{"gene":"REEP4","run_date":"2026-06-10T06:43:36","timeline":{"discoveries":[{"year":2013,"finding":"REEP4 (and the closely related REEP3) localizes to the endoplasmic reticulum and binds microtubules via a short, positively charged amino acid sequence connecting its two hydrophobic domains; depletion of REEP3/4 from HeLa cells causes ER membranes to accumulate on metaphase chromosomes, demonstrating that REEP3/4 function redundantly to clear ER from metaphase chromatin and ensure correct mitotic progression.","method":"Biochemical screen for microtubule-membrane linkers, siRNA depletion in HeLa cells, live-cell imaging, domain mutagenesis (positively charged linker sequence)","journal":"Developmental Cell","confidence":"High","confidence_rationale":"Tier 2 / Strong — biochemical screen, domain mutagenesis, siRNA KD with defined mitotic phenotype, multiple orthogonal methods in one study","pmids":["23911198"],"is_preprint":false},{"year":2013,"finding":"Depletion of REEP3/4 in HeLa cells results in a proliferation of intranuclear membranes derived from the nuclear envelope, a defect that originates in mitosis when ER accumulates on chromosomes, establishing a causal link between REEP3/4 mitotic function and proper nuclear envelope architecture in daughter cells.","method":"siRNA depletion in HeLa cells, electron microscopy/fluorescence microscopy of nuclear envelope architecture","journal":"Developmental Cell","confidence":"High","confidence_rationale":"Tier 2 / Strong — loss-of-function with defined morphological phenotype, multiple orthogonal imaging methods, single rigorous study","pmids":["23911198"],"is_preprint":false},{"year":2019,"finding":"REEP3 and REEP4 promote ER tubulation during mitosis through their reticulon homology domains (RHDs), generating the high-curvature morphology of mitotic ER; this ER-shaping activity is mechanistically distinct from their previously described function in clearing ER from metaphase chromatin, and the REEP3/4 C-terminus mediates regulation of this activity.","method":"siRNA depletion in cultured cells, live-cell fluorescence and electron microscopy of ER morphology, domain analysis (RHD and C-terminus)","journal":"Molecular Biology of the Cell","confidence":"High","confidence_rationale":"Tier 2 / Strong — loss-of-function with defined ER morphology phenotype, domain dissection, orthogonal imaging methods, independent study replicating and extending REEP3/4 function","pmids":["30995177"],"is_preprint":false},{"year":2021,"finding":"REEP4 localizes not only to high-curvature cytoplasmic ER but is also recruited to the inner nuclear membrane by the NPC biogenesis factor ELYS; this inner-nuclear-membrane pool of REEP4 promotes nuclear pore complex (NPC) assembly, with a particular requirement during mitotic NPC biogenesis.","method":"Fluorescence microscopy (localization to inner nuclear membrane), Co-IP/interaction with ELYS, siRNA depletion with NPC assembly assay, mitotic NPC biogenesis assay","journal":"Journal of Cell Biology","confidence":"High","confidence_rationale":"Tier 2 / Moderate — reciprocal interaction with ELYS, defined subcellular localization with functional consequence, loss-of-function NPC assembly phenotype, multiple orthogonal methods in one study","pmids":["34874453"],"is_preprint":false},{"year":2011,"finding":"REEP4 contains a phosphorylated 14-3-3-binding site in its cytoplasmic domain; 14-3-3 proteins undergo physiological interaction with ER-tethered REEP4 in a phosphorylation-dependent manner.","method":"14-3-3 affinity purification, mass spectrometry phosphoproteomics, experimental validation of binding site","journal":"Molecular & Cellular Proteomics","confidence":"Medium","confidence_rationale":"Tier 3 / Moderate — phosphoproteomics with experimental validation of binding site, but mechanistic consequence not defined","pmids":["21725060"],"is_preprint":false},{"year":2009,"finding":"Morpholino-mediated knockdown of REEP4 in Xenopus tropicalis embryos causes a kinked body axis and paralysis, with normal early expression of neural and muscle markers that subsequently downregulate by tailbud stage, indicating REEP4 is required for maintenance of both the nervous system and musculature during early vertebrate development.","method":"Antisense morpholino oligonucleotide knockdown in Xenopus tropicalis, in situ hybridization/marker gene expression analysis","journal":"International Journal of Developmental Biology","confidence":"Medium","confidence_rationale":"Tier 2 / Weak — clean loss-of-function with defined developmental phenotype and marker analysis, single lab/study, no molecular