{"gene":"ANKRD52","run_date":"2026-06-09T22:02:43","timeline":{"discoveries":[{"year":2008,"finding":"ANKRD52 (PP6-ARS-C) is a regulatory subunit of the PP6 holoenzyme heterotrimer. It was identified by mass spectrometry as co-precipitating with FLAG-PP6R1 (a SAPS domain subunit). Tagged Ankrd28 (the closest paralog studied in detail) coprecipitated with PP6 catalytic subunit and with SAPS domain subunits PP6R1 and PP6R3. The C-terminal region of PP6R1 was sufficient to coprecipitate Ankrd28/Ankrd52-family proteins but not PP6 itself, demonstrating PP6R1 acts as a scaffold with separate binding regions for the catalytic subunit and the ankyrin repeat subunit. Endogenous PP6 holoenzymes with PP6R1 and PP6R3 eluted at >440 kDa from size-exclusion chromatography together with Ankrd28, consistent with a heterotrimer. Knockdown of PP6R1 or Ankrd28, but not PP6R3, enhanced IκBε degradation in response to TNFα, indicating functional specificity of the ankyrin repeat subunit.","method":"FLAG co-immunoprecipitation, mass spectrometry, size-exclusion chromatography, siRNA knockdown with IκBε degradation assay","journal":"Biochemistry","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal Co-IP, mass spectrometry, biochemical fractionation, and functional knockdown, all in one study; foundational characterization of the PP6 heterotrimer","pmids":["18186651"],"is_preprint":false},{"year":2017,"finding":"ANKRD52 is the regulatory subunit of the ANKRD52-PPP6C phosphatase complex that dephosphorylates AGO2 at a cluster of conserved residues (S824-S834). Target engagement by AGO2 triggers hierarchical multi-site phosphorylation by CSNK1A1, followed by rapid dephosphorylation by the ANKRD52-PPP6C complex. AGO2 phosphorylation at these residues inhibits target mRNA binding. Inactivation of this phosphorylation cycle globally impairs miRNA-mediated silencing. Non-phosphorylatable AGO2 shows a pronounced expansion of its transcriptome-wide target repertoire at steady-state, reducing the active AGO2 pool per target.","method":"CRISPR genome-wide loss-of-function screen, fluorescent miRNA reporter, biochemical/genetic epistasis, AGO2 phospho-site mutagenesis, AGO2 CLIP-seq (transcriptome-wide binding profiling)","journal":"Nature","confidence":"High","confidence_rationale":"Tier 1-2 / Strong — CRISPR screen plus biochemical validation plus mutagenesis plus transcriptome-wide binding profiling; mechanistically rigorous single study establishing the phosphorylation cycle","pmids":["28114302"],"is_preprint":false},{"year":2020,"finding":"TAZ transcriptionally represses ANKRD52: knockdown of TAZ leads to enhanced ANKRD52 promoter activity and increased ANKRD52 mRNA levels. ANKRD52, as a subunit of the PP6 holoenzyme, interacts with PAK1 (identified by mass spectrometry). Knockdown of ANKRD52 or PP6c results in elevated PAK1 phosphorylation, while forced ANKRD52 expression attenuates cell mobility. ANKRD52 thus regulates cell migration through PP6c-mediated dephosphorylation of PAK1.","method":"TAZ siRNA knockdown with ANKRD52 promoter-reporter assay, mass spectrometry (ANKRD52-PP6c-PAK1 interaction), siRNA knockdown of ANKRD52/PP6c with PAK1 phosphorylation readout, cell mobility assay with ANKRD52 overexpression","journal":"Biochimica et biophysica acta. Molecular cell research","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — single lab, multiple orthogonal methods (promoter assay, MS, phosphorylation assay, functional mobility assay), but not independently replicated","pmids":["33096142"],"is_preprint":false},{"year":2021,"finding":"Genetic inactivation of ANKRD52, or re-introduction of frequent ANKRD52 patient mutations found in cancers, dampens JAK-STAT-interferon-γ signaling and antigen presentation in cancer cells, largely by abolishing