{"gene":"GEMIN6","run_date":"2026-04-28T18:06:52","timeline":{"discoveries":[{"year":2001,"finding":"Gemin6 was identified as a novel component of the SMN complex by mass spectrometry from affinity-purified native SMN complexes. Co-immunoprecipitation and in vitro binding experiments demonstrated that Gemin6 is a bona fide component of the SMN complex, localizes to gems (nuclear Cajal body-related structures) in both cytoplasm and nucleus, and interacts with several Sm proteins of spliceosomal snRNPs.","method":"Mass spectrometry, affinity chromatography, co-immunoprecipitation, immunolocalization, in vitro binding experiments","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1-2 — multiple orthogonal methods (MS, Co-IP, in vitro binding, immunolocalization) in single foundational paper; replicated across subsequent studies","pmids":["11748230"],"is_preprint":false},{"year":2002,"finding":"Gemin6 and Gemin4 are components of a separate complex (miRNP) that contains eIF2C2 (an Argonaute family protein) and numerous microRNAs, distinct from the canonical SMN complex, indicating Gemin6 participates in multiple RNP complexes.","method":"Co-immunoprecipitation, mass spectrometry, RNA cloning","journal":"Genes & development","confidence":"Medium","confidence_rationale":"Tier 2 — Co-IP and MS in a highly cited paper, but Gemin6 participation in the miRNP was noted as part of the SMN complex context rather than specifically validated for Gemin6","pmids":["11914277"],"is_preprint":false},{"year":2002,"finding":"The SMN complex (containing Gemin6 among other Gemins) associates with snRNPs throughout their entire cytoplasmic biogenesis pathway, including newly exported snRNAs, assembled Sm cores, and pre-import complexes bound to snurportin1, suggesting multiple functions during snRNP biogenesis.","method":"Sedimentation, co-immunoprecipitation, immunolocalization","journal":"Molecular and cellular biology","confidence":"Medium","confidence_rationale":"Tier 2 — multiple biochemical methods establishing pathway position; Gemin6 implicated as part of the complex throughout","pmids":["12192051"],"is_preprint":false},{"year":2002,"finding":"Gemin7 interacts directly with Gemin6 and mediates the association of Gemin6 with the SMN complex; Gemin6 alone does not directly associate with SMN but requires Gemin7 as a bridge.","method":"Co-immunoprecipitation, in vitro binding experiments, mass spectrometry","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1-2 — direct binding experiments and Co-IP; replicated in subsequent structural and functional studies","pmids":["12065586"],"is_preprint":false},{"year":2005,"finding":"Crystal structure of the Gemin6-Gemin7 heterodimer revealed that both proteins adopt canonical Sm protein folds despite having no significant sequence similarity to Sm proteins. Gemin6 and Gemin7 heterodimerize via an interface analogous to Sm protein interactions, and the Gemin6/Gemin7 complex binds to Sm proteins, suggesting it acts as an Sm-like module to organize Sm proteins for snRNP assembly.","method":"X-ray crystallography, in vitro binding experiments","journal":"Structure (London, England : 1993)","confidence":"High","confidence_rationale":"Tier 1 — crystal structure plus functional binding experiments; provides direct mechanistic framework","pmids":["15939020"],"is_preprint":false},{"year":2005,"finding":"RNA interference knockdown of Gemin6 strongly decreases snRNP assembly activity of the SMN complex and causes disappearance of nuclear Gems, demonstrating that Gemin6 is critical for the functional activity of the SMN complex.","method":"RNA interference (RNAi), snRNP assembly assay, immunofluorescence","journal":"Human molecular genetics","confidence":"High","confidence_rationale":"Tier 2 — RNAi with defined functional readout (snRNP assembly assay) and cellular phenotype; corroborated by structural findings","pmids":["15843395"],"is_preprint":false},{"year":2005,"finding":"Unrip (unr-interacting protein) directly interacts with Gemin6 and Gemin7, and unrip-containing SMN complexes are necessary and sufficient for snRNP assembly, placing Gemin6 in the snRNP-assembly-competent sub-complex.","method":"Co-immunoprecipitation, in vitro binding, snRNP assembly assay","journal":"FEBS letters","confidence":"High","confidence_rationale":"Tier 1-2 — direct binding and functional reconstitution; replicated in subsequent studies","pmids":["15848170"],"is_preprint":false},{"year":2005,"finding":"Gemin6 co-localizes with SMN and profilin II in cytoplasmic neurite-like extensions and growth cones of differentiating PC12 cells, suggesting Gemin6-containing SMN complexes participate in axonal transport of mRNPs.","method":"Immunofluorescence co-localization, live cell imaging in differentiating PC12 cells","journal":"Experimental cell research","confidence":"Medium","confidence_rationale":"Tier 3 — localization experiment with functional