{"gene":"SH3GL3","run_date":"2026-06-10T07:46:31","timeline":{"discoveries":[{"year":1997,"finding":"SH3GL3 (SH3p13) binds to both synaptojanin and dynamin I via its SH3 domain (closely related to the Grb2 SH3 domain), and pools of synaptojanin and dynamin I were co-precipitated from brain extracts with anti-SH3p4/8/13 antibodies; the proteins are concentrated in nerve terminals, implicating SH3GL3 in synaptic vesicle recycling.","method":"Yeast two-hybrid screen (rat brain library), co-immunoprecipitation from brain extracts, immunolocalization","journal":"Proceedings of the National Academy of Sciences of the United States of America","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal Co-IP from native brain tissue plus yeast two-hybrid identification, replicated across three family members and confirmed biochemically","pmids":["9238017"],"is_preprint":false},{"year":1998,"finding":"SH3GL3 selectively interacts with the Huntingtin exon 1 protein (HDex1p) bearing a pathological-length polyglutamine repeat; the C-terminal SH3 domain of SH3GL3 and the proline-rich region of HDex1p are essential for this interaction. SH3GL3 promotes the formation of insoluble polyglutamine-containing aggregates in vivo, and co-immunoprecipitation confirmed association with full-length huntingtin from HD human brain extract.","method":"Co-immunoprecipitation (COS cell transfection and HD human brain extract), immunofluorescence co-localization, domain-deletion mutagenesis, in vivo aggregation assay","journal":"Molecular cell","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal Co-IP in both transfected cells and human brain extract, supported by mutagenesis defining essential domains and co-localization, multiple orthogonal methods in one study","pmids":["9809064"],"is_preprint":false},{"year":2009,"finding":"The BAR domain of SH3GL3 (SH3P13) interacts with DYDC1 (identified by yeast two-hybrid from a human testis library); SH3GL3 assists in regulating clathrin-coated vesicle traffic crucial for acrosome biogenesis during spermatogenesis.","method":"Yeast two-hybrid screen (human testis library using BAR domain as bait), RNA interference knockdown, germ cell transplantation","journal":"European journal of cell biology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — yeast two-hybrid plus functional RNAi knockdown demonstrating acrosome biogenesis defect, but interaction not confirmed by orthogonal biochemical method in this abstract","pmids":["19545932"],"is_preprint":false},{"year":2012,"finding":"Knockdown of SH3GL3 inhibits glioma cell invasion in vitro, establishing a functional role for SH3GL3 in glioma cell invasive behavior.","method":"shRNA knockdown, in vitro invasion assay","journal":"Neuropathology and applied neurobiology","confidence":"Medium","confidence_rationale":"Tier 3 / Moderate — clean KD with defined cellular phenotype (invasion assay), confirmed alongside two other candidate genes but limited mechanistic depth","pmids":["21722156"],"is_preprint":false},{"year":2016,"finding":"SH3GL3 promotes myeloma cell migration/invasion, stemness, and chemo-resistance; overexpression increases p-FAK and p-PI3K levels, and pharmacological inhibition of FAK or PI3K attenuates SH3GL3-mediated migration/invasion, placing SH3GL3 upstream of the FAK/PI3K signaling pathway in myeloma cells.","method":"shRNA knockdown, cDNA overexpression, FAK inhibitor and PI3K inhibitor (LY294002) treatment, migration/invasion assay, Western blot for p-FAK/p-PI3K","journal":"Oncotarget","confidence":"Medium","confidence_rationale":"Tier 3 / Moderate — gain- and loss-of-function with pathway inhibitor rescue, single lab, two orthogonal approaches (OE + KD) plus pharmacological epistasis","pmids":["27683032"],"is_preprint":false},{"year":2020,"finding":"SH3GL3 inhibits lung cancer cell proliferation, migration, and stem cell self-renewal in an SH3-domain-dependent manner, and upregulates p21 at the transcriptional level; loss of the SH3 domain abolishes these tumor-suppressive effects.","method":"Overexpression with SH3-domain deletion mutants, proliferation/migration assays, cell cycle analysis, apoptosis assay, qRT-PCR for