{"gene":"PRIM2","run_date":"2026-06-10T06:43:35","timeline":{"discoveries":[{"year":1995,"finding":"PRIM2 (p58 subunit) is a component of the human DNA primase heterodimer (p49/p58), which catalyzes synthesis of oligoribonucleotide primers essential for initiation of DNA replication and Okazaki fragment synthesis during lagging strand replication.","method":"Chromosomal mapping and biochemical characterization of primase subunit composition","journal":"Genomics","confidence":"High","confidence_rationale":"Tier 1 / Strong — well-established biochemical function of primase complex with multiple orthogonal lines of evidence replicated across the field","pmids":["8530050"],"is_preprint":false},{"year":2022,"finding":"PRIM2 expression is regulated by the p53/RB pathway in lung cancer cells: mutation or deletion of p53 increases PRIM2 expression, and the transcription factor E2F (whose cellular localization is controlled by the p53/RB pathway) positively correlates with PRIM2 expression. Knockdown of PRIM2 induces cell cycle arrest, increases DNA damage, and increases cellular senescence, reducing lung cancer cell proliferation.","method":"siRNA knockdown of PRIM2 with cell cycle analysis, DNA damage markers, senescence assays; database analysis of E2F/CDK correlation; p53 mutation/deletion in cell lines with Western blot","journal":"Cancers","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — clean KD with defined cellular phenotypes and pathway placement via p53/RB/E2F; single lab, multiple orthogonal assays","pmids":["35884433"],"is_preprint":false},{"year":2020,"finding":"Loss of PRIM2 in lung cancer cells reduces GSH levels, increases cellular lipid ROS and mitochondrial MDA, and downregulates SLC7A11 and β-catenin expression, thereby inducing ferroptosis and inhibiting proliferation.","method":"siRNA knockdown of PRIM2, GSH measurement, lipid ROS and MDA assays, Western blot for SLC7A11 and β-catenin, colony formation assay, in vivo xenograft","journal":"OncoTargets and therapy","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — KD with multiple orthogonal biochemical readouts and in vivo confirmation; single lab","pmids":["33149601"],"is_preprint":false},{"year":2024,"finding":"PRIM2 physically interacts with FAM111B (by Co-IP) and upregulates FAM111B at both the RNA and protein stability level; this PRIM2/FAM111B axis promotes proliferation and migration in pancreatic ductal adenocarcinoma by modulating PI3K/AKT signaling and EMT markers.","method":"Co-immunoprecipitation, protein stability assays, Western blot, RT-qPCR, cell proliferation/migration assays, xenograft model","journal":"Medical oncology","confidence":"Medium","confidence_rationale":"Tier 2–3 / Moderate — Co-IP establishes interaction, protein stability and RNA assays are orthogonal; single lab","pmids":["39556158"],"is_preprint":false},{"year":2026,"finding":"LARS (Leucyl-tRNA synthetase) promotes PRIM2 protein synthesis through leucine-dependent translational control (SILAC-based measurement of leucine-dependent PRIM2 synthesis), activating DNA replication and cell cycle progression in osteosarcoma cells.","method":"SILAC stable isotope labeling, transcriptome sequencing, proteomic profiling, LARS/PRIM2 overexpression and knockdown, MTT/colony/EdU/flow cytometry assays, xenograft model","journal":"Journal of experimental & clinical cancer research","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — SILAC directly measures leucine-dependent PRIM2 translation; multiple orthogonal functional assays; single lab","pmids":["41832550"],"is_preprint":false}],"current_model":"PRIM2 encodes the 58-kDa large subunit of the DNA primase heterodimer (with PRIM1/p49), catalyzing oligoribonucleotide primer synthesis to initiate DNA replication and Okazaki fragment synthesis; its expression is regulated by the p53/RB/E2F transcriptional axis and by leucine-dependent translational control via LARS, and it physically interacts with FAM111B to modulate PI3K/AKT and EMT signaling, while its loss triggers ferroptosis through downregulation of SLC7A11 and depletion of GSH."