mechanism identified","pmids":["19123125"],"is_preprint":false}],"current_model":"REEP4 is an ER membrane protein with a reticulon homology domain (RHD) that uses a positively charged linker between its two hydrophobic domains to bind microtubules and, together with REEP3, clears ER from metaphase chromosomes during mitosis; its RHD drives high-curvature ER tubulation specifically during mitosis; it is additionally recruited to the inner nuclear membrane by ELYS, where it promotes nuclear pore complex assembly particularly during mitotic NPC biogenesis; and its cytoplasmic domain contains a phosphorylation-dependent 14-3-3-binding site, placing it in a signaling nexus that coordinates ER morphogenesis, nuclear envelope reformation, and cell cycle progression."},"narrative":{"mechanistic_narrative":"REEP4 is an endoplasmic reticulum membrane protein that coordinates ER morphogenesis with mitotic progression and nuclear envelope organization [PMID:23911198, PMID:30995177]. Together with the closely related REEP3, it binds microtubules through a short positively charged sequence between its two hydrophobic domains and clears ER membranes from metaphase chromosomes; loss of REEP3/4 causes ER to accumulate on mitotic chromatin and produces aberrant intranuclear membranes in daughter cells [PMID:23911198]. Distinct from this clearance function, its reticulon homology domain drives the high-curvature ER tubulation characteristic of mitotic ER, with the C-terminus regulating this activity [PMID:30995177]. A separate pool of REEP4 is recruited to the inner nuclear membrane by the NPC biogenesis factor ELYS, where it promotes nuclear pore complex assembly, particularly during mitosis [PMID:34874453]. Its cytoplasmic domain carries a phosphorylation-dependent 14-3-3-binding site, linking REEP4 to phospho-regulatory signaling [PMID:21725060]. In vertebrate development, REEP4 is required to maintain nervous-system and muscle gene expression during early embryogenesis [PMID:19123125].","teleology":[{"year":2009,"claim":"Before any molecular role was assigned, it was unknown whether REEP4 was physiologically required in a whole organism; knockdown established an essential role in early vertebrate development.","evidence":"Antisense morpholino knockdown in Xenopus tropicalis with marker gene in situ analysis","pmids":["19123125"],"confidence":"Medium","gaps":["No molecular mechanism connecting REEP4 to neural/muscle maintenance","Phenotype from a single study with no rescue control reported"]},{"year":2011,"claim":"It was unknown how REEP4 might be regulated; phosphoproteomics identified a phosphorylation-dependent 14-3-3-binding site in its cytoplasmic domain, placing REEP4 under phospho-signaling control.","evidence":"14-3-3 affinity purification, MS phosphoproteomics, and binding-site validation","pmids":["21725060"],"confidence":"Medium","gaps":["Functional consequence of 14-3-3 binding undefined","Kinase responsible for the phosphorylation not identified"]},{"year":2013,"claim":"The cellular function of REEP4 was unresolved; a microtubule-membrane linker screen showed REEP3/4 bind microtubules via a positively charged linker and redundantly clear ER from metaphase chromatin, defining a role in mitotic ER positioning and downstream nuclear envelope integrity.","evidence":"Biochemical linker screen, siRNA depletion in HeLa cells, live imaging, EM, and domain mutagenesis","pmids":["23911198"],"confidence":"High","gaps":["Redundancy with REEP3 prevents assigning REEP4-specific contribution","How the linker engages microtubules structurally not resolved"]},{"year":2019,"claim":"It was unclear whether REEP3/4 only repositioned ER or also shaped it; RHD-dependent ER tubulation during mitosis was shown to be a function mechanistically distinct from chromatin clearance.","evidence":"siRNA depletion, live and electron microscopy of ER morphology, and RHD/C-terminus domain dissection","pmids":["30995177"],"confidence":"High","gaps":["Regulatory inputs governing the C-terminus-mediated control not defined","Relationship to the 14-3-3 site unexplored"]},{"year":2021,"claim":"Whether REEP4 acted beyond the cytoplasmic ER was unknown; recruitment to the inner nuclear membrane by ELYS revealed a direct role in nuclear pore complex assembly, especially during mitotic NPC biogenesis.","evidence":"Fluorescence localization, ELYS Co-IP, and siRNA depletion with NPC assembly assays","pmids":["34874453"],"confidence":"High","gaps":["Mechanism by which REEP4 promotes NPC assembly not defined","Whether ER-shaping and NPC-assembly pools are functionally separable unclear"]},{"year":null,"claim":"How REEP4's phospho-regulation, microtubule binding, ER-shaping, and ELYS-dependent NPC functions are integrated across the cell cycle remains unresolved.