miR-155-targeted silencing of SOCS1. This was established by combining CRISPR library screens in syngeneic mouse tumor models with co-culture systems under immune pressure, demonstrating that the ANKRD52-containing miRNA machinery maintains cancer cell sensitivity to T cell-mediated cytotoxicity.","method":"CRISPR library screen in syngeneic mouse tumor model, co-culture system with T cells, ANKRD52 patient-mutation re-introduction, JAK-STAT pathway and antigen presentation readouts, miR-155/SOCS1 epistasis","journal":"Nature communications","confidence":"High","confidence_rationale":"Tier 2 / Strong — CRISPR functional screen with patient mutation validation and epistasis to miR-155/SOCS1 axis, multiple orthogonal approaches in one study","pmids":["34853298"],"is_preprint":false},{"year":2024,"finding":"In colorectal cancer, PP6 functions as a heterotrimer comprising PP6c, PP6R subunits (PP6R1-3), and scaffold subunits including ANKRD52. The PP6c-PP6R3 complex (not specifically ANKRD52) was identified as a key player in regulating cancer stem cell markers; PP6c knockdown decreased colony-forming ability and in vivo proliferation. This study confirms the heterotrimer model for PP6 assembly including ANKRD52 as a scaffold subunit.","method":"siRNA knockdown of PP6c, colony formation assay, in vivo xenograft, transcriptome analysis of stemness genes","journal":"Cancer science","confidence":"Low","confidence_rationale":"Tier 3 / Weak — ANKRD52's specific role in this study is limited to confirming its membership in the PP6 heterotrimer; functional knockdown data focuses on PP6c and PP6R3, not ANKRD52 directly","pmids":["39014521"],"is_preprint":false}],"current_model":"ANKRD52 is a regulatory/scaffold subunit of the PP6 heterotrimer (PP6c catalytic subunit + SAPS-domain PP6R subunit + ANKRD52), where it binds the C-terminal region of PP6R1/R3 and confers substrate specificity; the best-characterized substrate is AGO2, which is phosphorylated at S824-S834 by CSNK1A1 upon target engagement and then rapidly dephosphorylated by the ANKRD52-PPP6C complex to maintain the global efficiency of miRNA-mediated silencing; ANKRD52-PP6 also dephosphorylates PAK1 to regulate cell migration, and this complex is transcriptionally suppressed by TAZ; additionally, loss of ANKRD52 function impairs miR-155-mediated silencing of SOCS1, dampening JAK-STAT/interferon-γ signaling and enabling cancer cells to evade T cell-mediated cytotoxicity."},"narrative":{"mechanistic_narrative":"ANKRD52 is the ankyrin-repeat regulatory subunit of the protein phosphatase 6 (PP6) heterotrimer, where it assembles with the PP6 catalytic subunit and a SAPS-domain PP6R subunit to confer substrate specificity on the complex [PMID:18186651]. It was identified by mass spectrometry as a PP6 holoenzyme component, binding the C-terminal scaffold region of PP6R1, which holds separate docking sites for the catalytic and ankyrin-repeat subunits, with endogenous holoenzymes eluting as >440 kDa heterotrimers [PMID:18186651]. Functionally, the ANKRD52-PP6 complex maintains the global efficiency of miRNA-mediated silencing by dephosphorylating AGO2 at a conserved S824-S834 cluster; target engagement triggers hierarchical phosphorylation of AGO2 by CSNK1A1, and rapid dephosphorylation by ANKRD52-PPP6C resets AGO2 for productive target binding, with loss of this cycle expanding the AGO2 target repertoire and diluting the active phosphatase-reset pool per target [PMID:28114302]. The same complex dephosphorylates PAK1 to restrain cell migration, and ANKRD52 transcription is repressed by TAZ [PMID:33096142]. Through its control of miRNA silencing, ANKRD52 sustains miR-155-mediated repression of SOCS1, so its inactivation—or reintroduction of cancer patient mutations—dampens JAK-STAT/interferon-γ signaling and antigen presentation, allowing tumor cells to evade T cell-mediated cytotoxicity [PMID:34853298].","teleology":[{"year":2008,"claim":"Established that ANKRD52 is not a free-standing protein but an integral ankyrin-repeat regulatory subunit of the PP6 phosphatase heterotrimer, defining the architecture in which a SAPS-domain subunit scaffolds the catalytic and ankyrin-repeat subunits.","evidence":"FLAG Co-IP, mass spectrometry, size-exclusion chromatography and siRNA knockdown with IκBε degradation readout","pmids":["18186651"],"confidence":"High","gaps":["Direct functional role of ANKRD52 itself (vs paralog Ankrd28) was inferred from family behavior","No substrate of the ANKRD52-PP6 complex identified at this stage","Structural basis of substrate-specificity conferred by the ankyrin repeats unresolved"]},{"year":2017,"claim":"Answered what physiological substrate the ANKRD52-PP6 complex acts on, showing it dephosphorylates AGO2 to sustain global miRNA silencing through a CSNK1A1-driven phosphorylation/dephosphorylation cycle.","evidence":"Genome-wide CRISPR loss-of-function screen, miRNA fluorescent reporter, AGO2 phospho-site mutagenesis and transcriptome-wide AGO2 CLIP-seq","pmids":["28114302"],"confidence":"High","gaps":["Structural detail of how ANKRD52 recognizes the AGO2 phospho-cluster not resolved","Whether ANKRD52 directs other PP6 substrates beyond AGO2 not addressed here"]},{"year":2020,"claim":"Extended the substrate range and added upstream regulation, showing ANKRD52-PP6 dephosphorylates PAK1 to limit migration and that TAZ transcriptionally represses ANKRD52.","evidence":"TAZ knockdown with ANKRD52 promoter-reporter, mass spectrometry, PAK1 phosphorylation assay and cell mobility assay with ANKRD52 overexpression","pmids":["33096142"],"confidence":"Medium","gaps":["Single-lab findings not independently replicated","Direct vs indirect dephosphorylation of PAK1 by the complex not fully separated","Mechanism of TAZ-mediated promoter repression not defined"]},{"year":2021,"claim":"Connected ANKRD52's role in miRNA silencing to tumor immune evasion, showing its loss disrupts miR-155 repression of SOCS1 and thereby dampens interferon-γ responsiveness and T cell killing.","evidence":"CRISPR library screen in syngeneic mouse tumors, T cell co-culture under immune pressure, patient-mutation reintroduction and miR-155/SOCS1 epistasis","pmids":["34853298"],"confidence":"High","gaps":["Whether AGO2 dephosphorylation is the specific node linking ANKRD52 to miR-155 function not directly demonstrated","Clinical relevance of specific patient mutations to phosphatase activity not biochemically dissected"]},{"year":2024,"claim":"Reaffirmed the PP6 heterotrimer model including ANKRD52 as a scaffold subunit in colorectal cancer, while attributing the stemness phenotype primarily to PP6c-PP6R3.","evidence":"siRNA knockdown of PP6c, colony formation assay, in vivo xenograft and stemness-gene transcriptome analysis","pmids":["39014521"],"confidence":"Low","gaps":["ANKRD52's specific contribution not tested; functional data focus on PP6c and PP6R3","No direct ANKRD52 knockdown or substrate assay in this context"]},{"year":null,"claim":"How ANKRD52's ankyrin repeats structurally select among PP6 substrates (AGO2, PAK1) and whether additional substrates couple it to other pathways remains unresolved.","evidence":"","pmids":[],"confidence":"Low","gaps":["No structure of ANKRD52 within the PP6 holoenzyme or bound to substrate","Substrate-selection rules conferred by the ankyrin-repeat subunit undefined","Tissue-specific and physiological scope of ANKRD52-PP6 substrates incomplete"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0140096","term_label":"catalytic activity, acting on a protein","supporting_discovery_ids":[1,2]},{"term_id":"GO:0098772","term_label":"molecular