{"gene":"GEMIN7","run_date":"2026-04-28T18:06:52","timeline":{"discoveries":[{"year":2002,"finding":"Gemin7 was identified as a novel component of the SMN complex; it interacts directly with SMN and Gemin6, mediates the association of Gemin6 with the SMN complex, and interacts with several Sm proteins (particularly SmE). The arginine-glycine repeats in Gemin7 are necessary for its interaction with SMN.","method":"Native purification of SMN complexes, peptide sequencing by mass spectrometry, co-immunoprecipitation, immunolocalization, and direct binding experiments","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 2 — reciprocal Co-IP, direct binding, localization, mutagenesis of RG repeats; foundational identification paper with multiple orthogonal methods","pmids":["12065586"],"is_preprint":false},{"year":2005,"finding":"Crystal structure of the Gemin6-Gemin7 heterodimer revealed that both proteins adopt canonical Sm folds despite lacking sequence similarity to Sm proteins, and they interact with each other via an Sm-protein-like interface. The Gemin6/Gemin7 complex binds to Sm proteins, suggesting a role in organizing Sm proteins for snRNA ring formation.","method":"X-ray crystallography and in vitro binding experiments","journal":"Structure","confidence":"High","confidence_rationale":"Tier 1 — crystal structure with functional binding validation","pmids":["15939020"],"is_preprint":false},{"year":2005,"finding":"Unrip is recruited to the SMN complex via a stable, direct interaction with Gemin7. This interaction is mutually exclusive with unrip's association with the unr protein complex, and RNAi-mediated reduction of unrip leads to enhanced nuclear accumulation of SMN (increased gems/Cajal bodies), demonstrating that the Gemin7-unrip interaction influences intracellular distribution of the SMN complex.","method":"Co-immunoprecipitation, RNAi knockdown, immunofluorescence microscopy","journal":"Human molecular genetics","confidence":"High","confidence_rationale":"Tier 2 — direct interaction demonstrated by Co-IP, functional consequence confirmed by RNAi with localization readout, replicated across two independent labs","pmids":["16159890","15848170"],"is_preprint":false},{"year":2005,"finding":"Unrip directly interacts with both Gemin6 and Gemin7, and unrip-containing SMN complexes are necessary and sufficient to mediate spliceosomal snRNP assembly in vitro.","method":"Co-immunoprecipitation, in vitro snRNP assembly assay","journal":"FEBS letters","confidence":"High","confidence_rationale":"Tier 2 — direct interaction plus functional reconstitution assay","pmids":["15848170"],"is_preprint":false},{"year":2006,"finding":"Gemin7 is a central building block of the SMN complex architecture together with SMN and Gemin8; the SMN complex can be reconstituted from individual components and Gemin7 is among the core components onto which peripheral components are assembled via multiple interactions.","method":"In vivo and in vitro binding assays, reconstitution of SMN complex from individual components","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1 — complex reconstitution from purified components with comprehensive interaction mapping","pmids":["17178713"],"is_preprint":false},{"year":2006,"finding":"Gemin6, Gemin7, and Unrip form a stable cytoplasmic heteromeric subunit of the SMN complex; Gemin8 directly binds SMN and mediates the interaction of SMN with the Gemin6/Gemin7 heterodimer. Loss of Gemin8 disrupts the Gemin6/Gemin7/Unrip–SMN interaction, impairing Sm protein recruitment to the snRNP assembly pathway without affecting snRNA binding.","method":"Co-immunoprecipitation with monoclonal antibodies, RNA interference, in vitro binding assays","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 2 — RNAi epistasis with defined molecular readout plus direct binding experiments, two independent papers","pmids":["16434402","17023415"],"is_preprint":false},{"year":2007,"finding":"Gemin6, Gemin7, and Unrip form a stable SMN-independent subcomplex that persists even when SMN levels are reduced. This subcomplex participates in snRNP assembly as a distinct module within the SMN complex.","method":"Sedimentation analysis, immunoprecipitation from cell extracts","journal":"The Journal of biological chemistry","confidence":"Medium","confidence_rationale":"Tier 2 — sedimentation and IP demonstrating stable subcomplex; single lab but two orthogonal biochemical methods","pmids":["17640873"],"is_preprint":false},{"year":2009,"finding":"Gemin2 directly interacts with Gemin7 (identified by mammalian two-hybrid), stabilizing the SMN-Gemin7 interaction. Gemin7 knockdown reduces snRNP assembly activity and decreases SmE in the SMN complex. Unrip (but not Gemin8) can displace Gemin7 from the