},"narrative":{"mechanistic_narrative":"PRIM2 encodes the 58-kDa large subunit of the human DNA primase heterodimer (p49/p58), which synthesizes oligoribonucleotide primers required to initiate DNA replication and Okazaki fragment synthesis during lagging-strand replication [PMID:8530050]. Consistent with this replicative role, PRIM2 expression is governed by the p53/RB/E2F axis—loss of p53 elevates PRIM2, E2F positively correlates with its expression, and PRIM2 depletion arrests the cell cycle, raises DNA damage, and drives senescence to curtail proliferation [PMID:35884433]. Its abundance is further set translationally, as leucyl-tRNA synthetase (LARS) promotes leucine-dependent PRIM2 protein synthesis to activate DNA replication and cell cycle progression [PMID:41832550]. Beyond replication, PRIM2 supports tumor cell survival and growth through additional routes: its loss depletes GSH and SLC7A11 and elevates lipid ROS, triggering ferroptosis [PMID:33149601], and it physically interacts with and stabilizes FAM111B to engage PI3K/AKT signaling and EMT [PMID:39556158].","teleology":[{"year":1995,"claim":"Established the core identity of PRIM2 by defining it as the p58 large subunit of the DNA primase heterodimer responsible for priming DNA synthesis.","evidence":"Chromosomal mapping and biochemical characterization of primase subunit composition","pmids":["8530050"],"confidence":"High","gaps":["Does not resolve the catalytic vs. regulatory contribution of p58 within the heterodimer","No structural detail on primer length control or polymerase handoff from this entry"]},{"year":2020,"claim":"Linked PRIM2 to redox/cell-death control, showing its loss induces ferroptosis rather than acting purely as a replicative housekeeping factor.","evidence":"siRNA knockdown in lung cancer cells with GSH, lipid ROS, MDA assays, SLC7A11/β-catenin Western blot, colony formation, and xenograft","pmids":["33149601"],"confidence":"Medium","gaps":["Mechanism connecting primase subunit loss to SLC7A11 downregulation is not defined","Single lab; whether ferroptosis is secondary to replication stress is unresolved"]},{"year":2022,"claim":"Placed PRIM2 within the p53/RB/E2F regulatory circuit and tied its depletion to cell cycle arrest, DNA damage, and senescence, explaining its proliferative role.","evidence":"siRNA knockdown with cell cycle/DNA damage/senescence assays plus p53 mutation/deletion analysis and E2F correlation in lung cancer cells","pmids":["35884433"],"confidence":"Medium","gaps":["Direct E2F binding to the PRIM2 promoter not demonstrated","Single lab; causal hierarchy between DNA damage and senescence not separated"]},{"year":2024,"claim":"Identified a physical PRIM2 partner (FAM111B), revealing a signaling function beyond replication via PI3K/AKT and EMT.","evidence":"Co-immunoprecipitation, protein stability and RT-qPCR assays, proliferation/migration assays, and xenograft in pancreatic ductal adenocarcinoma","pmids":["39556158"],"confidence":"Medium","gaps":["Single Co-IP without reciprocal/structural validation of the interaction interface","How PRIM2 stabilizes FAM111B mechanistically is unknown"]},{"year":2026,"claim":"Demonstrated translational control of PRIM2 by LARS, showing nutrient (leucine) availability gates PRIM2 synthesis and downstream DNA replication.","evidence":"SILAC measurement of leucine-dependent PRIM2 synthesis, transcriptome/proteome profiling, LARS/PRIM2 perturbation, and functional assays in osteosarcoma","pmids":["41832550"],"confidence":"Medium","gaps":["Molecular intermediary linking LARS leucine sensing to PRIM2 mRNA translation not identified","Single lab; generality across tissues untested"]},{"year":null,"claim":"How the canonical primase activity of PRIM2 mechanistically connects to its reported roles in ferroptosis suppression and PI3K/AKT-EMT signaling remains unresolved.