function regulator activity","supporting_discovery_ids":[0,1]},{"term_id":"GO:0060090","term_label":"molecular adaptor activity","supporting_discovery_ids":[0]}],"localization":[],"pathway":[{"term_id":"R-HSA-8953854","term_label":"Metabolism of RNA","supporting_discovery_ids":[1]},{"term_id":"R-HSA-168256","term_label":"Immune System","supporting_discovery_ids":[3]}],"complexes":["PP6 phosphatase heterotrimer"],"partners":["PPP6C","PP6R1","PP6R3","AGO2","PAK1","CSNK1A1"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q8NB46","full_name":"Serine/threonine-protein phosphatase 6 regulatory ankyrin repeat subunit C","aliases":["Ankyrin repeat domain-containing protein 52"],"length_aa":1076,"mass_kda":115.1,"function":"Putative regulatory subunit of protein phosphatase 6 (PP6) that may be involved in the recognition of phosphoprotein substrates","subcellular_location":"","url":"https://www.uniprot.org/uniprotkb/Q8NB46/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/ANKRD52","classification":"Not Classified","n_dependent_lines":210,"n_total_lines":1208,"dependency_fraction":0.173841059602649},"opencell":{"profiled":true,"resolved_as":"","ensg_id":"ENSG00000139645","cell_line_id":"CID001391","localizations":[{"compartment":"cytoplasmic","grade":3},{"compartment":"nucleoplasm","grade":1}],"interactors":[{"gene":"PPP6R3","stoichiometry":10.0},{"gene":"PPP6C","stoichiometry":10.0},{"gene":"ANKRD28","stoichiometry":4.0},{"gene":"PPP6R2","stoichiometry":4.0},{"gene":"PPP6R1","stoichiometry":0.2},{"gene":"CDK4","stoichiometry":0.2}],"url":"https://opencell.sf.czbiohub.org/target/CID001391","total_profiled":1310},"omim":[{"mim_id":"620862","title":"ANKYRIN REPEAT DOMAIN-CONTAINING PROTEIN 52; ANKRD52","url":"https://www.omim.org/entry/620862"},{"mim_id":"606229","title":"ARGONAUTE RISC COMPONENT 2; AGO2","url":"https://www.omim.org/entry/606229"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Approved","locations":[{"location":"Nucleoplasm","reliability":"Approved"},{"location":"Mitochondria","reliability":"Approved"}],"tissue_specificity":"Low tissue specificity","tissue_distribution":"Detected in all","driving_tissues":[],"url":"https://www.proteinatlas.org/search/ANKRD52"},"hgnc":{"alias_symbol":["FLJ34236","PP6-ARS-C"],"prev_symbol":[]},"alphafold":{"accession":"Q8NB46","domains":[{"cath_id":"1.25.40.20","chopping":"824-918","consensus_level":"medium","plddt":92.3923,"start":824,"end":918},{"cath_id":"1.25.40.20","chopping":"936-1015","consensus_level":"high","plddt":88.6504,"start":936,"end":1015}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q8NB46","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q8NB46-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q8NB46-F1-predicted_aligned_error_v6.png","plddt_mean":85.62},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=ANKRD52","jax_strain_url":"https://www.jax.org/strain/search?query=ANKRD52"},"sequence":{"accession":"Q8NB46","fasta_url":"https://rest.uniprot.org/uniprotkb/Q8NB46.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q8NB46/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q8NB46"}},"corpus_meta":[{"pmid":"24035497","id":"PMC_24035497","title":"Circular intronic long noncoding RNAs.","date":"2013","source":"Molecular cell","url":"https://pubmed.ncbi.nlm.nih.gov/24035497","citation_count":1879,"is_preprint":false},{"pmid":"28114302","id":"PMC_28114302","title":"An Argonaute phosphorylation cycle promotes microRNA-mediated silencing.","date":"2017","source":"Nature","url":"https://pubmed.ncbi.nlm.nih.gov/28114302","citation_count":204,"is_preprint":false},{"pmid":"18186651","id":"PMC_18186651","title":"Protein phosphatase 6 regulatory subunits composed of ankyrin repeat domains.","date":"2008","source":"Biochemistry","url":"https://pubmed.ncbi.nlm.nih.gov/18186651","citation_count":96,"is_preprint":false},{"pmid":"34453665","id":"PMC_34453665","title":"Linking circular intronic RNA degradation and function in transcription by RNase H1.","date":"2021","source":"Science China. 