SMN-Gemin2-Gemin7 ternary complex, suggesting the Gemin6-Gemin7 heterodimer acts as a surrogate for the SmD3-SmB particle and is exchanged by SmD3-SmB during snRNP formation.","method":"Mammalian two-hybrid, in vitro stability assay, RNAi knockdown of Gemin7 and Unrip, in vitro snRNP assembly assay","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1-2 — multiple orthogonal methods including two-hybrid, in vitro assembly assay, and RNAi with defined molecular readouts","pmids":["19321448"],"is_preprint":false},{"year":2005,"finding":"Gemin7 (along with SMN, Gemin2, Gemin6, and Unrip) localizes to neurite-like cytoplasmic extensions and growth cones of differentiating PC12 cells, suggesting SMN complexes containing Gemin7 participate in axonal transport of mRNPs.","method":"Immunofluorescence colocalization in differentiating PC12 cells","journal":"Experimental cell research","confidence":"Medium","confidence_rationale":"Tier 3 — localization by immunofluorescence; consistent with functional transport role but no direct functional manipulation of Gemin7","pmids":["15975577"],"is_preprint":false},{"year":2010,"finding":"Live-cell imaging of GFP-Gemin7 in neuronal cells revealed that SMN-Gemin complexes localize to two distinct subsets of neurite granules: stationary bodies and smaller dynamic (motile) bodies, and that SMN granules appear metamorphic in composition.","method":"Live-cell fluorescence imaging of GFP-tagged Gemin7 in neuronal cells","journal":"Biochemical and biophysical research communications","confidence":"Medium","confidence_rationale":"Tier 2 — direct live-cell imaging with functional localization distinction; single lab","pmids":["20188701"],"is_preprint":false},{"year":2017,"finding":"In Drosophila, the Gemin6/7/Unrip module can be recruited to the SMN complex via a Gemin8 orthologue, mirroring the human SMN complex architecture and confirming the conserved role of Gemin7 in this modular subunit.","method":"In vivo interaction assays in Drosophila (co-immunoprecipitation)","journal":"FEBS letters","confidence":"Medium","confidence_rationale":"Tier 3 — in vivo interaction in Drosophila ortholog confirming conserved module architecture; single lab","pmids":["28949413"],"is_preprint":false}],"current_model":"Gemin7 is a central structural and functional component of the SMN complex: it adopts an Sm-like fold and forms a stable heterodimer with Gemin6 (via an Sm-protein-like interface) that binds Sm proteins and acts as a surrogate SmD3-SmB particle during snRNP assembly; Gemin7 directly interacts with SMN (via its RG repeats), Gemin2, and SmE, and recruits Unrip to the complex, while Gemin8 bridges the Gemin6/Gemin7 heterodimer to SMN; the Gemin6-Gemin7-Unrip subcomplex is exchanged by SmD3-SmB (facilitated by Unrip) to complete snRNP ring formation, and this subcomplex also localizes to neuronal transport granules in axons."},"narrative":{"teleology":[{"year":2002,"claim":"Identification of GEMIN7 as a novel SMN-complex component that directly contacts SMN, GEMIN6, and Sm proteins established it as a previously unrecognized participant in the snRNP assembly machinery.","evidence":"Native SMN complex purification, mass spectrometry, reciprocal co-IP, direct binding assays, and RG-repeat mutagenesis in human cells","pmids":["12065586"],"confidence":"High","gaps":["Structural basis of the GEMIN7–SMN interaction unresolved","No functional assay for snRNP assembly performed at this stage"]},{"year":2005,"claim":"The crystal structure of the GEMIN6–GEMIN7 heterodimer revealed that both adopt Sm folds and interact through an Sm-like interface, explaining how they can bind Sm proteins and suggesting they template Sm ring organization.","evidence":"X-ray crystallography of the GEMIN6–GEMIN7 complex with in vitro Sm-protein binding validation","pmids":["15939020"],"confidence":"High","gaps":["How the heterodimer is positioned relative to the Sm ring during assembly was not resolved","No full-complex structural model available"]},{"year":2005,"claim":"Discovery that Unrip is recruited to the SMN complex through direct binding to GEMIN7 and that this interaction regulates SMN nuclear-cytoplasmic distribution linked GEMIN7 to a regulatory axis controlling SMN complex localization.","evidence":"Co-IP, RNAi knockdown of Unrip with immunofluorescence readout of gems/Cajal bodies in HeLa cells; confirmed across two independent labs","pmids":["16159890","15848170"],"confidence":"High","gaps":["Molecular basis of Unrip-mediated retention of SMN in the cytoplasm unknown","Whether Unrip regulation is relevant in motor neurons specifically not tested"]},{"year":2006,"claim":"Reconstitution of the SMN complex from individual components demonstrated that GEMIN7, together with SMN and GEMIN8, constitutes a core architectural scaffold, with GEMIN8 bridging the GEMIN6/7 heterodimer to SMN.","evidence":"In vitro complex reconstitution from purified components, RNAi epistasis, and direct binding assays","pmids":["17178713","16434402","17023415"],"confidence":"High","gaps":["Whether GEMIN8 loss completely abolishes GEMIN7 function or only reduces efficiency unclear","Stoichiometry of GEMIN7 within the native complex not determined"]},{"year":2007,"claim":"Demonstration that the GEMIN6–GEMIN7–Unrip subcomplex persists independently of SMN levels established it as a pre-formed module that is recruited en bloc to the assembly machinery.","evidence":"Sedimentation analysis and immunoprecipitation from SMN-depleted cell extracts","pmids":["17640873"],"confidence":"Medium","gaps":["Functional consequence of the free subcomplex (beyond snRNP assembly) not explored","Single-lab observation without independent replication"]},{"year":2009,"claim":"Identification of a GEMIN2–GEMIN7 direct interaction and the finding that the GEMIN6–GEMIN7 heterodimer is displaced by SmD3–SmB during ring closure revealed the mechanistic logic: GEMIN6/7 acts as a SmD3/SmB surrogate that is exchanged to complete the Sm ring.","evidence":"Mammalian two-hybrid, in vitro displacement assays, GEMIN7 RNAi with snRNP assembly and SmE incorporation readouts","pmids":["19321448"],"confidence":"High","gaps":["Kinetics and order of the exchange reaction not defined","Whether Unrip actively catalyzes the exchange or merely permits it is unresolved"]},{"year":2010,"claim":"Live-cell imaging of GFP-GEMIN7 in neurons showed SMN-containing granules partition into stationary and motile populations in neurites, extending GEMIN7's functional context beyond snRNP assembly to neuronal RNA transport.","evidence":"Live-cell fluorescence imaging of GFP-GEMIN7 in differentiated neuronal cells and PC12 cells","pmids":["20188701","15975577"],"confidence":"Medium","gaps":["No direct manipulation of GEMIN7 in neuronal transport assays","Cargo identity of motile GEMIN7-positive granules unknown"]},{"year":2017,"claim":"Conservation of the GEMIN6/7/Unrip module in Drosophila, recruited to the SMN complex via GEMIN8, confirmed that this architectural arrangement is an ancient feature of the snRNP assembly pathway.","evidence":"Co-immunoprecipitation of Drosophila orthologs in vivo","pmids":["28949413"],"confidence":"Medium","gaps":["Functional snRNP assembly assay not performed in Drosophila for GEMIN7 specifically","Whether invertebrate GEMIN7 retains the SmD3/SmB surrogate exchange mechanism untested"]},{"year":null,"claim":"How the GEMIN6–GEMIN7 heterodimer is spatially positioned within the full SMN complex during the Sm-ring closure reaction, the precise kinetics and regulation of the SmD3–SmB exchange, and the functional significance of GEMIN7 in neuronal granule transport remain unresolved.","evidence":"","pmids":[],"confidence":"Low","gaps":["No high-resolution structure of the full SMN complex including GEMIN7 in the act of Sm ring loading","No in vivo GEMIN7-specific loss-of-function studies in neurons","Role of GEMIN7 post-translational modifications (e.g., RG-repeat methylation) unexplored"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0005198","term_label":"structural molecule activity","supporting_discovery_ids":[1,4,5]},{"term_id":"GO:0060090","term_label":"molecular adaptor activity","supporting_discovery_ids":[0,2,7]}],"localization":[{"term_id":"GO:0005829","term_label":"cytosol","supporting_discovery_ids":[5,6]},{"term_id":"GO:0005634","term_label":"nucleus","supporting_discovery_ids":[2]},{"term_id":"GO:0005856","term_label":"cytoskeleton","supporting_discovery_ids":[8,9]}],"pathway":[{"term_id":"R-HSA-8953854","term_label":"Metabolism of RNA","supporting_discovery_ids":[0,1,3,7]}],"complexes":["SMN complex","Gemin6-Gemin7-Unrip subcomplex"],"partners":["SMN","GEMIN6","GEMIN8","GEMIN2","UNRIP","SNRPE"],"other_free_text":[]},"mechanistic_narrative":"GEMIN7 is a core structural component of the SMN complex that functions in the cytoplasmic assembly of spliceosomal snRNPs. Despite lacking sequence similarity to Sm proteins, GEMIN7 adopts a canonical Sm fold and forms a stable heterodimer with GEMIN6 through an Sm-protein-like interface; this heterodimer acts as a surrogate for the SmD3–SmB particle and is exchanged by SmD3–SmB during Sm ring closure, a process facilitated by Unrip [PMID:15939020, PMID:19321448]. GEMIN7 directly binds SMN via its arginine-glycine repeats, interacts with GEMIN2 and SmE, and recruits Unrip to form a stable GEMIN6–GEMIN7–Unrip submodule that is bridged to SMN by GEMIN8 [PMID:12065586, PMID:16434402, PMID:17178713]. Beyond snRNP biogenesis, the GEMIN7-containing SMN complex localizes to neuronal transport granules in axons, where it partitions into stationary and motile populations [PMID:15975577, PMID:20188701]."