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No structural model of PRIM2 in any human study within the corpus","Whether non-replicative phenotypes are direct or secondary to replication stress is unknown"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0140098","term_label":"catalytic activity, acting on RNA","supporting_discovery_ids":[0]}],"localization":[],"pathway":[{"term_id":"R-HSA-69306","term_label":"DNA Replication","supporting_discovery_ids":[0]},{"term_id":"R-HSA-1640170","term_label":"Cell Cycle","supporting_discovery_ids":[1]}],"complexes":["DNA primase (p49/p58 heterodimer)"],"partners":["PRIM1","FAM111B","LARS"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"P49643","full_name":"DNA primase large subunit","aliases":["DNA primase 58 kDa subunit","p58"],"length_aa":509,"mass_kda":58.8,"function":"Regulatory subunit of the DNA primase complex and component of the DNA polymerase alpha complex (also known as the alpha DNA polymerase-primase complex) which play an essential role in the initiation of DNA synthesis (PubMed:17893144, PubMed:25550159, PubMed:26975377, PubMed:9705292). During the S phase of the cell cycle, the DNA polymerase alpha complex (composed of a catalytic subunit POLA1, an accessory subunit POLA2 and two primase subunits, the catalytic subunit PRIM1 and the regulatory subunit PRIM2) is recruited to DNA at the replicative forks via direct interactions with MCM10 and WDHD1 (By similarity). The primase subunit of the polymerase alpha complex initiates DNA synthesis by oligomerising short RNA primers on both leading and lagging strands (PubMed:17893144). These primers are initially extended by the polymerase alpha catalytic subunit and subsequently transferred to polymerase delta and polymerase epsilon for processive synthesis on the lagging and leading strand, respectively (By similarity). In the primase complex, both subunits are necessary for the initial di-nucleotide formation, but the extension of the primer depends only on the catalytic subunit (PubMed:17893144, PubMed:25550159). Binds RNA:DNA duplex and coordinates the catalytic activities of PRIM1 and POLA2 during primase-to-polymerase switch","subcellular_location":"","url":"https://www.uniprot.org/uniprotkb/P49643/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":true,"resolved_as":"","url":"https://depmap.org/portal/gene/PRIM2","classification":"Common Essential","n_dependent_lines":74,"n_total_lines":74,"dependency_fraction":1.0},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[{"gene":"SSRP1","stoichiometry":0.2}],"url":"https://opencell.sf.czbiohub.org/search/PRIM2","total_profiled":1310},"omim":[{"mim_id":"176636","title":"PRIMASE POLYPEPTIDE 2A; PRIM2A","url":"https://www.omim.org/entry/176636"},{"mim_id":"176635","title":"PRIMASE POLYPEPTIDE 1; PRIM1","url":"https://www.omim.org/entry/176635"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Supported","locations":[{"location":"Nucleoplasm","reliability":"Supported"}],"tissue_specificity":"Tissue enhanced","tissue_distribution":"Detected in all","driving_tissues":[{"tissue":"prostate","ntpm":30.3}],"url":"https://www.proteinatlas.org/search/PRIM2"},"hgnc":{"alias_symbol":[],"prev_symbol":["PRIM2A"]},"alphafold":{"accession":"P49643","domains":[{"cath_id":"1.20.930.80","chopping":"19-136_222-255","consensus_level":"medium","plddt":87.7678,"start":19,"end":255},{"cath_id":"-","chopping":"143-218","consensus_level":"medium","plddt":84.0258,"start":143,"end":218},{"cath_id":"-","chopping":"275-457","consensus_level":"medium","plddt":91.5229,"start":275,"end":457}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/P49643","model_url":"https://alphafold.ebi.ac.uk/files/AF-P49643-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-P49643-F1-predicted_aligned_error_v6.png","plddt_mean":80.62},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=PRIM2","jax_strain_url":"https://www.jax.org/strain/search?query=PRIM2"},"sequence":{"accession":"P49643","fasta_url":"https://rest.uniprot.org/uniprotkb/P49643.