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Molecular cell research","url":"https://pubmed.ncbi.nlm.nih.gov/33096142","citation_count":9,"is_preprint":false},{"pmid":"39014521","id":"PMC_39014521","title":"Protein phosphatase 6 promotes stemness of colorectal cancer cells.","date":"2024","source":"Cancer science","url":"https://pubmed.ncbi.nlm.nih.gov/39014521","citation_count":4,"is_preprint":false},{"pmid":"37762595","id":"PMC_37762595","title":"PLK1 Regulates MicroRNA Biogenesis through Drosha Phosphorylation.","date":"2023","source":"International journal of molecular sciences","url":"https://pubmed.ncbi.nlm.nih.gov/37762595","citation_count":2,"is_preprint":false},{"pmid":"40069305","id":"PMC_40069305","title":"An exploratory study of high-throughput transcriptomic analysis reveals novel mRNA biomarkers for acute myocardial infarction using integrated methods.","date":"2025","source":"Scientific reports","url":"https://pubmed.ncbi.nlm.nih.gov/40069305","citation_count":2,"is_preprint":false},{"pmid":"40646730","id":"PMC_40646730","title":"Genome-Wide Association Study for Weight-Related Traits in Scylla paramamosain Using Whole-Genome Resequencing.","date":"2025","source":"Animals : an open access journal from MDPI","url":"https://pubmed.ncbi.nlm.nih.gov/40646730","citation_count":2,"is_preprint":false},{"pmid":"38296907","id":"PMC_38296907","title":"Clinical and Immunological Significance of ANKRD52 in Pan-Cancer.","date":"2024","source":"Biochemical genetics","url":"https://pubmed.ncbi.nlm.nih.gov/38296907","citation_count":0,"is_preprint":false},{"pmid":"40993657","id":"PMC_40993657","title":"Proteomic profiling identifies miR-423-5p as a modulator of oncogenic metabolism in HCC.","date":"2025","source":"Journal of translational medicine","url":"https://pubmed.ncbi.nlm.nih.gov/40993657","citation_count":0,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":11065,"output_tokens":1999,"usd":0.03159,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":9003,"output_tokens":2581,"usd":0.05477,"stage2_stop_reason":"end_turn"},"total_usd":0.08636,"stage1_batch_id":"msgbatch_0179Z2pxRYBsXi2xADneafRw","stage2_batch_id":"msgbatch_01LaY9ZaVdgjWArcZo9eqQE5","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2008,\n      \"finding\": \"ANKRD52 (PP6-ARS-C) is a regulatory subunit of the PP6 holoenzyme heterotrimer. It was identified by mass spectrometry as co-precipitating with FLAG-PP6R1 (a SAPS domain subunit). Tagged Ankrd28 (the closest paralog studied in detail) coprecipitated with PP6 catalytic subunit and with SAPS domain subunits PP6R1 and PP6R3. The C-terminal region of PP6R1 was sufficient to coprecipitate Ankrd28/Ankrd52-family proteins but not PP6 itself, demonstrating PP6R1 acts as a scaffold with separate binding regions for the catalytic subunit and the ankyrin repeat subunit. Endogenous PP6 holoenzymes with PP6R1 and PP6R3 eluted at >440 kDa from size-exclusion chromatography together with Ankrd28, consistent with a heterotrimer. Knockdown of PP6R1 or Ankrd28, but not PP6R3, enhanced IκBε degradation in response to TNFα, indicating functional specificity of the ankyrin repeat subunit.