p21","journal":"Biochemical and biophysical research communications","confidence":"Medium","confidence_rationale":"Tier 3 / Moderate — domain-deletion mutagenesis defining SH3 domain requirement plus multiple functional readouts, single lab","pmids":["33168185"],"is_preprint":false},{"year":2021,"finding":"SH3GL3 physically interacts with STAT3 and inhibits STAT3 nuclear localization in glioblastoma cells; overexpression of constitutively active STAT3 (STAT3-C) rescues the growth, migration, and self-renewal defects caused by SH3GL3 overexpression, placing SH3GL3 as a negative regulator upstream of STAT3 nuclear translocation.","method":"Co-immunoprecipitation (SH3GL3–STAT3 interaction), ectopic overexpression, constitutively active STAT3 rescue experiment, nuclear localization assay, proliferation/migration/self-renewal assays","journal":"Biochemical and biophysical research communications","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — Co-IP plus genetic epistasis rescue with STAT3-C, single lab, two orthogonal methods","pmids":["33524871"],"is_preprint":false},{"year":2023,"finding":"The lncRNA MIR210HG recruits DNMT1 to the SH3GL3 promoter region, leading to methylation-mediated transcriptional repression of SH3GL3 in lung cancer cells; knockdown of MIR210HG or overexpression of SH3GL3 suppresses lung cancer cell proliferation, migration, and invasion.","method":"Chromatin immunoprecipitation (DNMT1 binding to SH3GL3 promoter), RNA immunoprecipitation (MIR210HG–DNMT1 interaction), methylation-specific PCR, shRNA knockdown, overexpression, functional assays","journal":"The Kaohsiung journal of medical sciences","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — ChIP and RIP defining epigenetic mechanism at SH3GL3 promoter, single lab, two orthogonal molecular methods","pmids":["37916731"],"is_preprint":false}],"current_model":"SH3GL3 is a BAR- and SH3-domain-containing endophilin-family protein that, via its SH3 domain, binds synaptojanin and dynamin I at nerve terminals to facilitate synaptic vesicle recycling, interacts with the proline-rich region of polyglutamine-expanded huntingtin to promote aggregate formation, and binds DYDC1 through its BAR domain to regulate acrosome biogenesis; in cancer contexts SH3GL3 acts as a tumor suppressor by inhibiting STAT3 nuclear translocation, transcriptionally upregulating p21, and suppressing FAK/PI3K signaling, while its own transcription is silenced by DNMT1 recruited by the lncRNA MIR210HG."},"narrative":{"mechanistic_narrative":"SH3GL3 is an SH3- and BAR-domain endophilin-family protein that operates in membrane-trafficking at nerve terminals and acts as a context-dependent regulator of cell growth and invasion in cancer [PMID:9238017, PMID:33524871]. At the synapse, its SH3 domain binds synaptojanin and dynamin I, with which it co-precipitates from brain extracts and co-concentrates at nerve terminals, implicating it in synaptic vesicle recycling [PMID:9238017]. The same SH3 domain selectively engages the proline-rich region of polyglutamine-expanded huntingtin exon 1, an interaction confirmed in transfected cells and HD brain extract, through which SH3GL3 promotes the formation of insoluble polyglutamine aggregates [PMID:9809064]. Its BAR domain mediates a distinct interaction with DYDC1 that supports clathrin-coated vesicle traffic during acrosome biogenesis in spermatogenesis [PMID:19545932]. In tumor contexts SH3GL3 has opposing reported roles: in glioblastoma and lung cancer it acts as a tumor suppressor, physically binding STAT3 to block its nuclear translocation and transcriptionally upregulating p21 in an SH3-domain-dependent manner, thereby restraining proliferation, migration, and stem-cell self-renewal [PMID:33168185, PMID:33524871], and its own promoter is silenced by DNMT1 recruited via the lncRNA MIR210HG [PMID:37916731]; conversely, in myeloma and glioma it promotes invasion, with overexpression activating FAK/PI3K signaling [PMID:21722156, PMID:27683032].","teleology":[{"year":1997,"claim":"Established SH3GL3's first molecular partners and a synaptic function by showing its SH3 domain captures the vesicle-trafficking machinery.","evidence":"Yeast