},"prefetch_data":{"uniprot":{"accession":"Q9H840","full_name":"Gem-associated protein 7","aliases":["SIP3"],"length_aa":131,"mass_kda":14.5,"function":"The SMN complex catalyzes the assembly of small nuclear ribonucleoproteins (snRNPs), the building blocks of the spliceosome, and thereby plays an important role in the splicing of cellular pre-mRNAs. Most spliceosomal snRNPs contain a common set of Sm proteins SNRPB, SNRPD1, SNRPD2, SNRPD3, SNRPE, SNRPF and SNRPG that assemble in a heptameric protein ring on the Sm site of the small nuclear RNA to form the core snRNP (Sm core). In the cytosol, the Sm proteins SNRPD1, SNRPD2, SNRPE, SNRPF and SNRPG are trapped in an inactive 6S pICln-Sm complex by the chaperone CLNS1A that controls the assembly of the core snRNP. To assemble core snRNPs, the SMN complex accepts the trapped 5Sm proteins from CLNS1A forming an intermediate. Binding of snRNA inside 5Sm triggers eviction of the SMN complex, thereby allowing binding of SNRPD3 and SNRPB to complete assembly of the core snRNP","subcellular_location":"Nucleus, nucleoplasm; Nucleus, gem; Cytoplasm","url":"https://www.uniprot.org/uniprotkb/Q9H840/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":true,"resolved_as":"","url":"https://depmap.org/portal/gene/GEMIN7","classification":"Common Essential","n_dependent_lines":1041,"n_total_lines":1208,"dependency_fraction":0.8617549668874173},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/GEMIN7","total_profiled":1310},"omim":[{"mim_id":"607419","title":"GEM NUCLEAR ORGANELLE-ASSOCIATED PROTEIN 7; GEMIN7","url":"https://www.omim.org/entry/607419"},{"mim_id":"607006","title":"GEM NUCLEAR ORGANELLE-ASSOCIATED PROTEIN 6; GEMIN6","url":"https://www.omim.org/entry/607006"},{"mim_id":"605986","title":"SERINE/THREONINE KINASE RECEPTOR-ASSOCIATED PROTEIN; STRAP","url":"https://www.omim.org/entry/605986"},{"mim_id":"602595","title":"GEM NUCLEAR ORGANELLE-ASSOCIATED PROTEIN 2; GEMIN2","url":"https://www.omim.org/entry/602595"},{"mim_id":"600354","title":"SURVIVAL OF MOTOR NEURON 1; SMN1","url":"https://www.omim.org/entry/600354"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Supported","locations":[{"location":"Nucleoplasm","reliability":"Supported"},{"location":"Cytosol","reliability":"Supported"}],"tissue_specificity":"Low tissue specificity","tissue_distribution":"Detected in all","driving_tissues":[],"url":"https://www.proteinatlas.org/search/GEMIN7"},"hgnc":{"alias_symbol":["FLJ13956"],"prev_symbol":[]},"alphafold":{"accession":"Q9H840","domains":[{"cath_id":"2.30.30.100","chopping":"71-130","consensus_level":"high","plddt":97.3928,"start":71,"end":130}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q9H840","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q9H840-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q9H840-F1-predicted_aligned_error_v6.png","plddt_mean":80.25},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=GEMIN7","jax_strain_url":"https://www.jax.org/strain/search?query=GEMIN7"},"sequence":{"accession":"Q9H840","fasta_url":"https://rest.uniprot.org/uniprotkb/Q9H840.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q9H840/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q9H840"}},"corpus_meta":[{"pmid":"17178713","id":"PMC_17178713","title":"A comprehensive interaction map of the human survival of motor neuron (SMN) complex.","date":"2006","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/17178713","citation_count":120,"is_preprint":false},{"pmid":"15975577","id":"PMC_15975577","title":"A role for complexes of survival of motor neurons (SMN) protein with gemins and profilin in neurite-like cytoplasmic extensions of cultured nerve cells.","date":"2005","source":"Experimental cell research","url":"https://pubmed.ncbi.nlm.nih.gov/15975577","citation_count":110,"is_preprint":false},{"pmid":"12065586","id":"PMC_12065586","title":"Identification and characterization of Gemin7, a novel component of the survival of motor neuron complex.","date":"2002","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/12065586","citation_count":92,"is_preprint":false},{"pmid":"16434402","id":"PMC_16434402","title":"Gemin8 is a novel component of the survival motor neuron complex and functions in small nuclear ribonucleoprotein assembly.","date":"2006","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/16434402","citation_count":87,"is_preprint":false},{"pmid":"16159890","id":"PMC_16159890","title":"Unrip, a factor implicated in cap-independent translation, associates with the cytosolic SMN complex and influences its intracellular localization.","date":"2005","source":"Human molecular