOURCE BUT NOT TARGET The ancestral Argonaute assertion is genuine, but WAGO-1 belongs to the specialized secondary-siRNA effector branch. Its established 22G-RNA specificity and non-slicer mechanism do not support transfer of this particular activity. Supporting Evidence: PMID:17110334 these AGO proteins lack key residues required for mRNA cleavage file:worm/wago-1/wago-1-deep-research-falcon.md WAGO-family Argonautes were reported to **lack the catalytic residues required for Slicer activity**, implying WAGO-mediated silencing often occurs via **cleavage-independent mechanisms** file:worm/wago-1/wago-1-deep-research-openscientist.md WAGO-1 binds secondary small interfering RNAs (22G-RNAs) |
| GO:0035194 regulatory ncRNA-mediated post-transcriptional gene silencing | IBA GO_REF:0000033 | ACCEPT | Summary: WAGO-1 is a central effector in the 22G-RNA pathway, which is a form of endo-siRNA-mediated gene silencing. The protein binds 22G-RNAs and mediates silencing of transposons, pseudogenes, and aberrant transcripts in the germline (PMID:19800275). This is a core function of WAGO-1. Reason: This annotation accurately captures WAGO-1's primary biological function. WAGO-1 participates in a regulatory ncRNA-mediated silencing pathway using endogenous 22G-RNAs. Experimental evidence from PMID:19800275 demonstrates this function directly. Supporting Evidence: PMID:19800275 WAGO-1 silences certain genes, transposons, pseudogenes, and cryptic loci file:worm/wago-1/wago-1-deep-research-falcon.md WAGO-1 is an Argonaute effector** that binds **secondary 22G-RNAs** and mediates **germline silencing / genome surveillance** of targets including **transposons, pseudogenes, and cryptic loci** |
| GO:0016442 RISC complex | IBA GO_REF:0000033 | ACCEPT | Summary: As an Argonaute protein that binds small RNAs and mediates gene silencing, WAGO-1 functions as part of an RNA-induced silencing complex. While the worm-specific WAGO-1-containing complex may have distinct features, RISC complex is an appropriate general term for Argonaute-containing silencing effector complexes. Reason: WAGO-1 is the core Argonaute component of a small RNA-mediated silencing complex. It associates with 22G-RNAs and interacts with RDE-12 (PMID:24684931) and ZNFX-1 (PMID:29775580) as part of the silencing machinery. RISC complex appropriately describes this functional complex. Supporting Evidence: PMID:24684931 RDE-12 forms an RNase-resistant (target mRNA-independent) complex with WAGO-1 PMID:17110334 several other AGO proteins interact with amplified siRNAs to mediate downstream silencing file:worm/wago-1/wago-1-deep-research-falcon.md RdRP-produced 22G-RNAs can be loaded onto WAGOs “**without Dicer**” processing |
| GO:0036464 cytoplasmic ribonucleoprotein granule | IBA GO_REF:0000033 | ACCEPT | Summary: P granules are a type of cytoplasmic ribonucleoprotein granule. WAGO-1 has been directly demonstrated to localize to P granules (PMID:19800275). This term is appropriate as a parent term, though the more specific GO:0043186 (P granule) is also annotated with experimental evidence. Reason: This is a valid broader annotation. P granules are cytoplasmic ribonucleoprotein granules, and WAGO-1 localizes to P granules (PMID:19800275, PMID:24684931). The IBA annotation is consistent with experimental data. Supporting Evidence: PMID:19800275 We show that, in the germline, one system is dependent on worm-specific AGOs, including WAGO-1, which localizes to germline nuage structures called P granules file:worm/wago-1/wago-1-deep-research-falcon.md Germ granules are **perinuclear, RNA-rich, membrane-less condensates** at the cytoplasmic face of germline nuclei file:worm/wago-1/wago-1-deep-research-openscientist.md It localizes to perinuclear P granules (nuage) in germ cells |