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No unified model linking 14-3-3 signaling to its mitotic functions","REEP4-specific roles separate from REEP3 redundancy not established","No structural model of the protein"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0008092","term_label":"cytoskeletal protein binding","supporting_discovery_ids":[0]},{"term_id":"GO:0005198","term_label":"structural molecule activity","supporting_discovery_ids":[2]}],"localization":[{"term_id":"GO:0005783","term_label":"endoplasmic reticulum","supporting_discovery_ids":[0,2]},{"term_id":"GO:0005635","term_label":"nuclear envelope","supporting_discovery_ids":[3]}],"pathway":[{"term_id":"R-HSA-1640170","term_label":"Cell Cycle","supporting_discovery_ids":[0,1,2]},{"term_id":"R-HSA-1852241","term_label":"Organelle biogenesis and maintenance","supporting_discovery_ids":[3]}],"complexes":[],"partners":["REEP3","ELYS","YWHAZ"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q9H6H4","full_name":"Receptor expression-enhancing protein 4","aliases":[],"length_aa":257,"mass_kda":29.4,"function":"Microtubule-binding protein required to ensure proper cell division and nuclear envelope reassembly by sequestering the endoplasmic reticulum away from chromosomes during mitosis. Probably acts by clearing the endoplasmic reticulum membrane from metaphase chromosomes","subcellular_location":"Endoplasmic reticulum membrane","url":"https://www.uniprot.org/uniprotkb/Q9H6H4/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/REEP4","classification":"Not Classified","n_dependent_lines":13,"n_total_lines":1208,"dependency_fraction":0.01076158940397351},"opencell":{"profiled":true,"resolved_as":"","ensg_id":"ENSG00000168476","cell_line_id":"CID001523","localizations":[{"compartment":"er","grade":3},{"compartment":"vesicles","grade":2}],"interactors":[{"gene":"REEP2","stoichiometry":10.0},{"gene":"RTN4","stoichiometry":4.0},{"gene":"ARL6IP1","stoichiometry":0.2},{"gene":"ATL3","stoichiometry":0.2},{"gene":"COPB2","stoichiometry":0.2},{"gene":"COPE","stoichiometry":0.2},{"gene":"RTN3","stoichiometry":0.2}],"url":"https://opencell.sf.czbiohub.org/target/CID001523","total_profiled":1310},"omim":[{"mim_id":"609349","title":"RECEPTOR EXPRESSION-ENHANCING PROTEIN 4; REEP4","url":"https://www.omim.org/entry/609349"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Supported","locations":[{"location":"Endoplasmic reticulum","reliability":"Supported"}],"tissue_specificity":"Tissue enhanced","tissue_distribution":"Detected in all","driving_tissues":[{"tissue":"esophagus","ntpm":90.4},{"tissue":"skin 1","ntpm":91.6}],"url":"https://www.proteinatlas.org/search/REEP4"},"hgnc":{"alias_symbol":["FLJ22246","FLJ22277","PP432","Yip2c"],"prev_symbol":["C8orf20"]},"alphafold":{"accession":"Q9H6H4","domains":[{"cath_id":"-","chopping":"2-81","consensus_level":"medium","plddt":76.0989,"start":2,"end":81},{"cath_id":"1.10.287","chopping":"101-153","consensus_level":"medium","plddt":83.8555,"start":101,"end":153}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q9H6H4","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q9H6H4-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q9H6H4-F1-predicted_aligned_error_v6.png","plddt_mean":64.56},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=REEP4","jax_strain_url":"https://www.jax.org/strain/search?query=REEP4"},"sequence":{"accession":"Q9H6H4","fasta_url":"https://rest.uniprot.org/uniprotkb/Q9H6H4.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q9H6H4/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q9H6H4"}},"corpus_meta":[{"pmid":"23911198","id":"PMC_23911198","title":"REEP3/4 ensure endoplasmic reticulum clearance from metaphase chromatin and proper nuclear envelope architecture.","date":"2013","source":"Developmental cell","url":"https://pubmed.ncbi.nlm.nih.gov/23911198","citation_count":113,"is_preprint":false},{"pmid":"21725060","id":"PMC_21725060","title":"Visualization and biochemical analyses of the emerging mammalian 14-3-3-phosphoproteome.","date":"2011","source":"Molecular & cellular proteomics : MCP","url":"https://pubmed.ncbi.nlm.nih.gov/21725060","citation_count":64,"is_preprint":false},{"pmid":"30995177","id":"PMC_30995177","title":"REEP3 and REEP4 determine the tubular morphology of the endoplasmic reticulum during mitosis.","date":"2019","source":"Molecular biology of the cell","url":"https://pubmed.ncbi.nlm.nih.gov/30995177","citation_count":37,"is_preprint":false},{"pmid":"36191880","id":"PMC_36191880","title":"The