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/P49643/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/P49643"}},"corpus_meta":[{"pmid":"33149601","id":"PMC_33149601","title":"Dihydroartemisinin Inhibits the Proliferation, Colony Formation and Induces Ferroptosis of Lung Cancer Cells by Inhibiting PRIM2/SLC7A11 Axis.","date":"2020","source":"OncoTargets and therapy","url":"https://pubmed.ncbi.nlm.nih.gov/33149601","citation_count":98,"is_preprint":false},{"pmid":"8530050","id":"PMC_8530050","title":"Assignment of the 49-kDa (PRIM1) and 58-kDa (PRIM2A and PRIM2B) subunit genes of the human DNA primase to chromosome bands 1q44 and 6p11.1-p12.","date":"1995","source":"Genomics","url":"https://pubmed.ncbi.nlm.nih.gov/8530050","citation_count":30,"is_preprint":false},{"pmid":"34139933","id":"PMC_34139933","title":"Curcumin restrains hepatocellular carcinoma progression depending on the regulation of the circ_0078710/miR-378b/PRIM2 axis.","date":"2021","source":"Journal of receptor and signal transduction research","url":"https://pubmed.ncbi.nlm.nih.gov/34139933","citation_count":23,"is_preprint":false},{"pmid":"34058013","id":"PMC_34058013","title":"Genetic variants of CHEK1, PRIM2 and CDK6 in the mitotic phase-related pathway are associated with nonsmall cell lung cancer survival.","date":"2021","source":"International journal of cancer","url":"https://pubmed.ncbi.nlm.nih.gov/34058013","citation_count":21,"is_preprint":false},{"pmid":"35884433","id":"PMC_35884433","title":"PRIM2 Promotes Cell Cycle and Tumor Progression in p53-Mutant Lung Cancer.","date":"2022","source":"Cancers","url":"https://pubmed.ncbi.nlm.nih.gov/35884433","citation_count":15,"is_preprint":false},{"pmid":"22437878","id":"PMC_22437878","title":"Lack of genomic imprinting of DNA primase, polypeptide 2 (PRIM2) in human term placenta and white blood cells.","date":"2012","source":"Epigenetics","url":"https://pubmed.ncbi.nlm.nih.gov/22437878","citation_count":12,"is_preprint":false},{"pmid":"39556158","id":"PMC_39556158","title":"PRIM2 promotes proliferation and metastasis of pancreatic ductal adenocarcinoma through interactions with FAM111B.","date":"2024","source":"Medical oncology (Northwood, London, England)","url":"https://pubmed.ncbi.nlm.nih.gov/39556158","citation_count":6,"is_preprint":false},{"pmid":"36685730","id":"PMC_36685730","title":"The primase subunits of DNA polymerase α, PRIM1 and PRIM2, are required for the replication of the geminivirus tomato yellow leaf curl virus in the host plant.","date":"2023","source":"microPublication biology","url":"https://pubmed.ncbi.nlm.nih.gov/36685730","citation_count":4,"is_preprint":false},{"pmid":"41832550","id":"PMC_41832550","title":"LARS promotes osteosarcoma proliferation through leucine-dependent PRIM2 translation and DNA replication activation.","date":"2026","source":"Journal of experimental & clinical cancer research : CR","url":"https://pubmed.ncbi.nlm.nih.gov/41832550","citation_count":0,"is_preprint":false},{"pmid":"41629253","id":"PMC_41629253","title":"Large deletions in the DNA primase large subunit PRIM2 are associated with NADP-malate dehydrogenase activity in a porcine F2 cross.","date":"2026","source":"Animal genetics","url":"https://pubmed.ncbi.nlm.nih.gov/41629253","citation_count":0,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":6870,"output_tokens":1308,"usd":0.020115,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":7980,"output_tokens":2013,"usd":0.045112,"stage2_stop_reason":"end_turn"},"total_usd":0.065227,"stage1_batch_id":"msgbatch_01CNoDbkChHEkgrJnL7BwtGJ","stage2_batch_id":"msgbatch_016Y4x9E9Wg5VQDANj9quSQD","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 1995,\n      \"finding\": \"PRIM2 (p58 subunit) is a component of the human DNA primase heterodimer (p49/p58), which catalyzes synthesis of oligoribonucleotide primers essential for initiation of DNA replication and Okazaki fragment synthesis during lagging strand replication.\",\n      \"method\": \"Chromosomal mapping and biochemical characterization of primase subunit composition\",\n      \"journal\": \"Genomics\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — well-established biochemical function of primase complex with multiple orthogonal lines of evidence replicated across the field\",\n      \"pmids\": [\"8530050\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"PRIM2 expression is regulated by the p53/RB pathway in lung cancer cells: mutation or deletion of p53 increases PRIM2 expression, and the transcription factor E2F (whose cellular localization is controlled by the p53/RB pathway) positively correlates with PRIM2 expression. Knockdown of PRIM2 induces cell cycle arrest, increases DNA damage, and increases cellular senescence, reducing lung cancer cell proliferation.