{"gene":"KLHL17","run_date":"2026-06-10T02:59:49","timeline":{"discoveries":[{"year":2020,"finding":"KLHL17/Actinfilin localizes to circular puncta in dendritic spines adjacent to F-actin and is required for F-actin enrichment and dendritic spine enlargement (but not spine density or length). Both the N-terminal BTB domain and C-terminal Kelch domains are required for F-actin remodeling at spines. Klhl17 knockout/knockdown reduces postsynaptic and presynaptic markers and alters mEPSC profiles, indicating impaired synaptic activity.","method":"Fluorescent immunostaining, knockdown/knockout in cultured hippocampal neurons, expression of truncated fragments (BTB-only, Kelch-only), electrophysiological recording (mEPSC), mouse behavioral assays","journal":"Journal of biomedical science","confidence":"High","confidence_rationale":"Tier 2 / Strong — multiple orthogonal methods (imaging, domain-deletion mapping, electrophysiology, behavioral assays) in a single focused study with KO/KD controls","pmids":["33256713"],"is_preprint":false},{"year":2023,"finding":"KLHL17 expression is regulated by neuronal activity and KLHL17 controls the synaptic distribution of synaptopodin (SYNPO), a marker of the spine apparatus (a specialized ER compartment in dendritic spines). Super-resolution expansion microscopy shows KLHL17 is closely adjacent to the ER/SYNPO complex. Klhl17 haploinsufficiency and knockout reduce the proportion of dendritic spines containing ER clusters and alter calcium events at spines, impairing activity-dependent spine enlargement and neuronal activation (ERK phosphorylation, C-FOS expression). Disrupting the KLHL17–SYNPO association phenocopies Klhl17 loss.","method":"Mouse genetic models (haploinsufficiency, knockout), super-resolution expansion microscopy, calcium imaging, ERK phosphorylation/C-FOS immunostaining, genetic disruption of KLHL17–SYNPO interaction","journal":"PLoS biology","confidence":"High","confidence_rationale":"Tier 2 / Strong — multiple orthogonal methods (super-resolution imaging, genetic models, calcium imaging, signaling readouts) in a single focused study with mechanistic follow-up","pmids":["37651441"],"is_preprint":false},{"year":2024,"finding":"KLHL17 interacts with N-ethylmaleimide-sensitive fusion protein (NSF) in neurons (identified by proteomics); this interaction stabilizes NSF protein levels. Consistent with NSF's role in AMPAR surface trafficking, Klhl17 deficiency reduces surface (but not total) AMPAR expression and impairs synaptic F-actin distribution and dendritic spine enlargement via the NSF pathway. Separately, KLHL17 acts as a CUL3 ubiquitin ligase adaptor to mediate activity-dependent degradation of the kainate receptor subunit GluK2; Klhl17 deficiency impairs GluK2 degradation and GluK2 contributes to increased calcium influx amplitude and to dendritic spine enlargement defects in Klhl17-deficient neurons.","method":"Proteomics (KLHL17–NSF interaction), surface biotinylation (AMPAR surface expression), knockdown/knockout in hippocampal neurons, calcium imaging, CUL3 complex biochemistry","journal":"Journal of neurochemistry","confidence":"High","confidence_rationale":"Tier 2 / Moderate — proteomics-identified interaction confirmed with functional readouts (surface AMPAR, calcium imaging, spine morphology), two distinct receptor mechanisms tested in same study","pmids":["38898681"],"is_preprint":false},{"year":2024,"finding":"Proteomic analysis in PDAC-derived cells identifies KLHL17 as a member of the Cullin-E3 ubiquitin ligase complex, with vimentin and nestin as candidate substrates for degradation.","method":"Proteomic analysis (mass spectrometry) in PDAC-derived cells","journal":"Nature communications","confidence":"Medium","confidence_rationale":"Tier 3 / Weak — single proteomic identification of complex membership; substrates proposed but not biochemically validated in the abstract","pmids":["40307206"],"is_preprint":false},{"year":2022,"finding":"Overexpression of KLHL17 in NSCLC cell lines