two-hybrid from rat brain library plus reciprocal Co-IP from brain extracts and immunolocalization at nerve terminals","pmids":["9238017"],"confidence":"High","gaps":["Direct demonstration that SH3GL3 loss impairs vesicle recycling not shown","Functional contribution relative to other endophilin family members not resolved"]},{"year":1998,"claim":"Linked SH3GL3 to Huntington disease pathology by showing it binds expanded huntingtin and drives aggregate formation, defining the essential interacting domains.","evidence":"Co-IP in transfected COS cells and HD human brain extract, domain-deletion mutagenesis, and in vivo aggregation assay","pmids":["9809064"],"confidence":"High","gaps":["Whether SH3GL3 modifies HD pathology in vivo not established","Mechanism by which the interaction nucleates insoluble aggregates not defined"]},{"year":2009,"claim":"Revealed a BAR-domain-mediated function distinct from SH3-domain partnerships, connecting SH3GL3 to acrosome biogenesis via DYDC1.","evidence":"Yeast two-hybrid (BAR domain bait, testis library), RNAi knockdown, and germ cell transplantation","pmids":["19545932"],"confidence":"Medium","gaps":["BAR-domain–DYDC1 interaction not confirmed by an orthogonal biochemical method","Molecular link between DYDC1 binding and clathrin-coated vesicle traffic unresolved"]},{"year":2012,"claim":"Extended SH3GL3 function into cancer by showing it is required for glioma cell invasion.","evidence":"shRNA knockdown with in vitro invasion assay","pmids":["21722156"],"confidence":"Medium","gaps":["No molecular mechanism for the invasion phenotype","Studied as one of several candidates with limited depth"]},{"year":2016,"claim":"Placed SH3GL3 upstream of FAK/PI3K signaling as a pro-invasive, pro-stemness factor in myeloma, contrasting with later tumor-suppressor findings.","evidence":"Gain- and loss-of-function plus FAK/PI3K inhibitor epistasis with migration/invasion assays and Western blot for p-FAK/p-PI3K","pmids":["27683032"],"confidence":"Medium","gaps":["Whether SH3GL3 directly activates FAK/PI3K or acts indirectly unknown","Tissue context driving oncogenic vs tumor-suppressive behavior unexplained"]},{"year":2020,"claim":"Defined SH3GL3 as a tumor suppressor in lung cancer that requires its SH3 domain and transcriptionally upregulates p21.","evidence":"SH3-domain deletion mutants with proliferation/migration, cell cycle, apoptosis assays and qRT-PCR for p21","pmids":["33168185"],"confidence":"Medium","gaps":["Direct mechanism connecting the SH3 domain to p21 transcription not established","Single-lab evidence without in vivo validation"]},{"year":2021,"claim":"Identified a mechanism for tumor suppression: SH3GL3 binds STAT3 and blocks its nuclear translocation in glioblastoma.","evidence":"Co-IP of SH3GL3–STAT3, nuclear localization assay, and constitutively active STAT3-C rescue of growth/migration/self-renewal","pmids":["33524871"],"confidence":"Medium","gaps":["Domain mediating STAT3 binding not mapped","How cytoplasmic sequestration of STAT3 is achieved mechanistically unclear"]},{"year":2023,"claim":"Explained how SH3GL3 is silenced in tumors, showing lncRNA MIR210HG recruits DNMT1 to methylate the SH3GL3 promoter.","evidence":"ChIP for DNMT1 at the SH3GL3 promoter, RIP for MIR210HG–DNMT1, methylation-specific PCR, and knockdown/overexpression functional assays","pmids":["37916731"],"confidence":"Medium","gaps":["Generality of this silencing axis across tumor types not established","Whether promoter methylation is the dominant in vivo regulator unknown"]},{"year":null,"claim":"It remains unresolved what determines whether SH3GL3 acts as a tumor suppressor or a pro-invasive factor, and how its synaptic/trafficking functions relate to its signaling roles in cancer.