\",\n      \"method\": \"siRNA knockdown of PRIM2 with cell cycle analysis, DNA damage markers, senescence assays; database analysis of E2F/CDK correlation; p53 mutation/deletion in cell lines with Western blot\",\n      \"journal\": \"Cancers\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — clean KD with defined cellular phenotypes and pathway placement via p53/RB/E2F; single lab, multiple orthogonal assays\",\n      \"pmids\": [\"35884433\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"Loss of PRIM2 in lung cancer cells reduces GSH levels, increases cellular lipid ROS and mitochondrial MDA, and downregulates SLC7A11 and β-catenin expression, thereby inducing ferroptosis and inhibiting proliferation.\",\n      \"method\": \"siRNA knockdown of PRIM2, GSH measurement, lipid ROS and MDA assays, Western blot for SLC7A11 and β-catenin, colony formation assay, in vivo xenograft\",\n      \"journal\": \"OncoTargets and therapy\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — KD with multiple orthogonal biochemical readouts and in vivo confirmation; single lab\",\n      \"pmids\": [\"33149601\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"PRIM2 physically interacts with FAM111B (by Co-IP) and upregulates FAM111B at both the RNA and protein stability level; this PRIM2/FAM111B axis promotes proliferation and migration in pancreatic ductal adenocarcinoma by modulating PI3K/AKT signaling and EMT markers.\",\n      \"method\": \"Co-immunoprecipitation, protein stability assays, Western blot, RT-qPCR, cell proliferation/migration assays, xenograft model\",\n      \"journal\": \"Medical oncology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2–3 / Moderate — Co-IP establishes interaction, protein stability and RNA assays are orthogonal; single lab\",\n      \"pmids\": [\"39556158\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2026,\n      \"finding\": \"LARS (Leucyl-tRNA synthetase) promotes PRIM2 protein synthesis through leucine-dependent translational control (SILAC-based measurement of leucine-dependent PRIM2 synthesis), activating DNA replication and cell cycle progression in osteosarcoma cells.\",\n      \"method\": \"SILAC stable isotope labeling, transcriptome sequencing, proteomic profiling, LARS/PRIM2 overexpression and knockdown, MTT/colony/EdU/flow cytometry assays, xenograft model\",\n      \"journal\": \"Journal of experimental & clinical cancer research\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — SILAC directly measures leucine-dependent PRIM2 translation; multiple orthogonal functional assays; single lab\",\n      \"pmids\": [\"41832550\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"PRIM2 encodes the 58-kDa large subunit of the DNA primase heterodimer (with PRIM1/p49), catalyzing oligoribonucleotide primer synthesis to initiate DNA replication and Okazaki fragment synthesis; its expression is regulated by the p53/RB/E2F transcriptional axis and by leucine-dependent translational control via LARS, and it physically interacts with FAM111B to modulate PI3K/AKT and EMT signaling, while its loss triggers ferroptosis through downregulation of SLC7A11 and depletion of GSH.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"PRIM2 encodes the 58-kDa large subunit of the human DNA primase heterodimer (p49/p58), which synthesizes oligoribonucleotide primers required to initiate DNA replication and Okazaki fragment synthesis during lagging-strand replication [#0]. Consistent with this replicative role, PRIM2 expression is governed by the p53/RB/E2F axis—loss of p53 elevates PRIM2, E2F positively correlates with its expression, and PRIM2 depletion arrests the cell cycle, raises DNA damage, and drives senescence to curtail proliferation [#1]. Its abundance is further set translationally, as leucyl-tRNA synthetase (LARS) promotes leucine-dependent PRIM2 protein synthesis to activate DNA replication and cell cycle progression [#4]. Beyond replication, PRIM2 supports tumor cell survival and growth through additional routes: its loss depletes GSH and SLC7A11 and elevates lipid ROS, triggering ferroptosis [#2], and it physically interacts with and stabilizes FAM111B to engage PI3K/AKT signaling and EMT [#3].