genetics","url":"https://pubmed.ncbi.nlm.nih.gov/16159890","citation_count":70,"is_preprint":false},{"pmid":"15848170","id":"PMC_15848170","title":"Unrip is a component of SMN complexes active in snRNP assembly.","date":"2005","source":"FEBS letters","url":"https://pubmed.ncbi.nlm.nih.gov/15848170","citation_count":66,"is_preprint":false},{"pmid":"17640873","id":"PMC_17640873","title":"SMN-independent subunits of the SMN complex. Identification of a small nuclear ribonucleoprotein assembly intermediate.","date":"2007","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/17640873","citation_count":55,"is_preprint":false},{"pmid":"17023415","id":"PMC_17023415","title":"Gemin8 is required for the architecture and function of the survival motor neuron complex.","date":"2006","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/17023415","citation_count":49,"is_preprint":false},{"pmid":"15939020","id":"PMC_15939020","title":"The Gemin6-Gemin7 heterodimer from the survival of motor neurons complex has an Sm protein-like structure.","date":"2005","source":"Structure (London, England : 1993)","url":"https://pubmed.ncbi.nlm.nih.gov/15939020","citation_count":43,"is_preprint":false},{"pmid":"14633674","id":"PMC_14633674","title":"The contribution of genetic and epigenetic mechanisms to gene silencing in oligodendrogliomas.","date":"2003","source":"Cancer research","url":"https://pubmed.ncbi.nlm.nih.gov/14633674","citation_count":36,"is_preprint":false},{"pmid":"20515655","id":"PMC_20515655","title":"Analysis of SMN-neurite granules: Core Cajal body components are absent from SMN-cytoplasmic complexes.","date":"2010","source":"Biochemical and biophysical research communications","url":"https://pubmed.ncbi.nlm.nih.gov/20515655","citation_count":24,"is_preprint":false},{"pmid":"19321448","id":"PMC_19321448","title":"Role of survival motor neuron complex components in small nuclear ribonucleoprotein assembly.","date":"2009","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/19321448","citation_count":21,"is_preprint":false},{"pmid":"20188701","id":"PMC_20188701","title":"SMN and the Gemin proteins form sub-complexes that localise to both stationary and dynamic neurite granules.","date":"2010","source":"Biochemical and biophysical research communications","url":"https://pubmed.ncbi.nlm.nih.gov/20188701","citation_count":20,"is_preprint":false},{"pmid":"28949413","id":"PMC_28949413","title":"Novel interactors of the Drosophila Survival Motor Neuron (SMN) Complex suggest its full conservation.","date":"2017","source":"FEBS letters","url":"https://pubmed.ncbi.nlm.nih.gov/28949413","citation_count":17,"is_preprint":false},{"pmid":"30786668","id":"PMC_30786668","title":"Sporadic amyotrophic lateral sclerosis: is SMN-Gemins protein complex of importance for the relative resistance of oculomotor nucleus motoneurons to degeneration?","date":"2018","source":"Folia neuropathologica","url":"https://pubmed.ncbi.nlm.nih.gov/30786668","citation_count":0,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":8076,"output_tokens":2532,"usd":0.031104},"stage2":{"model":"claude-opus-4-6","input_tokens":5864,"output_tokens":2252,"usd":0.12843},"total_usd":0.159534,"stage1_batch_id":"msgbatch_01DzrsgVgYngY1hvM3DU1yF2","stage2_batch_id":"msgbatch_01KA9b7iRzKFdhoBUT7vCvSe","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2002,\n      \"finding\": \"Gemin7 was identified as a novel component of the SMN complex; it interacts directly with SMN and Gemin6, mediates the association of Gemin6 with the SMN complex, and interacts with several Sm proteins (particularly SmE). The arginine-glycine repeats in Gemin7 are necessary for its interaction with SMN.\",\n      \"method\": \"Native purification of SMN complexes, peptide sequencing by mass spectrometry, co-immunoprecipitation, immunolocalization, and direct binding experiments\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — reciprocal Co-IP, direct binding, localization, mutagenesis of RG repeats; foundational identification paper with multiple orthogonal methods\",\n      \"pmids\": [\"12065586\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2005,\n      \"finding\": \"Crystal structure of the Gemin6-Gemin7 heterodimer revealed that both proteins adopt canonical Sm folds despite lacking sequence similarity to Sm proteins, and they interact with each other via an Sm-protein-like interface. The Gemin6/Gemin7 complex binds to Sm proteins, suggesting a role in organizing Sm proteins for snRNA ring formation.