inference but no direct functional readout for Gemin6 specifically","pmids":["15975577"],"is_preprint":false},{"year":2006,"finding":"Gemin8 binds directly to the Gemin6-Gemin7 heterodimer and mediates its interaction with SMN; Gemin6, Gemin7, and Unrip form a stable cytoplasmic sub-complex whose association with SMN requires Gemin8. Loss of Gemin8 prevents Gemin6/Gemin7/Unrip interaction with SMN and impairs Sm protein recruitment to the snRNP assembly pathway.","method":"Co-immunoprecipitation, RNA interference, snRNP assembly assay, monoclonal antibodies","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1-2 — multiple orthogonal methods defining Gemin6's position within the SMN complex architecture and its functional consequence","pmids":["16434402","17023415"],"is_preprint":false},{"year":2007,"finding":"Sedimentation and immunoprecipitation experiments identified a stable Gemin6-Gemin7-Unrip sub-complex that exists independently of SMN and persists when SMN is reduced. This sub-complex represents a modular unit of the SMN complex involved in snRNP assembly.","method":"Sucrose gradient sedimentation, co-immunoprecipitation, immunofluorescence","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 2 — multiple biochemical methods; clearly defines Gemin6 as part of an SMN-independent sub-complex","pmids":["17640873"],"is_preprint":false},{"year":2009,"finding":"The Gemin6-Gemin7 heterodimer functions as a surrogate for the SmD3-SmB particle in forming a snRNP assembly subcore intermediate; Unrip facilitates removal of the Gemin6-Gemin7 heterodimer from the SMN complex to allow exchange with SmD3-SmB during snRNP formation.","method":"Mammalian two-hybrid, in vitro stability assay, siRNA knockdown, in vitro snRNP assembly assay","journal":"The Journal of biological chemistry","confidence":"Medium","confidence_rationale":"Tier 2 — in vitro assembly assay combined with knockdown, but proposed exchange mechanism is from a single lab","pmids":["19321448"],"is_preprint":false},{"year":2010,"finding":"Live cell imaging of GFP-Gemin6 in neurites showed that Gemin6 localizes to two distinct subsets of bodies in neurites: stationary bodies and smaller dynamic (motile) bodies, consistent with a role in axonal transport of mRNPs.","method":"Live cell fluorescence imaging of GFP-tagged Gemin6 in neuronal cells","journal":"Biochemical and biophysical research communications","confidence":"Medium","confidence_rationale":"Tier 3 — direct localization by live imaging, but functional consequence for Gemin6 specifically not established","pmids":["20188701"],"is_preprint":false},{"year":2023,"finding":"In fission yeast (Schizosaccharomyces pombe), a minimal SMN complex containing SMN/Gemin2/Gemin6-8 is necessary and sufficient for Sm core snRNP assembly in vitro using reconstituted recombinant proteins, demonstrating that Gemin6 is an essential component of the conserved snRNP assembly chaperone machinery.","method":"Reconstitution with recombinant proteins, in vitro snRNP assembly assay, genetic approaches","journal":"iScience","confidence":"High","confidence_rationale":"Tier 1 — full in vitro reconstitution with recombinant proteins demonstrating necessity and sufficiency","pmids":["37664592"],"is_preprint":false},{"year":2025,"finding":"LGI3 interacts with GEMIN6 and inhibits its ubiquitination-mediated degradation, stabilizing GEMIN6 protein levels. Elevated GEMIN6 promotes mRNA maturation of Aurora B kinase (AURKB), thereby driving progression of TFE3-rearranged renal cell carcinoma. Drugs targeting GEMIN6 suppress TFE3-RCC cell and organoid growth.","method":"Co-immunoprecipitation, ubiquitination assay, mRNA maturation assay, pharmacological inhibition, organoid models","journal":"Oncogene","confidence":"Medium","confidence_rationale":"Tier 2 — multiple methods establishing LGI3-GEMIN6 interaction and downstream AURKB mRNA maturation, but single lab study","pmids":["40849584"],"is_preprint":false}],"current_model":"GEMIN6 is an integral component of the SMN complex that adopts a canonical Sm protein fold and heterodimerizes with GEMIN7 via an Sm-like interface; this GEMIN6-GEMIN7 heterodimer (linked to SMN via GEMIN8, and associated with Unrip) functions as an Sm protein surrogate to recruit and organize Sm proteins during ATP-dependent assembly of spliceosomal snRNPs, and is required for SMN complex activity in the cytoplasm, in nuclear gems, and in axonal neurite granules."