\",\n  \"teleology\": [\n    {\n      \"year\": 1995,\n      \"claim\": \"Established the core identity of PRIM2 by defining it as the p58 large subunit of the DNA primase heterodimer responsible for priming DNA synthesis.\",\n      \"evidence\": \"Chromosomal mapping and biochemical characterization of primase subunit composition\",\n      \"pmids\": [\"8530050\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"Does not resolve the catalytic vs. regulatory contribution of p58 within the heterodimer\",\n        \"No structural detail on primer length control or polymerase handoff from this entry\"\n      ]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Linked PRIM2 to redox/cell-death control, showing its loss induces ferroptosis rather than acting purely as a replicative housekeeping factor.\",\n      \"evidence\": \"siRNA knockdown in lung cancer cells with GSH, lipid ROS, MDA assays, SLC7A11/β-catenin Western blot, colony formation, and xenograft\",\n      \"pmids\": [\"33149601\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Mechanism connecting primase subunit loss to SLC7A11 downregulation is not defined\",\n        \"Single lab; whether ferroptosis is secondary to replication stress is unresolved\"\n      ]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Placed PRIM2 within the p53/RB/E2F regulatory circuit and tied its depletion to cell cycle arrest, DNA damage, and senescence, explaining its proliferative role.\",\n      \"evidence\": \"siRNA knockdown with cell cycle/DNA damage/senescence assays plus p53 mutation/deletion analysis and E2F correlation in lung cancer cells\",\n      \"pmids\": [\"35884433\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Direct E2F binding to the PRIM2 promoter not demonstrated\",\n        \"Single lab; causal hierarchy between DNA damage and senescence not separated\"\n      ]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Identified a physical PRIM2 partner (FAM111B), revealing a signaling function beyond replication via PI3K/AKT and EMT.\",\n      \"evidence\": \"Co-immunoprecipitation, protein stability and RT-qPCR assays, proliferation/migration assays, and xenograft in pancreatic ductal adenocarcinoma\",\n      \"pmids\": [\"39556158\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Single Co-IP without reciprocal/structural validation of the interaction interface\",\n        \"How PRIM2 stabilizes FAM111B mechanistically is unknown\"\n      ]\n    },\n    {\n      \"year\": 2026,\n      \"claim\": \"Demonstrated translational control of PRIM2 by LARS, showing nutrient (leucine) availability gates PRIM2 synthesis and downstream DNA replication.\",\n      \"evidence\": \"SILAC measurement of leucine-dependent PRIM2 synthesis, transcriptome/proteome profiling, LARS/PRIM2 perturbation, and functional assays in osteosarcoma\",\n      \"pmids\": [\"41832550\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Molecular intermediary linking LARS leucine sensing to PRIM2 mRNA translation not identified\",\n        \"Single lab; generality across tissues untested\"\n      ]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How the canonical primase activity of PRIM2 mechanistically connects to its reported roles in ferroptosis suppression and PI3K/AKT-EMT signaling remains unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"No structural model of PRIM2 in any human study within the corpus\",\n        \"Whether non-replicative phenotypes are direct or secondary to replication stress is unknown\"\n      ]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0140098\", \"supporting_discovery_ids\": [0]}\n    ],\n    \"localization\": [],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-69306\", \"supporting_discovery_ids\": [0]},\n      {\"term_id\": \"R-HSA-1640170\", \"supporting_discovery_ids\": [1]}\n    ],\n    \"complexes\": [\"DNA primase (p49/p58 heterodimer)\"],\n    \"partners\": [\"PRIM1\", \"FAM111B\", \"LARS\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":4,"faith_total":4,"faith_pct":100.0}}