promotes proliferation and migration with elevated Ras/MAPK signaling and increased cyclin D1, CDK4, MMP2, and RhoA; KLHL17 knockdown suppresses these effects. Treatment with Ras inhibitor salirasib prevents KLHL17-induced Ras/MAPK activity and tumor proliferation/migration, placing KLHL17 upstream of Ras/MAPK in this cellular context.","method":"KLHL17-Flag overexpression, siRNA knockdown, Ras inhibitor (salirasib) treatment, proliferation/migration assays, western blotting for pathway markers in NSCLC cell lines","journal":"Laboratory investigation","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — gain- and loss-of-function plus pharmacological inhibition in multiple cell lines, but pathway placement is phenotypic/correlative without direct biochemical substrate identification","pmids":["35978057"],"is_preprint":false}],"current_model":"KLHL17 (Actinfilin) is a brain-enriched actin-associated adaptor protein that functions as a CUL3 ubiquitin ligase adaptor (using its BTB and Kelch domains) to control dendritic spine enlargement through at least two mechanisms: (1) stabilizing NSF to promote AMPAR surface expression, and (2) mediating activity-dependent GluK2 (kainate receptor) degradation; it also regulates spine apparatus ER clustering by controlling the synaptic distribution of synaptopodin (SYNPO), thereby gating activity-dependent spine enlargement, calcium signaling, and ERK-dependent neuronal activation. In non-neuronal contexts, KLHL17 has been identified as a component of Cullin-E3 ubiquitin ligase complexes and can activate Ras/MAPK signaling to promote cell proliferation and migration."},"narrative":{"mechanistic_narrative":"KLHL17 (Actinfilin) is a brain-enriched, actin-associated adaptor protein that governs activity-dependent dendritic spine enlargement and synaptic function [PMID:33256713]. It localizes to circular puncta in dendritic spines adjacent to F-actin, and both its N-terminal BTB and C-terminal Kelch domains are required to drive F-actin enrichment and spine enlargement, with its loss reducing synaptic markers and altering mEPSC profiles [PMID:33256713]. KLHL17 functions as a CUL3 ubiquitin ligase adaptor and operates through at least two receptor-directed mechanisms: it stabilizes NSF to support surface AMPAR expression, and it mediates activity-dependent degradation of the kainate receptor subunit GluK2, which otherwise contributes to excess calcium influx and impaired spine enlargement when degradation fails [PMID:38898681]. KLHL17 expression is itself regulated by neuronal activity, and it controls the synaptic distribution of synaptopodin (SYNPO), positioning the spine apparatus (an ER compartment) within spines; disrupting the KLHL17–SYNPO association phenocopies KLHL17 loss, impairing calcium events, activity-dependent spine enlargement, and downstream ERK phosphorylation and C-FOS induction [PMID:37651441]. In non-neuronal contexts, KLHL17 has been identified as a component of Cullin-E3 ubiquitin ligase complexes [PMID:40307206] and promotes proliferation and migration via Ras/MAPK signaling in cancer cell lines [PMID:35978057].","teleology":[{"year":2020,"claim":"Established KLHL17 as a domain-dependent regulator of actin remodeling and dendritic spine morphology, defining its core synaptic function before any molecular partners were known.","evidence":"Immunostaining, knockdown/knockout, domain-deletion mapping (BTB-only, Kelch-only), mEPSC recording and behavioral assays in hippocampal neurons and mice","pmids":["33256713"],"confidence":"High","gaps":["Molecular partners mediating F-actin remodeling not identified","Whether spine enlargement depends on ubiquitin ligase activity not yet addressed","Mechanism linking BTB/Kelch domains to actin not defined"]},{"year":2023,"claim":"Connected KLHL17 to the spine apparatus by showing it controls synaptopodin distribution, explaining how it gates activity-dependent spine enlargement and downstream signaling.","evidence":"Mouse haploinsufficiency/knockout, super-resolution