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No structural model integrating BAR- and SH3-domain functions","Context dependence of oncogenic vs tumor-suppressive behavior unexplained","Physiological relevance of synaptic functions in non-neuronal disease contexts unknown"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0008092","term_label":"cytoskeletal protein binding","supporting_discovery_ids":[0,1]},{"term_id":"GO:0098772","term_label":"molecular function regulator activity","supporting_discovery_ids":[6]}],"localization":[{"term_id":"GO:0005886","term_label":"plasma membrane","supporting_discovery_ids":[0]}],"pathway":[{"term_id":"R-HSA-5653656","term_label":"Vesicle-mediated transport","supporting_discovery_ids":[0,2]},{"term_id":"R-HSA-162582","term_label":"Signal Transduction","supporting_discovery_ids":[4,6]}],"complexes":[],"partners":["SYNJ1","DNM1","HTT","DYDC1","STAT3"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q99963","full_name":"Endophilin-A3","aliases":["EEN-B2","Endophilin-3","SH3 domain protein 2C","SH3 domain-containing GRB2-like protein 3"],"length_aa":347,"mass_kda":39.3,"function":"Implicated in endocytosis. May recruit other proteins to membranes with high curvature (By similarity)","subcellular_location":"Cytoplasm; Early endosome membrane","url":"https://www.uniprot.org/uniprotkb/Q99963/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/SH3GL3","classification":"Not Classified","n_dependent_lines":4,"n_total_lines":1208,"dependency_fraction":0.0033112582781456954},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[{"gene":"SH3GL1","stoichiometry":0.2}],"url":"https://opencell.sf.czbiohub.org/search/SH3GL3","total_profiled":1310},"omim":[{"mim_id":"615154","title":"DPY30 DOMAIN-CONTAINING PROTEIN 1; DYDC1","url":"https://www.omim.org/entry/615154"},{"mim_id":"613004","title":"HUNTINGTIN; HTT","url":"https://www.omim.org/entry/613004"},{"mim_id":"611540","title":"SH3-DOMAIN GRB2-LIKE (ENDOPHILIN)-INTERACTING PROTEIN 1; SGIP1","url":"https://www.omim.org/entry/611540"},{"mim_id":"604465","title":"SH3 DOMAIN, GRB2-LIKE, 2; SH3GL2","url":"https://www.omim.org/entry/604465"},{"mim_id":"603362","title":"SH3 DOMAIN, GRB2-LIKE, 3; SH3GL3","url":"https://www.omim.org/entry/603362"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Approved","locations":[{"location":"Mitochondria","reliability":"Approved"}],"tissue_specificity":"Group enriched","tissue_distribution":"Detected in some","driving_tissues":[{"tissue":"brain","ntpm":56.9},{"tissue":"testis","ntpm":24.8}],"url":"https://www.proteinatlas.org/search/SH3GL3"},"hgnc":{"alias_symbol":["SH3D2C","SH3P13","CNSA3","EEN-B2","HsT19371"],"prev_symbol":[]},"alphafold":{"accession":"Q99963","domains":[{"cath_id":"1.20.1270.60","chopping":"9-75_84-250","consensus_level":"high","plddt":94.9541,"start":9,"end":250},{"cath_id":"2.30.30.40","chopping":"290-344","consensus_level":"high","plddt":91.6607,"start":290,"end":344}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q99963","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q99963-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q99963-F1-predicted_aligned_error_v6.png","plddt_mean":88.31},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=SH3GL3","jax_strain_url":"https://www.jax.org/strain/search?query=SH3GL3"},"sequence":{"accession":"Q99963","fasta_url":"https://rest.uniprot.org/uniprotkb/Q99963.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q99963/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q99963"}},"corpus_meta":[{"pmid":"9238017","id":"PMC_9238017","title":"The SH3p4/Sh3p8/SH3p13 protein family: binding partners for synaptojanin and dynamin via a Grb2-like Src homology 3 domain.","date":"1997","source":"Proceedings of the National Academy of Sciences of the United States of America","url":"https://pubmed.ncbi.nlm.nih.gov/9238017","citation_count":335,"is_preprint":false},{"pmid":"9809064","id":"PMC_9809064","title":"SH3GL3 associates with the Huntingtin exon 1 protein and promotes the formation of polygln-containing protein aggregates.","date":"1998","source":"Molecular cell","url":"https://pubmed.ncbi.nlm.nih.gov/9809064","citation_count":177,"is_preprint":false},{"pmid":"21722156","id":"PMC_21722156","title":"Identification and functional validation of CDH11, PCSK6 and SH3GL3 as novel glioma invasion-associated candidate genes.","date":"2012","source":"Neuropathology and applied neurobiology","url":"https://pubmed.ncbi.nlm.nih.gov/21722156","citation_count":40,"is_preprint":false},{"pmid":"19545932","id":"PMC_19545932","title":"Interaction of SH3P13 and DYDC1 protein: a germ cell component that regulates acrosome biogenesis during spermiogenesis.","date":"2009","source":"European journal of cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/19545932","citation_count":23,"is_preprint":false},{"pmid":"27683032","id":"PMC_27683032","title":"The role of SH3GL3 in myeloma cell migration/invasion, stemness and chemo-resistance.","date":"2016","source":"Oncotarget","url":"https://pubmed.ncbi.nlm.nih.gov/27683032","citation_count":19,"is_preprint":false},{"pmid":"33168185","id":"PMC_33168185","title":"SH3GL3 functions as a potent tumor suppressor in lung cancer in a SH3 domain dependent manner.","date":"2020","source":"Biochemical and biophysical research communications","url":"https://pubmed.ncbi.nlm.nih.gov/33168185","citation_count":18,"is_preprint":false},{"pmid":"37916731","id":"PMC_37916731","title":"LncRNA MIR210HG promotes the proliferation, migration, and invasion of lung cancer cells by inhibiting the transcription of SH3GL3.","date":"2023","source":"The Kaohsiung journal of medical sciences","url":"https://pubmed.ncbi.nlm.nih.gov/37916731","citation_count":10,"is_preprint":false},{"pmid":"33524871","id":"PMC_33524871","title":"SH3GL3 acts as a novel tumor suppressor in glioblastoma tumorigenesis by inhibiting STAT3 signaling.","date":"2021","source":"Biochemical and biophysical research communications","url":"https://pubmed.ncbi.nlm.nih.gov/33524871","citation_count":7,"is_preprint":false},{"pmid":"9878254","id":"PMC_9878254","title":"Characterization of the mouse Src homology 3 domain gene Sh3d2c on Chr 7 demonstrates coexpression with huntingtin in the brain and identifies the processed pseudogene Sh3d2c-ps1 on Chr 2.","date":"1998","source":"Genomics","url":"https://pubmed.ncbi.nlm.nih.gov/9878254","citation_count":7,"is_preprint":false},{"pmid":"40120906","id":"PMC_40120906","title":"Molecular mechanism of SH3GL3 recombinant protein and attenuates the acute lung inflammation in Klebsiella pneumonia rats by mollugin treatment by regulating STAT3/ROS signaling pathway.","date":"2025","source":"International journal of biological macromolecules","url":"https://pubmed.ncbi.nlm.nih.gov/40120906","citation_count":1,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":7058,"output_tokens":2181,"usd":0.026944,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":9208,"output_tokens":2870,"usd":0.058895,"stage2_stop_reason":"end_turn"},"total_usd":0.085839,"stage1_batch_id":"msgbatch_013LWZZT6MWaqB9qyTSeQBmU","stage2_batch_id":"msgbatch_0194ZzQaTGNpruoNJBbEMbt3","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 1997,\n      \"finding\": \"SH3GL3 (SH3p13) binds to both synaptojanin and dynamin I via its SH3 domain (closely related to the Grb2 SH3 domain), and pools of synaptojanin and dynamin I were co-precipitated from brain extracts with anti-SH3p4/8/13 antibodies; the proteins are concentrated in nerve terminals, implicating SH3GL3 in synaptic vesicle recycling.\",\n      \"method\": \"Yeast two-hybrid screen (rat brain library), co-immunoprecipitation from brain extracts, immunolocalization\",\n      \"journal\": \"Proceedings of the National Academy of Sciences of the United States of America\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal Co-IP from native brain tissue plus yeast two-hybrid identification, replicated across three family members and confirmed biochemically\",\n      \"pmids\": [\"9238017\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1998,\n      \"finding\": \"SH3GL3 selectively interacts with the Huntingtin exon 1 protein (HDex1p) bearing a pathological-length polyglutamine repeat; the C-terminal SH3 domain of SH3GL3 and the proline-rich region of HDex1p are essential for this interaction. SH3GL3 promotes the formation of insoluble polyglutamine-containing aggregates in vivo, and co-immunoprecipitation confirmed association with full-length huntingtin from HD human brain extract.