REEP family of proteins: Molecular targets and role in pathophysiology.","date":"2022","source":"Pharmacological research","url":"https://pubmed.ncbi.nlm.nih.gov/36191880","citation_count":25,"is_preprint":false},{"pmid":"34093663","id":"PMC_34093663","title":"Genome-Wide Detection of Copy Number Variations and Their Association With Distinct Phenotypes in the World's Sheep.","date":"2021","source":"Frontiers in genetics","url":"https://pubmed.ncbi.nlm.nih.gov/34093663","citation_count":23,"is_preprint":false},{"pmid":"29770609","id":"PMC_29770609","title":"Whole-exome sequencing for variant discovery in blepharospasm.","date":"2018","source":"Molecular genetics & genomic medicine","url":"https://pubmed.ncbi.nlm.nih.gov/29770609","citation_count":22,"is_preprint":false},{"pmid":"34874453","id":"PMC_34874453","title":"Reticulon-like REEP4 at the inner nuclear membrane promotes nuclear pore complex formation.","date":"2021","source":"The Journal of cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/34874453","citation_count":17,"is_preprint":false},{"pmid":"19123125","id":"PMC_19123125","title":"Loss of REEP4 causes paralysis of the Xenopus embryo.","date":"2009","source":"The International journal of developmental biology","url":"https://pubmed.ncbi.nlm.nih.gov/19123125","citation_count":10,"is_preprint":false},{"pmid":"35044558","id":"PMC_35044558","title":"Genetic screening in patients of Meige syndrome and blepharospasm.","date":"2022","source":"Neurological sciences : official journal of the Italian Neurological Society and of the Italian Society of Clinical Neurophysiology","url":"https://pubmed.ncbi.nlm.nih.gov/35044558","citation_count":7,"is_preprint":false},{"pmid":"37818043","id":"PMC_37818043","title":"Multiomics and bioinformatics identify differentially expressed effectors in the brain of Toxoplasma gondii infected masked palm civet.","date":"2023","source":"Frontiers in cellular and infection microbiology","url":"https://pubmed.ncbi.nlm.nih.gov/37818043","citation_count":5,"is_preprint":false},{"pmid":"38163952","id":"PMC_38163952","title":"REEPing the harvest of reticulophagy and nucleophagy.","date":"2024","source":"Autophagy","url":"https://pubmed.ncbi.nlm.nih.gov/38163952","citation_count":1,"is_preprint":false},{"pmid":"40434516","id":"PMC_40434516","title":"Molecular genetic analysis of pulmonary benign metastasizing leiomyoma and intravenous leiomyomatosis: a comparative study using whole exome sequencing.","date":"2025","source":"Discover oncology","url":"https://pubmed.ncbi.nlm.nih.gov/40434516","citation_count":1,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":7983,"output_tokens":1594,"usd":0.023929,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":8407,"output_tokens":2071,"usd":0.046905,"stage2_stop_reason":"end_turn"},"total_usd":0.070834,"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\": 2013,\n      \"finding\": \"REEP4 (and the closely related REEP3) localizes to the endoplasmic reticulum and binds microtubules via a short, positively charged amino acid sequence connecting its two hydrophobic domains; depletion of REEP3/4 from HeLa cells causes ER membranes to accumulate on metaphase chromosomes, demonstrating that REEP3/4 function redundantly to clear ER from metaphase chromatin and ensure correct mitotic progression.\",\n      \"method\": \"Biochemical screen for microtubule-membrane linkers, siRNA depletion in HeLa cells, live-cell imaging, domain mutagenesis (positively charged linker sequence)\",\n      \"journal\": \"Developmental Cell\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — biochemical screen, domain mutagenesis, siRNA KD with defined mitotic phenotype, multiple orthogonal methods in one study\",\n      \"pmids\": [\"23911198\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"Depletion of REEP3/4 in HeLa cells results in a proliferation of intranuclear membranes derived from the nuclear envelope, a defect that originates in mitosis when ER accumulates on chromosomes, establishing a causal link between REEP3/4 mitotic function and proper nuclear envelope architecture in daughter cells.\",\n      \"method\": \"siRNA depletion in HeLa cells, electron microscopy/fluorescence microscopy of nuclear envelope architecture\",\n      \"journal\": \"Developmental Cell\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — loss-of-function with defined morphological phenotype, multiple orthogonal imaging methods, single rigorous study\",\n      \"pmids\": [\"23911198\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"REEP3 and REEP4 promote ER tubulation during mitosis through their reticulon homology domains (RHDs), generating the high-curvature morphology of mitotic ER; this ER-shaping activity is mechanistically distinct from their previously described function in clearing ER from metaphase chromatin, and the REEP3/4 C-terminus mediates regulation of this activity.