\",\n      \"method\": \"X-ray crystallography and in vitro binding experiments\",\n      \"journal\": \"Structure\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 — crystal structure with functional binding validation\",\n      \"pmids\": [\"15939020\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2005,\n      \"finding\": \"Unrip is recruited to the SMN complex via a stable, direct interaction with Gemin7. This interaction is mutually exclusive with unrip's association with the unr protein complex, and RNAi-mediated reduction of unrip leads to enhanced nuclear accumulation of SMN (increased gems/Cajal bodies), demonstrating that the Gemin7-unrip interaction influences intracellular distribution of the SMN complex.\",\n      \"method\": \"Co-immunoprecipitation, RNAi knockdown, immunofluorescence microscopy\",\n      \"journal\": \"Human molecular genetics\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — direct interaction demonstrated by Co-IP, functional consequence confirmed by RNAi with localization readout, replicated across two independent labs\",\n      \"pmids\": [\"16159890\", \"15848170\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2005,\n      \"finding\": \"Unrip directly interacts with both Gemin6 and Gemin7, and unrip-containing SMN complexes are necessary and sufficient to mediate spliceosomal snRNP assembly in vitro.\",\n      \"method\": \"Co-immunoprecipitation, in vitro snRNP assembly assay\",\n      \"journal\": \"FEBS letters\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — direct interaction plus functional reconstitution assay\",\n      \"pmids\": [\"15848170\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2006,\n      \"finding\": \"Gemin7 is a central building block of the SMN complex architecture together with SMN and Gemin8; the SMN complex can be reconstituted from individual components and Gemin7 is among the core components onto which peripheral components are assembled via multiple interactions.\",\n      \"method\": \"In vivo and in vitro binding assays, reconstitution of SMN complex from individual components\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 — complex reconstitution from purified components with comprehensive interaction mapping\",\n      \"pmids\": [\"17178713\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2006,\n      \"finding\": \"Gemin6, Gemin7, and Unrip form a stable cytoplasmic heteromeric subunit of the SMN complex; Gemin8 directly binds SMN and mediates the interaction of SMN with the Gemin6/Gemin7 heterodimer. Loss of Gemin8 disrupts the Gemin6/Gemin7/Unrip–SMN interaction, impairing Sm protein recruitment to the snRNP assembly pathway without affecting snRNA binding.\",\n      \"method\": \"Co-immunoprecipitation with monoclonal antibodies, RNA interference, in vitro binding assays\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — RNAi epistasis with defined molecular readout plus direct binding experiments, two independent papers\",\n      \"pmids\": [\"16434402\", \"17023415\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2007,\n      \"finding\": \"Gemin6, Gemin7, and Unrip form a stable SMN-independent subcomplex that persists even when SMN levels are reduced. This subcomplex participates in snRNP assembly as a distinct module within the SMN complex.\",\n      \"method\": \"Sedimentation analysis, immunoprecipitation from cell extracts\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — sedimentation and IP demonstrating stable subcomplex; single lab but two orthogonal biochemical methods\",\n      \"pmids\": [\"17640873\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2009,\n      \"finding\": \"Gemin2 directly interacts with Gemin7 (identified by mammalian two-hybrid), stabilizing the SMN-Gemin7 interaction. Gemin7 knockdown reduces snRNP assembly activity and decreases SmE in the SMN complex. Unrip (but not Gemin8) can displace Gemin7 from the SMN-Gemin2-Gemin7 ternary complex, suggesting the Gemin6-Gemin7 heterodimer acts as a surrogate for the SmD3-SmB particle and is exchanged by SmD3-SmB during snRNP formation.\",\n      \"method\": \"Mammalian two-hybrid, in vitro stability assay, RNAi knockdown of Gemin7 and Unrip, in vitro snRNP assembly assay\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 — multiple orthogonal methods including two-hybrid, in vitro assembly assay, and RNAi with defined molecular readouts\",\n      \"pmids\": [\"19321448\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2005,\n      \"finding\": \"Gemin7 (along with SMN, Gemin2, Gemin6, and Unrip) localizes to neurite-like cytoplasmic extensions and growth cones of differentiating PC12 cells, suggesting SMN complexes containing Gemin7 participate in axonal transport of mRNPs.