| GO:0035198 miRNA binding | IBA GO_REF:0000033 | MODIFY | Summary: This annotation is phylogenetically inferred from miRNA-binding Argonautes. However, WAGO-1 specifically binds 22G-RNAs (endogenous siRNAs), not miRNAs. The 22G-RNA pathway is distinct from the miRNA pathway in C. elegans. WAGO-1 binds secondary siRNAs produced by RNA-dependent RNA polymerases, which are structurally and functionally distinct from miRNAs. Reason: WAGO-1 binds 22G-RNAs (endogenous siRNAs), not miRNAs. The miRNA binding annotation is an over-generalization from other Argonaute family members. The appropriate term is siRNA binding (GO:0035197), which accurately describes binding to the 21-23 nt small interfering RNAs that WAGO-1 associates with. Propagation Review Root cause: PROPAGATION BAD Failure modes: FUNCTIONAL DIVERGENCE Sources checked: PANTHER:PTN001113179 · PTN001113179 SUPPORTS SOURCE BUT NOT TARGET The ancestral Argonaute assertion is genuine, but WAGO-1 belongs to the specialized secondary-siRNA effector branch. Its established 22G-RNA specificity and non-slicer mechanism do not support transfer of this particular activity. Proposed replacements: siRNA binding Supporting Evidence: PMID:17110334 several other AGO proteins interact with amplified siRNAs to mediate downstream silencing file:worm/wago-1/wago-1-deep-research-falcon.md WAGO-1 associates with **22G-RNAs**: Gu et al. show **transposon 22G-RNAs** are enriched in **WAGO-1 immunoprecipitation** samples file:worm/wago-1/wago-1-deep-research-openscientist.md WAGO-1 binds secondary small interfering RNAs (22G-RNAs) |
| GO:0003727 single-stranded RNA binding | IBA GO_REF:0000033 | ACCEPT | Summary: Argonaute proteins bind single-stranded guide RNAs. WAGO-1 binds 22G-RNAs in their single-stranded form after processing. This is a valid general molecular function annotation for an Argonaute protein. Reason: WAGO-1 binds single-stranded 22G-RNAs as guide RNAs for target recognition. This is a core molecular function of Argonaute proteins. The annotation is appropriate though more specific terms like siRNA binding would also be accurate. Supporting Evidence: PMID:17110334 Argonaute (AGO) proteins interact with small RNAs to mediate gene silencing file:worm/wago-1/wago-1-deep-research-falcon.md **22G-RNAs** are ~22-nt small RNAs with a strong **5′ guanosine (5′G) bias** |
| GO:0003676 nucleic acid binding | IEA GO_REF:0000002 | ACCEPT | Summary: IEA annotation based on InterPro domains (PAZ and Piwi domains). This is a very broad term that is subsumed by more specific RNA binding annotations. While technically correct, it provides little informative value given the more specific annotations. Reason: This is a valid but very general annotation based on domain composition. The PAZ and Piwi domains are nucleic acid binding domains. More specific annotations (RNA binding, siRNA binding) are also present and more informative. |
| GO:0003723 RNA binding | IEA GO_REF:0000002 | ACCEPT | Summary: IEA annotation based on InterPro PAZ domain (IPR003100). WAGO-1 contains PAZ and Piwi domains characteristic of Argonaute proteins that bind small RNAs. This is a valid general annotation. Reason: WAGO-1 binds 22G-RNAs through its PAZ and Piwi domains. RNA binding is a core molecular function. This annotation is appropriate as a broader classification of the siRNA binding activity. |
| GO:0031047 regulatory ncRNA-mediated gene silencing | IEA GO_REF:0000043 | ACCEPT | Summary: IEA annotation based on UniProtKB keyword mapping (RNA-mediated gene silencing). This term encompasses both transcriptional and post-transcriptional silencing. WAGO-1 primarily functions in post-transcriptional silencing (GO:0035194), which is a child term already annotated. Reason: This is a valid parent term for the more specific post-transcriptional silencing annotation. WAGO-1 is involved in regulatory ncRNA-mediated gene silencing using 22G-RNAs. Both this term and the more specific GO:0035194 are appropriate. Supporting Evidence: file:worm/wago-1/wago-1-deep-research-falcon.md Gu et al. describe WAGO-1 as part of a **germline 22G-RNA genome surveillance pathway**, mediating silencing of **transposons and other aberrant/cryptic loci** |