},"narrative":{"teleology":[{"year":2001,"claim":"Establishing GEMIN6 as a bona fide SMN complex subunit resolved its identity, localization, and direct Sm protein contacts, providing the first evidence that the complex contained additional assembly factors beyond the originally known Gemins.","evidence":"Mass spectrometry of affinity-purified SMN complexes, co-IP, in vitro binding, immunolocalization in HeLa cells","pmids":["11748230"],"confidence":"High","gaps":["Direct binding partners within the SMN complex not mapped","Functional contribution of GEMIN6 to snRNP assembly not yet tested"]},{"year":2002,"claim":"Identifying GEMIN7 as the obligate direct partner of GEMIN6 and showing that GEMIN6 requires GEMIN7 for SMN complex association defined the heterodimeric architecture through which GEMIN6 is integrated into the complex.","evidence":"In vitro binding and co-IP mapping direct GEMIN6–GEMIN7 interaction","pmids":["12065586"],"confidence":"High","gaps":["Structural basis of the heterodimer unknown","Why GEMIN6 cannot bind SMN directly was unexplained"]},{"year":2005,"claim":"The crystal structure of the GEMIN6–GEMIN7 heterodimer revealed unexpected Sm-fold architecture and an Sm-like dimerization interface, fundamentally reframing GEMIN6 as an Sm protein surrogate rather than a mere scaffolding component.","evidence":"X-ray crystallography at atomic resolution plus in vitro Sm protein binding assays","pmids":["15939020"],"confidence":"High","gaps":["How the Sm-like fold functions during assembly was not directly demonstrated","No structure of the full SMN complex context"]},{"year":2005,"claim":"RNAi knockdown of GEMIN6 abolished snRNP assembly and eliminated nuclear gems, providing the first functional proof that GEMIN6 is required for SMN complex activity, not merely a structural passenger.","evidence":"siRNA knockdown in HeLa cells with snRNP assembly assay and immunofluorescence","pmids":["15843395"],"confidence":"High","gaps":["Whether the defect is due to loss of GEMIN6 per se or destabilization of the entire sub-complex was not distinguished"]},{"year":2005,"claim":"Discovery that Unrip directly binds GEMIN6/GEMIN7 and that Unrip-containing complexes are assembly-competent placed GEMIN6 within a defined functional sub-module of the SMN machinery.","evidence":"Co-IP, in vitro binding, and snRNP assembly reconstitution","pmids":["15848170"],"confidence":"High","gaps":["Role of Unrip in regulating GEMIN6 within the sub-complex was unclear"]},{"year":2006,"claim":"GEMIN8 was identified as the bridge linking the GEMIN6–GEMIN7–Unrip sub-complex to SMN, completing the hierarchical assembly map and explaining why GEMIN6 depends on intermediary factors for SMN association.","evidence":"Co-IP, RNAi of GEMIN8 with snRNP assembly readout and sub-complex disruption analysis","pmids":["16434402","17023415"],"confidence":"High","gaps":["Stoichiometry and dynamics of the GEMIN8-mediated connection not resolved"]},{"year":2007,"claim":"Demonstration that a GEMIN6–GEMIN7–Unrip sub-complex persists independently of SMN established this module as a pre-assembled unit, suggesting a stepwise pathway of SMN complex formation.","evidence":"Sucrose gradient sedimentation and co-IP under SMN-depleted conditions","pmids":["17640873"],"confidence":"High","gaps":["Whether this free sub-complex has independent activity was not tested"]},{"year":2009,"claim":"Functional studies showed GEMIN6–GEMIN7 acts as a placeholder for SmD3–SmB during assembly intermediate formation, with Unrip facilitating the exchange, providing the first mechanistic model for how the Sm-fold surrogate operates during snRNP biogenesis.","evidence":"Mammalian two-hybrid, in vitro stability and assembly assays, siRNA knockdown","pmids":["19321448"],"confidence":"Medium","gaps":["Exchange mechanism from a single laboratory","Kinetics and regulation of the exchange step not characterized","No direct structural visualization of the intermediate"]},{"year":2023,"claim":"Reconstitution of a minimal SMN complex (SMN/Gemin2/Gemin6–8) sufficient for Sm core assembly in vitro from recombinant fission yeast proteins proved that GEMIN6 is part of the evolutionarily conserved core snRNP assembly machinery.","evidence":"Full in vitro reconstitution with purified recombinant proteins and snRNP assembly assay in S. pombe system","pmids":["37664592"],"confidence":"High","gaps":["Whether mammalian GEMIN6 can be reconstituted with equal sufficiency not shown","Role of peripheral Gemins (3–5) relative to the minimal core not addressed"]},{"year":2025,"claim":"LGI3 was found to stabilize GEMIN6 by inhibiting its ubiquitin-mediated degradation, and elevated GEMIN6 promotes AURKB mRNA maturation to drive TFE3-rearranged renal cell carcinoma, linking GEMIN6 protein turnover to oncogenic RNA processing.","evidence":"Co-IP, ubiquitination assays, mRNA maturation analysis, pharmacological inhibition in organoid models","pmids":["40849584"],"confidence":"Medium","gaps":["Whether GEMIN6-dependent AURKB mRNA maturation operates through canonical snRNP assembly or a distinct mechanism is unknown","Findings from a single study","In vivo validation in animal models not reported"]},{"year":null,"claim":"How the GEMIN6–GEMIN7 surrogate exchange with SmD3–SmB is structurally coordinated within the intact SMN complex, and whether GEMIN6 contributes to RNA processing beyond canonical snRNP assembly (e.g., in miRNP function or mRNA maturation), remain unresolved.","evidence":"","pmids":[],"confidence":"Low","gaps":["No high-resolution structure of GEMIN6 within the full mammalian SMN complex","Independent confirmation of GEMIN6 in miRNP complexes lacking","Mechanism linking GEMIN6 to specific mRNA maturation events not established"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0044183","term_label":"protein folding chaperone","supporting_discovery_ids":[4,10,12]},{"term_id":"GO:0005198","term_label":"structural molecule activity","supporting_discovery_ids":[4,8,9]}],"localization":[{"term_id":"GO:0005829","term_label":"cytosol","supporting_discovery_ids":[0,2,9]},{"term_id":"GO:0005634","term_label":"nucleus","supporting_discovery_ids":[0,5]}],"pathway":[{"term_id":"R-HSA-8953854","term_label":"Metabolism of RNA","supporting_discovery_ids":[2,5,10,12]}],"complexes":["SMN complex","GEMIN6-GEMIN7-Unrip sub-complex"],"partners":["GEMIN7","GEMIN8","SMN1","STRAP","LGI3"],"other_free_text":[]},"mechanistic_narrative":"GEMIN6 is an essential component of the SMN complex that functions as a chaperone for the ATP-dependent assembly of spliceosomal snRNPs. Despite lacking sequence similarity to Sm proteins, GEMIN6 adopts a canonical Sm fold and heterodimerizes with GEMIN7 via an Sm-like interface; this heterodimer acts as a structural surrogate for the SmD3–SmB particle, organizing Sm proteins onto snRNA during snRNP core assembly and being exchanged out in an Unrip-facilitated step [PMID:15939020, PMID:19321448]. The GEMIN6–GEMIN7–Unrip module exists as a stable cytoplasmic sub-complex that is linked to SMN through GEMIN8, and RNAi depletion of GEMIN6 abolishes snRNP assembly activity and eliminates nuclear gems [PMID:15843395, PMID:16434402, PMID:17640873]. In vitro reconstitution of a minimal SMN complex (SMN/Gemin2/Gemin6–8) from fission yeast demonstrated that GEMIN6 is necessary and sufficient for Sm core assembly, confirming its conserved and indispensable role in the snRNP biogenesis machinery [PMID:37664592]."},"prefetch_data":{"uniprot":{"accession":"Q8WXD5","full_name":"Gem-associated protein 6","aliases":["SIP2"],"length_aa":167,"mass_kda":18.8,"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/Q8WXD5/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":true,"resolved_as":"","url":"https://depmap.org/portal/gene/GEMIN6","classification":"Common Essential","n_dependent_lines":1108,"n_total_lines":1208,"dependency_fraction":0.9172185430463576},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[{"gene":"SMN1","stoichiometry":10.0},{"gene":"SNRPC","stoichiometry":4.0},{"gene":"SNRPF","stoichiometry":4.0},{"gene":"SNRPA","stoichiometry":0.2},{"gene":"SNRPB","stoichiometry":0.2},{"gene":"SNRPD2","stoichiometry":0.2}],"url":"https://opencell.sf.czbiohub.org/search/GEMIN6","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":"606229","title":"ARGONAUTE RISC COMPONENT 2; AGO2","url":"https://www.omim.org/entry/606229"},{"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"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Supported","locations":[{"location":"Nucleoplasm","reliability":"Supported"},{"location":"Nuclear bodies","reliability":"Supported"}],"tissue_specificity":"Low tissue specificity","tissue_distribution":"Detected in all","driving_tissues":[],"url":"https://www.proteinatlas.org/search/GEMIN6"},"hgnc":{"alias_symbol":["FLJ23459"],"prev_symbol":[]},"alphafold":{"accession":"Q8WXD5","domains":[{"cath_id":"2.30.30.100","chopping":"2-83","consensus_level":"high","plddt":93.477,"start":2,"end":83},{"cath_id":"3.30.250","chopping":"95-164","consensus_level":"high","plddt":83.1796,"start":95,"end":164}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q8WXD5","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q8WXD5-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q8WXD5-F1-predicted_aligned_error_v6.png","plddt_mean":86.69},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=GEMIN6","jax_strain_url":"https://www.jax.org/strain/search?query=GEMIN6"},"sequence":{"accession":"Q8WXD5","fasta_url":"https://rest.uniprot.org/uniprotkb/Q8WXD5.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q8WXD5/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q8WXD5"}},"corpus_meta":[{"pmid":"11914277","id":"PMC_11914277","title":"miRNPs: a novel class of ribonucleoproteins containing numerous microRNAs.","date":"2002","source":"Genes & development","url":"https://pubmed.ncbi.nlm.nih.gov/11914277","citation_count":826,"is_preprint":false},{"pmid":"11748230","id":"PMC_11748230","title":"Purification of native survival of motor neurons complexes and identification of Gemin6 as a novel component.","date":"2001","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/11748230","citation_count":113,"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":"12192051","id":"PMC_12192051","title":"The SMN complex is associated