expansion microscopy, calcium imaging, ERK/C-FOS readouts, and genetic disruption of the KLHL17–SYNPO interaction","pmids":["37651441"],"confidence":"High","gaps":["Whether KLHL17 ubiquitinates SYNPO or acts non-catalytically unclear","Direct biochemical nature of the KLHL17–SYNPO association not resolved","How activity regulates KLHL17 expression not defined"]},{"year":2024,"claim":"Identified two distinct receptor-directed mechanisms — NSF stabilization for AMPAR surface trafficking and CUL3-dependent GluK2 degradation — establishing KLHL17 as a ubiquitin ligase adaptor coupling receptor handling to spine enlargement.","evidence":"Proteomics, surface biotinylation, knockdown/knockout in hippocampal neurons, calcium imaging, and CUL3 complex biochemistry","pmids":["38898681"],"confidence":"High","gaps":["Mechanism by which KLHL17 stabilizes rather than degrades NSF unclear","Direct ubiquitination of GluK2 versus indirect effect not fully resolved","How the NSF and GluK2 arms are coordinated within one adaptor unknown"]},{"year":2024,"claim":"Extended KLHL17 beyond neurons by placing it in Cullin-E3 ligase complexes in cancer cells with candidate cytoskeletal substrates, suggesting a broader adaptor role.","evidence":"Mass spectrometry proteomics in PDAC-derived cells","pmids":["40307206"],"confidence":"Medium","gaps":["Vimentin and nestin substrates not biochemically validated","Single proteomic identification without functional follow-up","Relevance to PDAC biology untested"]},{"year":2022,"claim":"Linked KLHL17 to Ras/MAPK-driven proliferation and migration in lung cancer cells, indicating a pro-tumorigenic signaling role distinct from its neuronal function.","evidence":"Overexpression, siRNA knockdown, salirasib Ras inhibition, proliferation/migration assays and pathway western blots in NSCLC cell lines","pmids":["35978057"],"confidence":"Medium","gaps":["Pathway placement is phenotypic/correlative without a direct biochemical substrate","Whether ubiquitin ligase activity drives the Ras/MAPK effect unknown","Direct molecular link between KLHL17 and Ras not established"]},{"year":null,"claim":"How KLHL17's ubiquitin ligase adaptor activity is mechanistically integrated across its multiple targets (NSF, GluK2, SYNPO) and reconciled between neuronal and oncogenic contexts remains unresolved.","evidence":"","pmids":[],"confidence":"Low","gaps":["No unifying model linking actin remodeling, receptor trafficking, and ER clustering","No structural characterization of the BTB/Kelch–CUL3 assembly in any context","Direct ubiquitination substrates not comprehensively validated"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0140096","term_label":"catalytic activity, acting on a protein","supporting_discovery_ids":[2]},{"term_id":"GO:0060090","term_label":"molecular adaptor activity","supporting_discovery_ids":[0,2]},{"term_id":"GO:0008092","term_label":"cytoskeletal protein binding","supporting_discovery_ids":[0]}],"localization":[{"term_id":"GO:0005856","term_label":"cytoskeleton","supporting_discovery_ids":[0]}],"pathway":[],"complexes":["CUL3 ubiquitin ligase complex","Cullin-E3 ubiquitin ligase complex"],"partners":["CUL3","NSF","SYNPO","GLUK2"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q6TDP4","full_name":"Kelch-like protein 17","aliases":["Actinfilin"],"length_aa":642,"mass_kda":69.9,"function":"Substrate-recognition component of some cullin-RING-based BCR (BTB-CUL3-RBX1) E3 ubiquitin-protein ligase complexes. The BCR(KLHL17) complex mediates the ubiquitination and subsequent degradation of GLUR6. May play a role in the actin-based neuronal function (By similarity)","subcellular_location":"Postsynaptic density; Synapse","url":"https://www.uniprot.org/uniprotkb/Q6TDP4/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/KLHL17","classification":"Not Classified","n_dependent_lines":3,"n_total_lines":1208,"dependency_fraction":0.0024834437086092716},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/KLHL17","total_profiled":1310},"omim":[{"mim_id":"619262","title":"KELCH-LIKE 