\",\n      \"method\": \"FLAG co-immunoprecipitation, mass spectrometry, size-exclusion chromatography, siRNA knockdown with IκBε degradation assay\",\n      \"journal\": \"Biochemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal Co-IP, mass spectrometry, biochemical fractionation, and functional knockdown, all in one study; foundational characterization of the PP6 heterotrimer\",\n      \"pmids\": [\"18186651\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"ANKRD52 is the regulatory subunit of the ANKRD52-PPP6C phosphatase complex that dephosphorylates AGO2 at a cluster of conserved residues (S824-S834). Target engagement by AGO2 triggers hierarchical multi-site phosphorylation by CSNK1A1, followed by rapid dephosphorylation by the ANKRD52-PPP6C complex. AGO2 phosphorylation at these residues inhibits target mRNA binding. Inactivation of this phosphorylation cycle globally impairs miRNA-mediated silencing. Non-phosphorylatable AGO2 shows a pronounced expansion of its transcriptome-wide target repertoire at steady-state, reducing the active AGO2 pool per target.\",\n      \"method\": \"CRISPR genome-wide loss-of-function screen, fluorescent miRNA reporter, biochemical/genetic epistasis, AGO2 phospho-site mutagenesis, AGO2 CLIP-seq (transcriptome-wide binding profiling)\",\n      \"journal\": \"Nature\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 / Strong — CRISPR screen plus biochemical validation plus mutagenesis plus transcriptome-wide binding profiling; mechanistically rigorous single study establishing the phosphorylation cycle\",\n      \"pmids\": [\"28114302\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"TAZ transcriptionally represses ANKRD52: knockdown of TAZ leads to enhanced ANKRD52 promoter activity and increased ANKRD52 mRNA levels. ANKRD52, as a subunit of the PP6 holoenzyme, interacts with PAK1 (identified by mass spectrometry). Knockdown of ANKRD52 or PP6c results in elevated PAK1 phosphorylation, while forced ANKRD52 expression attenuates cell mobility. ANKRD52 thus regulates cell migration through PP6c-mediated dephosphorylation of PAK1.\",\n      \"method\": \"TAZ siRNA knockdown with ANKRD52 promoter-reporter assay, mass spectrometry (ANKRD52-PP6c-PAK1 interaction), siRNA knockdown of ANKRD52/PP6c with PAK1 phosphorylation readout, cell mobility assay with ANKRD52 overexpression\",\n      \"journal\": \"Biochimica et biophysica acta. Molecular cell research\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — single lab, multiple orthogonal methods (promoter assay, MS, phosphorylation assay, functional mobility assay), but not independently replicated\",\n      \"pmids\": [\"33096142\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"Genetic inactivation of ANKRD52, or re-introduction of frequent ANKRD52 patient mutations found in cancers, dampens JAK-STAT-interferon-γ signaling and antigen presentation in cancer cells, largely by abolishing miR-155-targeted silencing of SOCS1. This was established by combining CRISPR library screens in syngeneic mouse tumor models with co-culture systems under immune pressure, demonstrating that the ANKRD52-containing miRNA machinery maintains cancer cell sensitivity to T cell-mediated cytotoxicity.\",\n      \"method\": \"CRISPR library screen in syngeneic mouse tumor model, co-culture system with T cells, ANKRD52 patient-mutation re-introduction, JAK-STAT pathway and antigen presentation readouts, miR-155/SOCS1 epistasis\",\n      \"journal\": \"Nature communications\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — CRISPR functional screen with patient mutation validation and epistasis to miR-155/SOCS1 axis, multiple orthogonal approaches in one study\",\n      \"pmids\": [\"34853298\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"In colorectal cancer, PP6 functions as a heterotrimer comprising PP6c, PP6R subunits (PP6R1-3), and scaffold subunits including ANKRD52. The PP6c-PP6R3 complex (not specifically ANKRD52) was identified as a key player in regulating cancer stem cell markers; PP6c knockdown decreased colony-forming ability and in vivo proliferation. This study confirms the heterotrimer model for PP6 assembly including ANKRD52 as a scaffold subunit.