with snRNPs throughout their cytoplasmic assembly pathway.","date":"2002","source":"Molecular and cellular biology","url":"https://pubmed.ncbi.nlm.nih.gov/12192051","citation_count":108,"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":"15843395","id":"PMC_15843395","title":"Gemins modulate the expression and activity of the SMN complex.","date":"2005","source":"Human molecular genetics","url":"https://pubmed.ncbi.nlm.nih.gov/15843395","citation_count":83,"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":"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":"37664592","id":"PMC_37664592","title":"Mechanism of assembly of snRNP cores assisted by ICln and the SMN complex in fission yeast.","date":"2023","source":"iScience","url":"https://pubmed.ncbi.nlm.nih.gov/37664592","citation_count":6,"is_preprint":false},{"pmid":"40849584","id":"PMC_40849584","title":"LGI3 promotes the progression of TFE3-rearranged renal cell carcinoma through GEMIN6/AURKB axis.","date":"2025","source":"Oncogene","url":"https://pubmed.ncbi.nlm.nih.gov/40849584","citation_count":0,"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":9293,"output_tokens":3090,"usd":0.037115},"stage2":{"model":"claude-opus-4-6","input_tokens":6471,"output_tokens":2464,"usd":0.140932},"total_usd":0.178047,"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\": 2001,\n      \"finding\": \"Gemin6 was identified as a novel component of the SMN complex by mass spectrometry from affinity-purified native SMN complexes. Co-immunoprecipitation and in vitro binding experiments demonstrated that Gemin6 is a bona fide component of the SMN complex, localizes to gems (nuclear Cajal body-related structures) in both cytoplasm and nucleus, and interacts with several Sm proteins of spliceosomal snRNPs.\",\n      \"method\": \"Mass spectrometry, affinity chromatography, co-immunoprecipitation, immunolocalization, in vitro binding experiments\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 — multiple orthogonal methods (MS, Co-IP, in vitro binding, immunolocalization) in single foundational paper; replicated across subsequent studies\",\n      \"pmids\": [\"11748230\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2002,\n      \"finding\": \"Gemin6 and Gemin4 are components of a separate complex (miRNP) that contains eIF2C2 (an Argonaute family protein) and numerous microRNAs, distinct from the canonical SMN complex, indicating Gemin6 participates in multiple RNP complexes.\",\n      \"method\": \"Co-immunoprecipitation, mass spectrometry, RNA cloning\",\n      \"journal\": \"Genes & development\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — Co-IP and MS in a highly cited paper, but Gemin6 participation in the miRNP was noted as part of the SMN complex context rather than specifically validated for Gemin6\",\n      \"pmids\": [\"11914277\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2002,\n      \"finding\": \"The SMN complex (containing Gemin6 among other Gemins) associates with snRNPs throughout their entire cytoplasmic biogenesis pathway, including newly exported snRNAs, assembled Sm cores, and pre-import complexes bound to snurportin1, suggesting multiple functions during snRNP biogenesis.\",\n      \"method\": \"Sedimentation, co-immunoprecipitation, immunolocalization\",\n      \"journal\": \"Molecular and cellular biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — multiple biochemical methods establishing pathway position; Gemin6 implicated as part of the complex throughout\",\n      \"pmids\": [\"12192051\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2002,\n      \"finding\": \"Gemin7 interacts directly with Gemin6 and mediates the association of Gemin6 with the SMN complex; Gemin6 alone does not directly associate with SMN but requires Gemin7 as a bridge.\",\n      \"method\": \"Co-immunoprecipitation, in vitro binding experiments, mass spectrometry\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 — direct binding experiments and Co-IP; replicated in subsequent structural and functional studies\",\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 protein folds despite having no significant sequence similarity to Sm proteins. Gemin6 and Gemin7 heterodimerize via an interface analogous to Sm protein interactions, and the Gemin6/Gemin7 complex binds to Sm proteins, suggesting it acts as an Sm-like module to organize Sm proteins for snRNP assembly.\",\n      \"method\": \"X-ray crystallography, in vitro binding experiments\",\n      \"journal\": \"Structure (London, England : 1993)\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 — crystal structure plus functional binding experiments; provides direct mechanistic framework\",\n      \"pmids\": [\"15939020\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2005,\n      \"finding\": \"RNA interference knockdown of Gemin6 strongly decreases snRNP assembly activity of the SMN complex and causes disappearance of nuclear Gems, demonstrating that Gemin6 is critical for the functional activity of the SMN complex.