17; KLHL17","url":"https://www.omim.org/entry/619262"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Uncertain","locations":[{"location":"Nuclear bodies","reliability":"Uncertain"},{"location":"Nucleoplasm","reliability":"Additional"}],"tissue_specificity":"Low tissue specificity","tissue_distribution":"Detected in many","driving_tissues":[],"url":"https://www.proteinatlas.org/search/KLHL17"},"hgnc":{"alias_symbol":[],"prev_symbol":[]},"alphafold":{"accession":"Q6TDP4","domains":[{"cath_id":"3.30.710.10","chopping":"74-188","consensus_level":"high","plddt":91.4082,"start":74,"end":188},{"cath_id":"1.25.40.420","chopping":"244-322","consensus_level":"high","plddt":94.2304,"start":244,"end":322},{"cath_id":"2.120.10.80","chopping":"340-623","consensus_level":"medium","plddt":97.1286,"start":340,"end":623}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q6TDP4","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q6TDP4-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q6TDP4-F1-predicted_aligned_error_v6.png","plddt_mean":87.25},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=KLHL17","jax_strain_url":"https://www.jax.org/strain/search?query=KLHL17"},"sequence":{"accession":"Q6TDP4","fasta_url":"https://rest.uniprot.org/uniprotkb/Q6TDP4.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q6TDP4/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q6TDP4"}},"corpus_meta":[{"pmid":"21694734","id":"PMC_21694734","title":"Copy number variants and infantile spasms: evidence for abnormalities in ventral forebrain development and pathways of synaptic function.","date":"2011","source":"European journal of human genetics : EJHG","url":"https://pubmed.ncbi.nlm.nih.gov/21694734","citation_count":67,"is_preprint":false},{"pmid":"35978057","id":"PMC_35978057","title":"Upregulation of KLHL17 promotes the proliferation and migration of non-small cell lung cancer by activating the Ras/MAPK signaling pathway.","date":"2022","source":"Laboratory investigation; a journal of technical methods and pathology","url":"https://pubmed.ncbi.nlm.nih.gov/35978057","citation_count":20,"is_preprint":false},{"pmid":"28912426","id":"PMC_28912426","title":"Deconvolution of DNA methylation identifies differentially methylated gene regions on 1p36 across breast cancer subtypes.","date":"2017","source":"Scientific reports","url":"https://pubmed.ncbi.nlm.nih.gov/28912426","citation_count":20,"is_preprint":false},{"pmid":"33256713","id":"PMC_33256713","title":"KLHL17/Actinfilin, a brain-specific gene associated with infantile spasms and autism, regulates dendritic spine enlargement.","date":"2020","source":"Journal of biomedical science","url":"https://pubmed.ncbi.nlm.nih.gov/33256713","citation_count":13,"is_preprint":false},{"pmid":"37651441","id":"PMC_37651441","title":"Autism-related KLHL17 and SYNPO act in concert to control activity-dependent dendritic spine enlargement and the spine apparatus.","date":"2023","source":"PLoS biology","url":"https://pubmed.ncbi.nlm.nih.gov/37651441","citation_count":9,"is_preprint":false},{"pmid":"40307206","id":"PMC_40307206","title":"Allelic effects on KLHL17 expression underlie a pancreatic cancer genome-wide association signal at chr1p36.33.","date":"2025","source":"Nature communications","url":"https://pubmed.ncbi.nlm.nih.gov/40307206","citation_count":4,"is_preprint":false},{"pmid":"38898681","id":"PMC_38898681","title":"KLHL17 differentially controls the expression of AMPA- and KA-type glutamate receptors to regulate dendritic spine enlargement.","date":"2024","source":"Journal of neurochemistry","url":"https://pubmed.ncbi.nlm.nih.gov/38898681","citation_count":3,"is_preprint":false},{"pmid":"39585938","id":"PMC_39585938","title":"Rapid Identification of Ancient Leather Species Using an Enzyme-Linked Immunosorbent Assay Based on Proteomic and Evolutionary Analyses.","date":"2024","source":"Journal of proteome