\",\n      \"method\": \"Immunofluorescence colocalization in differentiating PC12 cells\",\n      \"journal\": \"Experimental cell research\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 — localization by immunofluorescence; consistent with functional transport role but no direct functional manipulation of Gemin7\",\n      \"pmids\": [\"15975577\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"Live-cell imaging of GFP-Gemin7 in neuronal cells revealed that SMN-Gemin complexes localize to two distinct subsets of neurite granules: stationary bodies and smaller dynamic (motile) bodies, and that SMN granules appear metamorphic in composition.\",\n      \"method\": \"Live-cell fluorescence imaging of GFP-tagged Gemin7 in neuronal cells\",\n      \"journal\": \"Biochemical and biophysical research communications\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — direct live-cell imaging with functional localization distinction; single lab\",\n      \"pmids\": [\"20188701\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"In Drosophila, the Gemin6/7/Unrip module can be recruited to the SMN complex via a Gemin8 orthologue, mirroring the human SMN complex architecture and confirming the conserved role of Gemin7 in this modular subunit.\",\n      \"method\": \"In vivo interaction assays in Drosophila (co-immunoprecipitation)\",\n      \"journal\": \"FEBS letters\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 — in vivo interaction in Drosophila ortholog confirming conserved module architecture; single lab\",\n      \"pmids\": [\"28949413\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"Gemin7 is a central structural and functional component of the SMN complex: it adopts an Sm-like fold and forms a stable heterodimer with Gemin6 (via an Sm-protein-like interface) that binds Sm proteins and acts as a surrogate SmD3-SmB particle during snRNP assembly; Gemin7 directly interacts with SMN (via its RG repeats), Gemin2, and SmE, and recruits Unrip to the complex, while Gemin8 bridges the Gemin6/Gemin7 heterodimer to SMN; the Gemin6-Gemin7-Unrip subcomplex is exchanged by SmD3-SmB (facilitated by Unrip) to complete snRNP ring formation, and this subcomplex also localizes to neuronal transport granules in axons.\"\n}\n```","stage2_raw":"```json\n{\n  \"mechanistic_narrative\": \"GEMIN7 is a core structural component of the SMN complex that functions in the cytoplasmic assembly of spliceosomal snRNPs. Despite lacking sequence similarity to Sm proteins, GEMIN7 adopts a canonical Sm fold and forms a stable heterodimer with GEMIN6 through an Sm-protein-like interface; this heterodimer acts as a surrogate for the SmD3–SmB particle and is exchanged by SmD3–SmB during Sm ring closure, a process facilitated by Unrip [PMID:15939020, PMID:19321448]. GEMIN7 directly binds SMN via its arginine-glycine repeats, interacts with GEMIN2 and SmE, and recruits Unrip to form a stable GEMIN6–GEMIN7–Unrip submodule that is bridged to SMN by GEMIN8 [PMID:12065586, PMID:16434402, PMID:17178713]. Beyond snRNP biogenesis, the GEMIN7-containing SMN complex localizes to neuronal transport granules in axons, where it partitions into stationary and motile populations [PMID:15975577, PMID:20188701].\",\n  \"teleology\": [\n    {\n      \"year\": 2002,\n      \"claim\": \"Identification of GEMIN7 as a novel SMN-complex component that directly contacts SMN, GEMIN6, and Sm proteins established it as a previously unrecognized participant in the snRNP assembly machinery.\",\n      \"evidence\": \"Native SMN complex purification, mass spectrometry, reciprocal co-IP, direct binding assays, and RG-repeat mutagenesis in human cells\",\n      \"pmids\": [\"12065586\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Structural basis of the GEMIN7–SMN interaction unresolved\", \"No functional assay for snRNP assembly performed at this stage\"]\n    },\n    {\n      \"year\": 2005,\n      \"claim\": \"The crystal structure of the GEMIN6–GEMIN7 heterodimer revealed that both adopt Sm folds and interact through an Sm-like interface, explaining how they can bind Sm proteins and suggesting they template Sm ring organization.\",\n      \"evidence\": \"X-ray crystallography of the GEMIN6–GEMIN7 complex with in vitro Sm-protein binding validation\",\n      \"pmids\": [\"15939020\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"How the heterodimer is positioned relative to the Sm ring during assembly was not resolved\", \"No full-complex structural model available\"]\n    },\n    {\n      \"year\": 2005,\n      \"claim\": \"Discovery that Unrip is recruited to the SMN complex through direct binding to GEMIN7 and that this interaction regulates SMN nuclear-cytoplasmic distribution linked GEMIN7 to a regulatory axis controlling SMN complex localization.