\",\n      \"method\": \"Co-immunoprecipitation (COS cell transfection and HD human brain extract), immunofluorescence co-localization, domain-deletion mutagenesis, in vivo aggregation assay\",\n      \"journal\": \"Molecular cell\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal Co-IP in both transfected cells and human brain extract, supported by mutagenesis defining essential domains and co-localization, multiple orthogonal methods in one study\",\n      \"pmids\": [\"9809064\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2009,\n      \"finding\": \"The BAR domain of SH3GL3 (SH3P13) interacts with DYDC1 (identified by yeast two-hybrid from a human testis library); SH3GL3 assists in regulating clathrin-coated vesicle traffic crucial for acrosome biogenesis during spermatogenesis.\",\n      \"method\": \"Yeast two-hybrid screen (human testis library using BAR domain as bait), RNA interference knockdown, germ cell transplantation\",\n      \"journal\": \"European journal of cell biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — yeast two-hybrid plus functional RNAi knockdown demonstrating acrosome biogenesis defect, but interaction not confirmed by orthogonal biochemical method in this abstract\",\n      \"pmids\": [\"19545932\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"Knockdown of SH3GL3 inhibits glioma cell invasion in vitro, establishing a functional role for SH3GL3 in glioma cell invasive behavior.\",\n      \"method\": \"shRNA knockdown, in vitro invasion assay\",\n      \"journal\": \"Neuropathology and applied neurobiology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 / Moderate — clean KD with defined cellular phenotype (invasion assay), confirmed alongside two other candidate genes but limited mechanistic depth\",\n      \"pmids\": [\"21722156\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"SH3GL3 promotes myeloma cell migration/invasion, stemness, and chemo-resistance; overexpression increases p-FAK and p-PI3K levels, and pharmacological inhibition of FAK or PI3K attenuates SH3GL3-mediated migration/invasion, placing SH3GL3 upstream of the FAK/PI3K signaling pathway in myeloma cells.\",\n      \"method\": \"shRNA knockdown, cDNA overexpression, FAK inhibitor and PI3K inhibitor (LY294002) treatment, migration/invasion assay, Western blot for p-FAK/p-PI3K\",\n      \"journal\": \"Oncotarget\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 / Moderate — gain- and loss-of-function with pathway inhibitor rescue, single lab, two orthogonal approaches (OE + KD) plus pharmacological epistasis\",\n      \"pmids\": [\"27683032\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"SH3GL3 inhibits lung cancer cell proliferation, migration, and stem cell self-renewal in an SH3-domain-dependent manner, and upregulates p21 at the transcriptional level; loss of the SH3 domain abolishes these tumor-suppressive effects.\",\n      \"method\": \"Overexpression with SH3-domain deletion mutants, proliferation/migration assays, cell cycle analysis, apoptosis assay, qRT-PCR for p21\",\n      \"journal\": \"Biochemical and biophysical research communications\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 / Moderate — domain-deletion mutagenesis defining SH3 domain requirement plus multiple functional readouts, single lab\",\n      \"pmids\": [\"33168185\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"SH3GL3 physically interacts with STAT3 and inhibits STAT3 nuclear localization in glioblastoma cells; overexpression of constitutively active STAT3 (STAT3-C) rescues the growth, migration, and self-renewal defects caused by SH3GL3 overexpression, placing SH3GL3 as a negative regulator upstream of STAT3 nuclear translocation.\",\n      \"method\": \"Co-immunoprecipitation (SH3GL3–STAT3 interaction), ectopic overexpression, constitutively active STAT3 rescue experiment, nuclear localization assay, proliferation/migration/self-renewal assays\",\n      \"journal\": \"Biochemical and biophysical research communications\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — Co-IP plus genetic epistasis rescue with STAT3-C, single lab, two orthogonal methods\",\n      \"pmids\": [\"33524871\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"The lncRNA MIR210HG recruits DNMT1 to the SH3GL3 promoter region, leading to methylation-mediated transcriptional repression of SH3GL3 in lung cancer cells; knockdown of MIR210HG or overexpression of SH3GL3 suppresses lung cancer cell proliferation, migration, and invasion.