research","url":"https://pubmed.ncbi.nlm.nih.gov/39585938","citation_count":2,"is_preprint":false},{"pmid":"39371158","id":"PMC_39371158","title":"Allelic effects on KLHL17 expression likely mediated by JunB/D underlie a PDAC GWAS signal at chr1p36.33.","date":"2024","source":"medRxiv : the preprint server for health sciences","url":"https://pubmed.ncbi.nlm.nih.gov/39371158","citation_count":0,"is_preprint":false},{"pmid":"42262377","id":"PMC_42262377","title":"Service Year-Dependent Disruption of Reproductive Hormones and Altered DNA Methylation in Male Firefighters.","date":"2026","source":"Journal of occupational and environmental medicine","url":"https://pubmed.ncbi.nlm.nih.gov/42262377","citation_count":0,"is_preprint":false},{"pmid":null,"id":"bio_10.1101_2024.09.16.24313748","title":"Allelic effects on<i>KLHL17</i>expression likely mediated by JunB/D underlie a PDAC GWAS signal at chr1p36.33","date":"2024-09-16","source":"bioRxiv","url":"https://doi.org/10.1101/2024.09.16.24313748","citation_count":0,"is_preprint":true}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":7992,"output_tokens":1683,"usd":0.024611,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":8567,"output_tokens":2469,"usd":0.05228,"stage2_stop_reason":"end_turn"},"total_usd":0.076891,"stage1_batch_id":"msgbatch_01BbTCMyrRPyhtEq6b1MdwCN","stage2_batch_id":"msgbatch_011dEed5bbxYvTAaQWKJevxu","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2020,\n      \"finding\": \"KLHL17/Actinfilin localizes to circular puncta in dendritic spines adjacent to F-actin and is required for F-actin enrichment and dendritic spine enlargement (but not spine density or length). Both the N-terminal BTB domain and C-terminal Kelch domains are required for F-actin remodeling at spines. Klhl17 knockout/knockdown reduces postsynaptic and presynaptic markers and alters mEPSC profiles, indicating impaired synaptic activity.\",\n      \"method\": \"Fluorescent immunostaining, knockdown/knockout in cultured hippocampal neurons, expression of truncated fragments (BTB-only, Kelch-only), electrophysiological recording (mEPSC), mouse behavioral assays\",\n      \"journal\": \"Journal of biomedical science\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — multiple orthogonal methods (imaging, domain-deletion mapping, electrophysiology, behavioral assays) in a single focused study with KO/KD controls\",\n      \"pmids\": [\"33256713\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"KLHL17 expression is regulated by neuronal activity and KLHL17 controls the synaptic distribution of synaptopodin (SYNPO), a marker of the spine apparatus (a specialized ER compartment in dendritic spines). Super-resolution expansion microscopy shows KLHL17 is closely adjacent to the ER/SYNPO complex. Klhl17 haploinsufficiency and knockout reduce the proportion of dendritic spines containing ER clusters and alter calcium events at spines, impairing activity-dependent spine enlargement and neuronal activation (ERK phosphorylation, C-FOS expression). Disrupting the KLHL17–SYNPO association phenocopies Klhl17 loss.\",\n      \"method\": \"Mouse genetic models (haploinsufficiency, knockout), super-resolution expansion microscopy, calcium imaging, ERK phosphorylation/C-FOS immunostaining, genetic disruption of KLHL17–SYNPO interaction\",\n      \"journal\": \"PLoS biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — multiple orthogonal methods (super-resolution imaging, genetic models, calcium imaging, signaling readouts) in a single focused study with mechanistic follow-up\",\n      \"pmids\": [\"37651441\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"KLHL17 interacts with N-ethylmaleimide-sensitive fusion protein (NSF) in neurons (identified by proteomics); this interaction stabilizes NSF protein levels. Consistent with NSF's role in AMPAR surface trafficking, Klhl17 deficiency reduces surface (but not total) AMPAR expression and impairs synaptic F-actin distribution and dendritic spine enlargement via the NSF pathway. Separately, KLHL17 acts as a CUL3 ubiquitin ligase adaptor to mediate activity-dependent degradation of the kainate receptor subunit GluK2; Klhl17 deficiency impairs GluK2 degradation and GluK2 contributes to increased calcium influx amplitude and to dendritic spine enlargement defects in Klhl17-deficient neurons.