\",\n      \"evidence\": \"Co-IP, RNAi knockdown of Unrip with immunofluorescence readout of gems/Cajal bodies in HeLa cells; confirmed across two independent labs\",\n      \"pmids\": [\"16159890\", \"15848170\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Molecular basis of Unrip-mediated retention of SMN in the cytoplasm unknown\", \"Whether Unrip regulation is relevant in motor neurons specifically not tested\"]\n    },\n    {\n      \"year\": 2006,\n      \"claim\": \"Reconstitution of the SMN complex from individual components demonstrated that GEMIN7, together with SMN and GEMIN8, constitutes a core architectural scaffold, with GEMIN8 bridging the GEMIN6/7 heterodimer to SMN.\",\n      \"evidence\": \"In vitro complex reconstitution from purified components, RNAi epistasis, and direct binding assays\",\n      \"pmids\": [\"17178713\", \"16434402\", \"17023415\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Whether GEMIN8 loss completely abolishes GEMIN7 function or only reduces efficiency unclear\", \"Stoichiometry of GEMIN7 within the native complex not determined\"]\n    },\n    {\n      \"year\": 2007,\n      \"claim\": \"Demonstration that the GEMIN6–GEMIN7–Unrip subcomplex persists independently of SMN levels established it as a pre-formed module that is recruited en bloc to the assembly machinery.\",\n      \"evidence\": \"Sedimentation analysis and immunoprecipitation from SMN-depleted cell extracts\",\n      \"pmids\": [\"17640873\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Functional consequence of the free subcomplex (beyond snRNP assembly) not explored\", \"Single-lab observation without independent replication\"]\n    },\n    {\n      \"year\": 2009,\n      \"claim\": \"Identification of a GEMIN2–GEMIN7 direct interaction and the finding that the GEMIN6–GEMIN7 heterodimer is displaced by SmD3–SmB during ring closure revealed the mechanistic logic: GEMIN6/7 acts as a SmD3/SmB surrogate that is exchanged to complete the Sm ring.\",\n      \"evidence\": \"Mammalian two-hybrid, in vitro displacement assays, GEMIN7 RNAi with snRNP assembly and SmE incorporation readouts\",\n      \"pmids\": [\"19321448\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Kinetics and order of the exchange reaction not defined\", \"Whether Unrip actively catalyzes the exchange or merely permits it is unresolved\"]\n    },\n    {\n      \"year\": 2010,\n      \"claim\": \"Live-cell imaging of GFP-GEMIN7 in neurons showed SMN-containing granules partition into stationary and motile populations in neurites, extending GEMIN7's functional context beyond snRNP assembly to neuronal RNA transport.\",\n      \"evidence\": \"Live-cell fluorescence imaging of GFP-GEMIN7 in differentiated neuronal cells and PC12 cells\",\n      \"pmids\": [\"20188701\", \"15975577\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No direct manipulation of GEMIN7 in neuronal transport assays\", \"Cargo identity of motile GEMIN7-positive granules unknown\"]\n    },\n    {\n      \"year\": 2017,\n      \"claim\": \"Conservation of the GEMIN6/7/Unrip module in Drosophila, recruited to the SMN complex via GEMIN8, confirmed that this architectural arrangement is an ancient feature of the snRNP assembly pathway.\",\n      \"evidence\": \"Co-immunoprecipitation of Drosophila orthologs in vivo\",\n      \"pmids\": [\"28949413\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Functional snRNP assembly assay not performed in Drosophila for GEMIN7 specifically\", \"Whether invertebrate GEMIN7 retains the SmD3/SmB surrogate exchange mechanism untested\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How the GEMIN6–GEMIN7 heterodimer is spatially positioned within the full SMN complex during the Sm-ring closure reaction, the precise kinetics and regulation of the SmD3–SmB exchange, and the functional significance of GEMIN7 in neuronal granule transport remain unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"No high-resolution structure of the full SMN complex including GEMIN7 in the act of Sm ring loading\", \"No in vivo GEMIN7-specific loss-of-function studies in neurons\", \"Role of GEMIN7 post-translational modifications (e.g., RG-repeat methylation) unexplored\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0005198\", \"supporting_discovery_ids\": [1, 4, 5]},\n      {\"term_id\": \"GO:0060090\", \"supporting_discovery_ids\": [0, 2, 7]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005829\", \"supporting_discovery_ids\": [5, 6]},\n      {\"term_id\": \"GO:0005634\", \"supporting_discovery_ids\": [2]},\n      {\"term_id\": \"GO:0005856\", \"supporting_discovery_ids\": [8, 9]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-8953854\", \"supporting_discovery_ids\": [0, 1, 3, 7]}\n    ],\n    \"complexes\": [\n      \"SMN complex\",\n      \"Gemin6-Gemin7-Unrip subcomplex\"\n    ],\n    \"partners\": [\n      \"SMN\",\n      \"GEMIN6\",\n      \"GEMIN8\",\n      \"GEMIN2\",\n      \"UNRIP\",\n      \"SNRPE\"\n    ],\n    \"other_free_text\": []\n  }\n}\n```"}