\",\n      \"method\": \"siRNA knockdown of PP6c, colony formation assay, in vivo xenograft, transcriptome analysis of stemness genes\",\n      \"journal\": \"Cancer science\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — ANKRD52's specific role in this study is limited to confirming its membership in the PP6 heterotrimer; functional knockdown data focuses on PP6c and PP6R3, not ANKRD52 directly\",\n      \"pmids\": [\"39014521\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"ANKRD52 is a regulatory/scaffold subunit of the PP6 heterotrimer (PP6c catalytic subunit + SAPS-domain PP6R subunit + ANKRD52), where it binds the C-terminal region of PP6R1/R3 and confers substrate specificity; the best-characterized substrate is AGO2, which is phosphorylated at S824-S834 by CSNK1A1 upon target engagement and then rapidly dephosphorylated by the ANKRD52-PPP6C complex to maintain the global efficiency of miRNA-mediated silencing; ANKRD52-PP6 also dephosphorylates PAK1 to regulate cell migration, and this complex is transcriptionally suppressed by TAZ; additionally, loss of ANKRD52 function impairs miR-155-mediated silencing of SOCS1, dampening JAK-STAT/interferon-γ signaling and enabling cancer cells to evade T cell-mediated cytotoxicity.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"ANKRD52 is the ankyrin-repeat regulatory subunit of the protein phosphatase 6 (PP6) heterotrimer, where it assembles with the PP6 catalytic subunit and a SAPS-domain PP6R subunit to confer substrate specificity on the complex [#0]. It was identified by mass spectrometry as a PP6 holoenzyme component, binding the C-terminal scaffold region of PP6R1, which holds separate docking sites for the catalytic and ankyrin-repeat subunits, with endogenous holoenzymes eluting as >440 kDa heterotrimers [#0]. Functionally, the ANKRD52-PP6 complex maintains the global efficiency of miRNA-mediated silencing by dephosphorylating AGO2 at a conserved S824-S834 cluster; target engagement triggers hierarchical phosphorylation of AGO2 by CSNK1A1, and rapid dephosphorylation by ANKRD52-PPP6C resets AGO2 for productive target binding, with loss of this cycle expanding the AGO2 target repertoire and diluting the active phosphatase-reset pool per target [#1]. The same complex dephosphorylates PAK1 to restrain cell migration, and ANKRD52 transcription is repressed by TAZ [#2]. Through its control of miRNA silencing, ANKRD52 sustains miR-155-mediated repression of SOCS1, so its inactivation—or reintroduction of cancer patient mutations—dampens JAK-STAT/interferon-\\u03b3 signaling and antigen presentation, allowing tumor cells to evade T cell-mediated cytotoxicity [#3].\",\n  \"teleology\": [\n    {\n      \"year\": 2008,\n      \"claim\": \"Established that ANKRD52 is not a free-standing protein but an integral ankyrin-repeat regulatory subunit of the PP6 phosphatase heterotrimer, defining the architecture in which a SAPS-domain subunit scaffolds the catalytic and ankyrin-repeat subunits.\",\n      \"evidence\": \"FLAG Co-IP, mass spectrometry, size-exclusion chromatography and siRNA knockdown with I\\u03baB\\u03b5 degradation readout\",\n      \"pmids\": [\"18186651\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"Direct functional role of ANKRD52 itself (vs paralog Ankrd28) was inferred from family behavior\",\n        \"No substrate of the ANKRD52-PP6 complex identified at this stage\",\n        \"Structural basis of substrate-specificity conferred by the ankyrin repeats unresolved\"\n      ]\n    },\n    {\n      \"year\": 2017,\n      \"claim\": \"Answered what physiological substrate the ANKRD52-PP6 complex acts on, showing it dephosphorylates AGO2 to sustain global miRNA silencing through a CSNK1A1-driven phosphorylation/dephosphorylation cycle.