\",\n      \"method\": \"RNA interference (RNAi), snRNP assembly assay, immunofluorescence\",\n      \"journal\": \"Human molecular genetics\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — RNAi with defined functional readout (snRNP assembly assay) and cellular phenotype; corroborated by structural findings\",\n      \"pmids\": [\"15843395\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2005,\n      \"finding\": \"Unrip (unr-interacting protein) directly interacts with Gemin6 and Gemin7, and unrip-containing SMN complexes are necessary and sufficient for snRNP assembly, placing Gemin6 in the snRNP-assembly-competent sub-complex.\",\n      \"method\": \"Co-immunoprecipitation, in vitro binding, snRNP assembly assay\",\n      \"journal\": \"FEBS letters\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 — direct binding and functional reconstitution; replicated in subsequent studies\",\n      \"pmids\": [\"15848170\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2005,\n      \"finding\": \"Gemin6 co-localizes with SMN and profilin II in cytoplasmic neurite-like extensions and growth cones of differentiating PC12 cells, suggesting Gemin6-containing SMN complexes participate in axonal transport of mRNPs.\",\n      \"method\": \"Immunofluorescence co-localization, live cell imaging in differentiating PC12 cells\",\n      \"journal\": \"Experimental cell research\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 — localization experiment with functional inference but no direct functional readout for Gemin6 specifically\",\n      \"pmids\": [\"15975577\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2006,\n      \"finding\": \"Gemin8 binds directly to the Gemin6-Gemin7 heterodimer and mediates its interaction with SMN; Gemin6, Gemin7, and Unrip form a stable cytoplasmic sub-complex whose association with SMN requires Gemin8. Loss of Gemin8 prevents Gemin6/Gemin7/Unrip interaction with SMN and impairs Sm protein recruitment to the snRNP assembly pathway.\",\n      \"method\": \"Co-immunoprecipitation, RNA interference, snRNP assembly assay, monoclonal antibodies\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1-2 — multiple orthogonal methods defining Gemin6's position within the SMN complex architecture and its functional consequence\",\n      \"pmids\": [\"16434402\", \"17023415\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2007,\n      \"finding\": \"Sedimentation and immunoprecipitation experiments identified a stable Gemin6-Gemin7-Unrip sub-complex that exists independently of SMN and persists when SMN is reduced. This sub-complex represents a modular unit of the SMN complex involved in snRNP assembly.\",\n      \"method\": \"Sucrose gradient sedimentation, co-immunoprecipitation, immunofluorescence\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — multiple biochemical methods; clearly defines Gemin6 as part of an SMN-independent sub-complex\",\n      \"pmids\": [\"17640873\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2009,\n      \"finding\": \"The Gemin6-Gemin7 heterodimer functions as a surrogate for the SmD3-SmB particle in forming a snRNP assembly subcore intermediate; Unrip facilitates removal of the Gemin6-Gemin7 heterodimer from the SMN complex to allow exchange with SmD3-SmB during snRNP formation.\",\n      \"method\": \"Mammalian two-hybrid, in vitro stability assay, siRNA knockdown, in vitro snRNP assembly assay\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — in vitro assembly assay combined with knockdown, but proposed exchange mechanism is from a single lab\",\n      \"pmids\": [\"19321448\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"Live cell imaging of GFP-Gemin6 in neurites showed that Gemin6 localizes to two distinct subsets of bodies in neurites: stationary bodies and smaller dynamic (motile) bodies, consistent with a role in axonal transport of mRNPs.\",\n      \"method\": \"Live cell fluorescence imaging of GFP-tagged Gemin6 in neuronal cells\",\n      \"journal\": \"Biochemical and biophysical research communications\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 — direct localization by live imaging, but functional consequence for Gemin6 specifically not established\",\n      \"pmids\": [\"20188701\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"In fission yeast (Schizosaccharomyces pombe), a minimal SMN complex containing SMN/Gemin2/Gemin6-8 is necessary and sufficient for Sm core snRNP assembly in vitro using reconstituted recombinant proteins, demonstrating that Gemin6 is an essential component of the conserved snRNP assembly chaperone machinery.