\",\n      \"method\": \"siRNA depletion in cultured cells, live-cell fluorescence and electron microscopy of ER morphology, domain analysis (RHD and C-terminus)\",\n      \"journal\": \"Molecular Biology of the Cell\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — loss-of-function with defined ER morphology phenotype, domain dissection, orthogonal imaging methods, independent study replicating and extending REEP3/4 function\",\n      \"pmids\": [\"30995177\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"REEP4 localizes not only to high-curvature cytoplasmic ER but is also recruited to the inner nuclear membrane by the NPC biogenesis factor ELYS; this inner-nuclear-membrane pool of REEP4 promotes nuclear pore complex (NPC) assembly, with a particular requirement during mitotic NPC biogenesis.\",\n      \"method\": \"Fluorescence microscopy (localization to inner nuclear membrane), Co-IP/interaction with ELYS, siRNA depletion with NPC assembly assay, mitotic NPC biogenesis assay\",\n      \"journal\": \"Journal of Cell Biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — reciprocal interaction with ELYS, defined subcellular localization with functional consequence, loss-of-function NPC assembly phenotype, multiple orthogonal methods in one study\",\n      \"pmids\": [\"34874453\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"REEP4 contains a phosphorylated 14-3-3-binding site in its cytoplasmic domain; 14-3-3 proteins undergo physiological interaction with ER-tethered REEP4 in a phosphorylation-dependent manner.\",\n      \"method\": \"14-3-3 affinity purification, mass spectrometry phosphoproteomics, experimental validation of binding site\",\n      \"journal\": \"Molecular & Cellular Proteomics\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 / Moderate — phosphoproteomics with experimental validation of binding site, but mechanistic consequence not defined\",\n      \"pmids\": [\"21725060\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2009,\n      \"finding\": \"Morpholino-mediated knockdown of REEP4 in Xenopus tropicalis embryos causes a kinked body axis and paralysis, with normal early expression of neural and muscle markers that subsequently downregulate by tailbud stage, indicating REEP4 is required for maintenance of both the nervous system and musculature during early vertebrate development.\",\n      \"method\": \"Antisense morpholino oligonucleotide knockdown in Xenopus tropicalis, in situ hybridization/marker gene expression analysis\",\n      \"journal\": \"International Journal of Developmental Biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Weak — clean loss-of-function with defined developmental phenotype and marker analysis, single lab/study, no molecular mechanism identified\",\n      \"pmids\": [\"19123125\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"REEP4 is an ER membrane protein with a reticulon homology domain (RHD) that uses a positively charged linker between its two hydrophobic domains to bind microtubules and, together with REEP3, clears ER from metaphase chromosomes during mitosis; its RHD drives high-curvature ER tubulation specifically during mitosis; it is additionally recruited to the inner nuclear membrane by ELYS, where it promotes nuclear pore complex assembly particularly during mitotic NPC biogenesis; and its cytoplasmic domain contains a phosphorylation-dependent 14-3-3-binding site, placing it in a signaling nexus that coordinates ER morphogenesis, nuclear envelope reformation, and cell cycle progression.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"REEP4 is an endoplasmic reticulum membrane protein that coordinates ER morphogenesis with mitotic progression and nuclear envelope organization [#0, #2]. Together with the closely related REEP3, it binds microtubules through a short positively charged sequence between its two hydrophobic domains and clears ER membranes from metaphase chromosomes; loss of REEP3/4 causes ER to accumulate on mitotic chromatin and produces aberrant intranuclear membranes in daughter cells [#0, #1]. Distinct from this clearance function, its reticulon homology domain drives the high-curvature ER tubulation characteristic of mitotic ER, with the C-terminus regulating this activity [#2]. A separate pool of REEP4 is recruited to the inner nuclear membrane by the NPC biogenesis factor ELYS, where it promotes nuclear pore complex assembly, particularly during mitosis [#3]. Its cytoplasmic domain carries a phosphorylation-dependent 14-3-3-binding site, linking REEP4 to phospho-regulatory signaling [#4]. In vertebrate development, REEP4 is required to maintain nervous-system and muscle gene expression during early embryogenesis [#5].