\",\n      \"evidence\": \"Genome-wide CRISPR loss-of-function screen, miRNA fluorescent reporter, AGO2 phospho-site mutagenesis and transcriptome-wide AGO2 CLIP-seq\",\n      \"pmids\": [\"28114302\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"Structural detail of how ANKRD52 recognizes the AGO2 phospho-cluster not resolved\",\n        \"Whether ANKRD52 directs other PP6 substrates beyond AGO2 not addressed here\"\n      ]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Extended the substrate range and added upstream regulation, showing ANKRD52-PP6 dephosphorylates PAK1 to limit migration and that TAZ transcriptionally represses ANKRD52.\",\n      \"evidence\": \"TAZ knockdown with ANKRD52 promoter-reporter, mass spectrometry, PAK1 phosphorylation assay and cell mobility assay with ANKRD52 overexpression\",\n      \"pmids\": [\"33096142\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Single-lab findings not independently replicated\",\n        \"Direct vs indirect dephosphorylation of PAK1 by the complex not fully separated\",\n        \"Mechanism of TAZ-mediated promoter repression not defined\"\n      ]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"Connected ANKRD52's role in miRNA silencing to tumor immune evasion, showing its loss disrupts miR-155 repression of SOCS1 and thereby dampens interferon-\\u03b3 responsiveness and T cell killing.\",\n      \"evidence\": \"CRISPR library screen in syngeneic mouse tumors, T cell co-culture under immune pressure, patient-mutation reintroduction and miR-155/SOCS1 epistasis\",\n      \"pmids\": [\"34853298\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"Whether AGO2 dephosphorylation is the specific node linking ANKRD52 to miR-155 function not directly demonstrated\",\n        \"Clinical relevance of specific patient mutations to phosphatase activity not biochemically dissected\"\n      ]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Reaffirmed the PP6 heterotrimer model including ANKRD52 as a scaffold subunit in colorectal cancer, while attributing the stemness phenotype primarily to PP6c-PP6R3.\",\n      \"evidence\": \"siRNA knockdown of PP6c, colony formation assay, in vivo xenograft and stemness-gene transcriptome analysis\",\n      \"pmids\": [\"39014521\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\n        \"ANKRD52's specific contribution not tested; functional data focus on PP6c and PP6R3\",\n        \"No direct ANKRD52 knockdown or substrate assay in this context\"\n      ]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How ANKRD52's ankyrin repeats structurally select among PP6 substrates (AGO2, PAK1) and whether additional substrates couple it to other pathways remains unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\n        \"No structure of ANKRD52 within the PP6 holoenzyme or bound to substrate\",\n        \"Substrate-selection rules conferred by the ankyrin-repeat subunit undefined\",\n        \"Tissue-specific and physiological scope of ANKRD52-PP6 substrates incomplete\"\n      ]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0140096\", \"supporting_discovery_ids\": [1, 2]},\n      {\"term_id\": \"GO:0098772\", \"supporting_discovery_ids\": [0, 1]},\n      {\"term_id\": \"GO:0060090\", \"supporting_discovery_ids\": [0]}\n    ],\n    \"localization\": [],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-8953854\", \"supporting_discovery_ids\": [1]},\n      {\"term_id\": \"R-HSA-168256\", \"supporting_discovery_ids\": [3]}\n    ],\n    \"complexes\": [\"PP6 phosphatase heterotrimer\"],\n    \"partners\": [\"PPP6C\", \"PP6R1\", \"PP6R3\", \"AGO2\", \"PAK1\", \"CSNK1A1\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":5,"faith_total":5,"faith_pct":100.0}}