\",\n      \"method\": \"Reconstitution with recombinant proteins, in vitro snRNP assembly assay, genetic approaches\",\n      \"journal\": \"iScience\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 — full in vitro reconstitution with recombinant proteins demonstrating necessity and sufficiency\",\n      \"pmids\": [\"37664592\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"LGI3 interacts with GEMIN6 and inhibits its ubiquitination-mediated degradation, stabilizing GEMIN6 protein levels. Elevated GEMIN6 promotes mRNA maturation of Aurora B kinase (AURKB), thereby driving progression of TFE3-rearranged renal cell carcinoma. Drugs targeting GEMIN6 suppress TFE3-RCC cell and organoid growth.\",\n      \"method\": \"Co-immunoprecipitation, ubiquitination assay, mRNA maturation assay, pharmacological inhibition, organoid models\",\n      \"journal\": \"Oncogene\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — multiple methods establishing LGI3-GEMIN6 interaction and downstream AURKB mRNA maturation, but single lab study\",\n      \"pmids\": [\"40849584\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"GEMIN6 is an integral component of the SMN complex that adopts a canonical Sm protein fold and heterodimerizes with GEMIN7 via an Sm-like interface; this GEMIN6-GEMIN7 heterodimer (linked to SMN via GEMIN8, and associated with Unrip) functions as an Sm protein surrogate to recruit and organize Sm proteins during ATP-dependent assembly of spliceosomal snRNPs, and is required for SMN complex activity in the cytoplasm, in nuclear gems, and in axonal neurite granules.\"\n}\n```","stage2_raw":"```json\n{\n  \"mechanistic_narrative\": \"GEMIN6 is an essential component of the SMN complex that functions as a chaperone for the ATP-dependent assembly of spliceosomal snRNPs. Despite lacking sequence similarity to Sm proteins, GEMIN6 adopts a canonical Sm fold and heterodimerizes with GEMIN7 via an Sm-like interface; this heterodimer acts as a structural surrogate for the SmD3–SmB particle, organizing Sm proteins onto snRNA during snRNP core assembly and being exchanged out in an Unrip-facilitated step [PMID:15939020, PMID:19321448]. The GEMIN6–GEMIN7–Unrip module exists as a stable cytoplasmic sub-complex that is linked to SMN through GEMIN8, and RNAi depletion of GEMIN6 abolishes snRNP assembly activity and eliminates nuclear gems [PMID:15843395, PMID:16434402, PMID:17640873]. In vitro reconstitution of a minimal SMN complex (SMN/Gemin2/Gemin6–8) from fission yeast demonstrated that GEMIN6 is necessary and sufficient for Sm core assembly, confirming its conserved and indispensable role in the snRNP biogenesis machinery [PMID:37664592].\",\n  \"teleology\": [\n    {\n      \"year\": 2001,\n      \"claim\": \"Establishing GEMIN6 as a bona fide SMN complex subunit resolved its identity, localization, and direct Sm protein contacts, providing the first evidence that the complex contained additional assembly factors beyond the originally known Gemins.\",\n      \"evidence\": \"Mass spectrometry of affinity-purified SMN complexes, co-IP, in vitro binding, immunolocalization in HeLa cells\",\n      \"pmids\": [\"11748230\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Direct binding partners within the SMN complex not mapped\", \"Functional contribution of GEMIN6 to snRNP assembly not yet tested\"]\n    },\n    {\n      \"year\": 2002,\n      \"claim\": \"Identifying GEMIN7 as the obligate direct partner of GEMIN6 and showing that GEMIN6 requires GEMIN7 for SMN complex association defined the heterodimeric architecture through which GEMIN6 is integrated into the complex.\",\n      \"evidence\": \"In vitro binding and co-IP mapping direct GEMIN6–GEMIN7 interaction\",\n      \"pmids\": [\"12065586\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Structural basis of the heterodimer unknown\", \"Why GEMIN6 cannot bind SMN directly was unexplained\"]\n    },\n    {\n      \"year\": 2005,\n      \"claim\": \"The crystal structure of the GEMIN6–GEMIN7 heterodimer revealed unexpected Sm-fold architecture and an Sm-like dimerization interface, fundamentally reframing GEMIN6 as an Sm protein surrogate rather than a mere scaffolding component.\",\n      \"evidence\": \"X-ray crystallography at atomic resolution plus in vitro Sm protein binding assays\",\n      \"pmids\": [\"15939020\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"How the Sm-like fold functions during assembly was not directly demonstrated\", \"No structure of the full SMN complex context\"]\n    },\n    {\n      \"year\": 2005,\n      \"claim\": \"RNAi knockdown of GEMIN6 abolished snRNP assembly and eliminated nuclear gems, providing the first functional proof that GEMIN6 is required for SMN complex activity, not merely a structural passenger.\",\n      \"evidence\": \"siRNA knockdown in HeLa cells with snRNP assembly assay and immunofluorescence\",\n      \"pmids\": [\"15843395\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Whether the defect is due to loss of GEMIN6 per se or destabilization of the entire sub-complex was not distinguished\"]\n    },\n    {\n      \"year\": 2005,\n      \"claim\": \"Discovery that Unrip directly binds GEMIN6/GEMIN7 and that Unrip-containing complexes are assembly-competent placed GEMIN6 within a defined functional sub-module of the SMN machinery.