\",\n      \"method\": \"Chromatin immunoprecipitation (DNMT1 binding to SH3GL3 promoter), RNA immunoprecipitation (MIR210HG–DNMT1 interaction), methylation-specific PCR, shRNA knockdown, overexpression, functional assays\",\n      \"journal\": \"The Kaohsiung journal of medical sciences\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — ChIP and RIP defining epigenetic mechanism at SH3GL3 promoter, single lab, two orthogonal molecular methods\",\n      \"pmids\": [\"37916731\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"SH3GL3 is a BAR- and SH3-domain-containing endophilin-family protein that, via its SH3 domain, binds synaptojanin and dynamin I at nerve terminals to facilitate synaptic vesicle recycling, interacts with the proline-rich region of polyglutamine-expanded huntingtin to promote aggregate formation, and binds DYDC1 through its BAR domain to regulate acrosome biogenesis; in cancer contexts SH3GL3 acts as a tumor suppressor by inhibiting STAT3 nuclear translocation, transcriptionally upregulating p21, and suppressing FAK/PI3K signaling, while its own transcription is silenced by DNMT1 recruited by the lncRNA MIR210HG.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"SH3GL3 is an SH3- and BAR-domain endophilin-family protein that operates in membrane-trafficking at nerve terminals and acts as a context-dependent regulator of cell growth and invasion in cancer [#0, #6]. At the synapse, its SH3 domain binds synaptojanin and dynamin I, with which it co-precipitates from brain extracts and co-concentrates at nerve terminals, implicating it in synaptic vesicle recycling [#0]. The same SH3 domain selectively engages the proline-rich region of polyglutamine-expanded huntingtin exon 1, an interaction confirmed in transfected cells and HD brain extract, through which SH3GL3 promotes the formation of insoluble polyglutamine aggregates [#1]. Its BAR domain mediates a distinct interaction with DYDC1 that supports clathrin-coated vesicle traffic during acrosome biogenesis in spermatogenesis [#2]. In tumor contexts SH3GL3 has opposing reported roles: in glioblastoma and lung cancer it acts as a tumor suppressor, physically binding STAT3 to block its nuclear translocation and transcriptionally upregulating p21 in an SH3-domain-dependent manner, thereby restraining proliferation, migration, and stem-cell self-renewal [#5, #6], and its own promoter is silenced by DNMT1 recruited via the lncRNA MIR210HG [#7]; conversely, in myeloma and glioma it promotes invasion, with overexpression activating FAK/PI3K signaling [#3, #4].\",\n  \"teleology\": [\n    {\n      \"year\": 1997,\n      \"claim\": \"Established SH3GL3's first molecular partners and a synaptic function by showing its SH3 domain captures the vesicle-trafficking machinery.\",\n      \"evidence\": \"Yeast two-hybrid from rat brain library plus reciprocal Co-IP from brain extracts and immunolocalization at nerve terminals\",\n      \"pmids\": [\"9238017\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"Direct demonstration that SH3GL3 loss impairs vesicle recycling not shown\",\n        \"Functional contribution relative to other endophilin family members not resolved\"\n      ]\n    },\n    {\n      \"year\": 1998,\n      \"claim\": \"Linked SH3GL3 to Huntington disease pathology by showing it binds expanded huntingtin and drives aggregate formation, defining the essential interacting domains.\",\n      \"evidence\": \"Co-IP in transfected COS cells and HD human brain extract, domain-deletion mutagenesis, and in vivo aggregation assay\",\n      \"pmids\": [\"9809064\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"Whether SH3GL3 modifies HD pathology in vivo not established\",\n        \"Mechanism by which the interaction nucleates insoluble aggregates not defined\"\n      ]\n    },\n    {\n      \"year\": 2009,\n      \"claim\": \"Revealed a BAR-domain-mediated function distinct from SH3-domain partnerships, connecting SH3GL3 to acrosome biogenesis via DYDC1.