| GO:0017151 DEAD/H-box RNA helicase binding | IPI PMID:24684931 The Vasa Homolog RDE-12 engages target mRNA and multiple arg... | ACCEPT | Summary: This annotation is based on the physical interaction between WAGO-1 and RDE-12, a Vasa homolog DEAD-box RNA helicase. PMID:24684931 identified RDE-12 as a robust interaction partner of WAGO-1 through immunoprecipitation studies. RDE-12 is required for secondary siRNA production and colocalizes with WAGO-1 in P granules. Reason: This is a well-supported experimental annotation. PMID:24684931 directly demonstrated physical interaction between WAGO-1 and RDE-12 (P90897), a DEAD-box RNA helicase. This interaction is functionally important for RNAi and endo-siRNA pathways. Supporting Evidence: PMID:24684931 These studies identified a robust association between WAGO-1 and a conserved Vasa ATPase-related protein RDE-12 PMID:24684931 RDE-12 colocalizes with WAGO-1 in germline P granules and in cytoplasmic and perinuclear foci in somatic cells |
| GO:0043186 P granule | IDA PMID:19800275 Distinct argonaute-mediated 22G-RNA pathways direct genome s... | ACCEPT | Summary: This is a direct experimental annotation showing WAGO-1 localization to P granules. PMID:19800275 demonstrated that WAGO-1 localizes to germline nuage structures called P granules. This is a key finding that establishes the subcellular context for WAGO-1 function in germline gene silencing. Reason: Direct experimental evidence (IDA) demonstrating P granule localization. This is a core cellular component annotation supported by primary literature. P granule localization is essential for WAGO-1's function in germline surveillance. Supporting Evidence: PMID:19800275 We show that, in the germline, one system is dependent on worm-specific AGOs, including WAGO-1, which localizes to germline nuage structures called P granules PMID:24684931 RDE-12 colocalizes with WAGO-1 in germline P granules and in cytoplasmic and perinuclear foci in somatic cells file:worm/wago-1/wago-1-deep-research-falcon.md Chen et al. (2024) explicitly list **“P granule localized CSR-1 and WAGO-1”** in the context of germ granule subcompartment architecture file:worm/wago-1/wago-1-deep-research-openscientist.md It localizes to perinuclear P granules (nuage) in germ cells |
| GO:0010526 transposable element silencing | IMP PMID:19800275 Distinct argonaute-mediated 22G-RNA pathways direct genome s... | NEW | Summary: WAGO-1 functions in silencing transposons as part of the germline genome surveillance system. This is a key biological process function demonstrated in PMID:19800275. Reason: Transposon silencing is a primary function of the WAGO-1 22G-RNA pathway in the germline. This should be annotated as a core biological process function. Supporting Evidence: PMID:19800275 WAGO-1 silences certain genes, transposons, pseudogenes, and cryptic loci file:worm/wago-1/wago-1-deep-research-falcon.md together with related silencing WAGOs (including PPW-2/WAGO-3 and HRDE-1/WAGO-9) that preferentially target **silenced germline genes, pseudogenes, and repetitive/transposable elements** |
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Download this section (compressed HTML)Q: What is the mechanism by which WAGO-1, lacking endonuclease activity, achieves target mRNA degradation? Does it recruit specific nucleases?
Q: How is the balance between WAGO-1 (silencing) and CSR-1 (protecting) pathways maintained for genome surveillance in the germline?
Q: Does WAGO-1 have any transcriptional silencing functions in addition to post-transcriptional silencing?
Experiment: Identify nucleases recruited by WAGO-1 for target degradation using proximity labeling or co-IP followed by mass spectrometry
Hypothesis: WAGO-1 recruits specific endonucleases to P granules for target mRNA cleavage since it lacks intrinsic slicer activity
Experiment: Determine the complete catalog of WAGO-1 22G-RNA targets using CLIP-seq or similar approaches
Hypothesis: WAGO-1 targets a defined set of transposons, pseudogenes, and cryptic loci distinct from CSR-1 targets
Experiment: Test whether WAGO-1 has any role in chromatin-level silencing using ChIP-seq for silencing-associated histone marks in wago-1 mutants
Hypothesis: WAGO-1 may indirectly influence heterochromatin formation through its interaction with ZNFX-1 and nuclear Argonautes like HRDE-1
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