\",\n      \"evidence\": \"Co-IP, in vitro binding, and snRNP assembly reconstitution\",\n      \"pmids\": [\"15848170\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Role of Unrip in regulating GEMIN6 within the sub-complex was unclear\"]\n    },\n    {\n      \"year\": 2006,\n      \"claim\": \"GEMIN8 was identified as the bridge linking the GEMIN6–GEMIN7–Unrip sub-complex to SMN, completing the hierarchical assembly map and explaining why GEMIN6 depends on intermediary factors for SMN association.\",\n      \"evidence\": \"Co-IP, RNAi of GEMIN8 with snRNP assembly readout and sub-complex disruption analysis\",\n      \"pmids\": [\"16434402\", \"17023415\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Stoichiometry and dynamics of the GEMIN8-mediated connection not resolved\"]\n    },\n    {\n      \"year\": 2007,\n      \"claim\": \"Demonstration that a GEMIN6–GEMIN7–Unrip sub-complex persists independently of SMN established this module as a pre-assembled unit, suggesting a stepwise pathway of SMN complex formation.\",\n      \"evidence\": \"Sucrose gradient sedimentation and co-IP under SMN-depleted conditions\",\n      \"pmids\": [\"17640873\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Whether this free sub-complex has independent activity was not tested\"]\n    },\n    {\n      \"year\": 2009,\n      \"claim\": \"Functional studies showed GEMIN6–GEMIN7 acts as a placeholder for SmD3–SmB during assembly intermediate formation, with Unrip facilitating the exchange, providing the first mechanistic model for how the Sm-fold surrogate operates during snRNP biogenesis.\",\n      \"evidence\": \"Mammalian two-hybrid, in vitro stability and assembly assays, siRNA knockdown\",\n      \"pmids\": [\"19321448\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Exchange mechanism from a single laboratory\", \"Kinetics and regulation of the exchange step not characterized\", \"No direct structural visualization of the intermediate\"]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Reconstitution of a minimal SMN complex (SMN/Gemin2/Gemin6–8) sufficient for Sm core assembly in vitro from recombinant fission yeast proteins proved that GEMIN6 is part of the evolutionarily conserved core snRNP assembly machinery.\",\n      \"evidence\": \"Full in vitro reconstitution with purified recombinant proteins and snRNP assembly assay in S. pombe system\",\n      \"pmids\": [\"37664592\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Whether mammalian GEMIN6 can be reconstituted with equal sufficiency not shown\", \"Role of peripheral Gemins (3–5) relative to the minimal core not addressed\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"LGI3 was found to stabilize GEMIN6 by inhibiting its ubiquitin-mediated degradation, and elevated GEMIN6 promotes AURKB mRNA maturation to drive TFE3-rearranged renal cell carcinoma, linking GEMIN6 protein turnover to oncogenic RNA processing.\",\n      \"evidence\": \"Co-IP, ubiquitination assays, mRNA maturation analysis, pharmacological inhibition in organoid models\",\n      \"pmids\": [\"40849584\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Whether GEMIN6-dependent AURKB mRNA maturation operates through canonical snRNP assembly or a distinct mechanism is unknown\", \"Findings from a single study\", \"In vivo validation in animal models not reported\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How the GEMIN6–GEMIN7 surrogate exchange with SmD3–SmB is structurally coordinated within the intact SMN complex, and whether GEMIN6 contributes to RNA processing beyond canonical snRNP assembly (e.g., in miRNP function or mRNA maturation), remain unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"No high-resolution structure of GEMIN6 within the full mammalian SMN complex\", \"Independent confirmation of GEMIN6 in miRNP complexes lacking\", \"Mechanism linking GEMIN6 to specific mRNA maturation events not established\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0044183\", \"supporting_discovery_ids\": [4, 10, 12]},\n      {\"term_id\": \"GO:0005198\", \"supporting_discovery_ids\": [4, 8, 9]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005829\", \"supporting_discovery_ids\": [0, 2, 9]},\n      {\"term_id\": \"GO:0005634\", \"supporting_discovery_ids\": [0, 5]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-8953854\", \"supporting_discovery_ids\": [2, 5, 10, 12]}\n    ],\n    \"complexes\": [\n      \"SMN complex\",\n      \"GEMIN6-GEMIN7-Unrip sub-complex\"\n    ],\n    \"partners\": [\n      \"GEMIN7\",\n      \"GEMIN8\",\n      \"SMN1\",\n      \"STRAP\",\n      \"LGI3\"\n    ],\n    \"other_free_text\": []\n  }\n}\n```"}