\",\n  \"teleology\": [\n    {\n      \"year\": 2009,\n      \"claim\": \"Before any molecular role was assigned, it was unknown whether REEP4 was physiologically required in a whole organism; knockdown established an essential role in early vertebrate development.\",\n      \"evidence\": \"Antisense morpholino knockdown in Xenopus tropicalis with marker gene in situ analysis\",\n      \"pmids\": [\"19123125\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No molecular mechanism connecting REEP4 to neural/muscle maintenance\", \"Phenotype from a single study with no rescue control reported\"]\n    },\n    {\n      \"year\": 2011,\n      \"claim\": \"It was unknown how REEP4 might be regulated; phosphoproteomics identified a phosphorylation-dependent 14-3-3-binding site in its cytoplasmic domain, placing REEP4 under phospho-signaling control.\",\n      \"evidence\": \"14-3-3 affinity purification, MS phosphoproteomics, and binding-site validation\",\n      \"pmids\": [\"21725060\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Functional consequence of 14-3-3 binding undefined\", \"Kinase responsible for the phosphorylation not identified\"]\n    },\n    {\n      \"year\": 2013,\n      \"claim\": \"The cellular function of REEP4 was unresolved; a microtubule-membrane linker screen showed REEP3/4 bind microtubules via a positively charged linker and redundantly clear ER from metaphase chromatin, defining a role in mitotic ER positioning and downstream nuclear envelope integrity.\",\n      \"evidence\": \"Biochemical linker screen, siRNA depletion in HeLa cells, live imaging, EM, and domain mutagenesis\",\n      \"pmids\": [\"23911198\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Redundancy with REEP3 prevents assigning REEP4-specific contribution\", \"How the linker engages microtubules structurally not resolved\"]\n    },\n    {\n      \"year\": 2019,\n      \"claim\": \"It was unclear whether REEP3/4 only repositioned ER or also shaped it; RHD-dependent ER tubulation during mitosis was shown to be a function mechanistically distinct from chromatin clearance.\",\n      \"evidence\": \"siRNA depletion, live and electron microscopy of ER morphology, and RHD/C-terminus domain dissection\",\n      \"pmids\": [\"30995177\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Regulatory inputs governing the C-terminus-mediated control not defined\", \"Relationship to the 14-3-3 site unexplored\"]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"Whether REEP4 acted beyond the cytoplasmic ER was unknown; recruitment to the inner nuclear membrane by ELYS revealed a direct role in nuclear pore complex assembly, especially during mitotic NPC biogenesis.\",\n      \"evidence\": \"Fluorescence localization, ELYS Co-IP, and siRNA depletion with NPC assembly assays\",\n      \"pmids\": [\"34874453\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Mechanism by which REEP4 promotes NPC assembly not defined\", \"Whether ER-shaping and NPC-assembly pools are functionally separable unclear\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How REEP4's phospho-regulation, microtubule binding, ER-shaping, and ELYS-dependent NPC functions are integrated across the cell cycle remains unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No unified model linking 14-3-3 signaling to its mitotic functions\", \"REEP4-specific roles separate from REEP3 redundancy not established\", \"No structural model of the protein\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0008092\", \"supporting_discovery_ids\": [0]},\n      {\"term_id\": \"GO:0005198\", \"supporting_discovery_ids\": [2]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005783\", \"supporting_discovery_ids\": [0, 2]},\n      {\"term_id\": \"GO:0005635\", \"supporting_discovery_ids\": [3]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-1640170\", \"supporting_discovery_ids\": [0, 1, 2]},\n      {\"term_id\": \"R-HSA-1852241\", \"supporting_discovery_ids\": [3]}\n    ],\n    \"complexes\": [],\n    \"partners\": [\"REEP3\", \"ELYS\", \"YWHAZ\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":6,"faith_total":6,"faith_pct":100.0}}