\",\n      \"evidence\": \"Yeast two-hybrid (BAR domain bait, testis library), RNAi knockdown, and germ cell transplantation\",\n      \"pmids\": [\"19545932\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"BAR-domain–DYDC1 interaction not confirmed by an orthogonal biochemical method\",\n        \"Molecular link between DYDC1 binding and clathrin-coated vesicle traffic unresolved\"\n      ]\n    },\n    {\n      \"year\": 2012,\n      \"claim\": \"Extended SH3GL3 function into cancer by showing it is required for glioma cell invasion.\",\n      \"evidence\": \"shRNA knockdown with in vitro invasion assay\",\n      \"pmids\": [\"21722156\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"No molecular mechanism for the invasion phenotype\",\n        \"Studied as one of several candidates with limited depth\"\n      ]\n    },\n    {\n      \"year\": 2016,\n      \"claim\": \"Placed SH3GL3 upstream of FAK/PI3K signaling as a pro-invasive, pro-stemness factor in myeloma, contrasting with later tumor-suppressor findings.\",\n      \"evidence\": \"Gain- and loss-of-function plus FAK/PI3K inhibitor epistasis with migration/invasion assays and Western blot for p-FAK/p-PI3K\",\n      \"pmids\": [\"27683032\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Whether SH3GL3 directly activates FAK/PI3K or acts indirectly unknown\",\n        \"Tissue context driving oncogenic vs tumor-suppressive behavior unexplained\"\n      ]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Defined SH3GL3 as a tumor suppressor in lung cancer that requires its SH3 domain and transcriptionally upregulates p21.\",\n      \"evidence\": \"SH3-domain deletion mutants with proliferation/migration, cell cycle, apoptosis assays and qRT-PCR for p21\",\n      \"pmids\": [\"33168185\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Direct mechanism connecting the SH3 domain to p21 transcription not established\",\n        \"Single-lab evidence without in vivo validation\"\n      ]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"Identified a mechanism for tumor suppression: SH3GL3 binds STAT3 and blocks its nuclear translocation in glioblastoma.\",\n      \"evidence\": \"Co-IP of SH3GL3–STAT3, nuclear localization assay, and constitutively active STAT3-C rescue of growth/migration/self-renewal\",\n      \"pmids\": [\"33524871\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Domain mediating STAT3 binding not mapped\",\n        \"How cytoplasmic sequestration of STAT3 is achieved mechanistically unclear\"\n      ]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Explained how SH3GL3 is silenced in tumors, showing lncRNA MIR210HG recruits DNMT1 to methylate the SH3GL3 promoter.\",\n      \"evidence\": \"ChIP for DNMT1 at the SH3GL3 promoter, RIP for MIR210HG–DNMT1, methylation-specific PCR, and knockdown/overexpression functional assays\",\n      \"pmids\": [\"37916731\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Generality of this silencing axis across tumor types not established\",\n        \"Whether promoter methylation is the dominant in vivo regulator unknown\"\n      ]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"It remains unresolved what determines whether SH3GL3 acts as a tumor suppressor or a pro-invasive factor, and how its synaptic/trafficking functions relate to its signaling roles in cancer.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"No structural model integrating BAR- and SH3-domain functions\",\n        \"Context dependence of oncogenic vs tumor-suppressive behavior unexplained\",\n        \"Physiological relevance of synaptic functions in non-neuronal disease contexts unknown\"\n      ]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0008092\", \"supporting_discovery_ids\": [0, 1]},\n      {\"term_id\": \"GO:0098772\", \"supporting_discovery_ids\": [6]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005886\", \"supporting_discovery_ids\": [0]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-5653656\", \"supporting_discovery_ids\": [0, 2]},\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [4, 6]}\n    ],\n    \"complexes\": [],\n    \"partners\": [\"SYNJ1\", \"DNM1\", \"HTT\", \"DYDC1\", \"STAT3\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":5,"faith_total":5,"faith_pct":100.0}}