\",\n      \"method\": \"Proteomics (KLHL17–NSF interaction), surface biotinylation (AMPAR surface expression), knockdown/knockout in hippocampal neurons, calcium imaging, CUL3 complex biochemistry\",\n      \"journal\": \"Journal of neurochemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — proteomics-identified interaction confirmed with functional readouts (surface AMPAR, calcium imaging, spine morphology), two distinct receptor mechanisms tested in same study\",\n      \"pmids\": [\"38898681\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"Proteomic analysis in PDAC-derived cells identifies KLHL17 as a member of the Cullin-E3 ubiquitin ligase complex, with vimentin and nestin as candidate substrates for degradation.\",\n      \"method\": \"Proteomic analysis (mass spectrometry) in PDAC-derived cells\",\n      \"journal\": \"Nature communications\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 / Weak — single proteomic identification of complex membership; substrates proposed but not biochemically validated in the abstract\",\n      \"pmids\": [\"40307206\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"Overexpression of KLHL17 in NSCLC cell lines promotes proliferation and migration with elevated Ras/MAPK signaling and increased cyclin D1, CDK4, MMP2, and RhoA; KLHL17 knockdown suppresses these effects. Treatment with Ras inhibitor salirasib prevents KLHL17-induced Ras/MAPK activity and tumor proliferation/migration, placing KLHL17 upstream of Ras/MAPK in this cellular context.\",\n      \"method\": \"KLHL17-Flag overexpression, siRNA knockdown, Ras inhibitor (salirasib) treatment, proliferation/migration assays, western blotting for pathway markers in NSCLC cell lines\",\n      \"journal\": \"Laboratory investigation\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — gain- and loss-of-function plus pharmacological inhibition in multiple cell lines, but pathway placement is phenotypic/correlative without direct biochemical substrate identification\",\n      \"pmids\": [\"35978057\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"KLHL17 (Actinfilin) is a brain-enriched actin-associated adaptor protein that functions as a CUL3 ubiquitin ligase adaptor (using its BTB and Kelch domains) to control dendritic spine enlargement through at least two mechanisms: (1) stabilizing NSF to promote AMPAR surface expression, and (2) mediating activity-dependent GluK2 (kainate receptor) degradation; it also regulates spine apparatus ER clustering by controlling the synaptic distribution of synaptopodin (SYNPO), thereby gating activity-dependent spine enlargement, calcium signaling, and ERK-dependent neuronal activation. In non-neuronal contexts, KLHL17 has been identified as a component of Cullin-E3 ubiquitin ligase complexes and can activate Ras/MAPK signaling to promote cell proliferation and migration.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"KLHL17 (Actinfilin) is a brain-enriched, actin-associated adaptor protein that governs activity-dependent dendritic spine enlargement and synaptic function [#0]. It localizes to circular puncta in dendritic spines adjacent to F-actin, and both its N-terminal BTB and C-terminal Kelch domains are required to drive F-actin enrichment and spine enlargement, with its loss reducing synaptic markers and altering mEPSC profiles [#0]. KLHL17 functions as a CUL3 ubiquitin ligase adaptor and operates through at least two receptor-directed mechanisms: it stabilizes NSF to support surface AMPAR expression, and it mediates activity-dependent degradation of the kainate receptor subunit GluK2, which otherwise contributes to excess calcium influx and impaired spine enlargement when degradation fails [#2]. KLHL17 expression is itself regulated by neuronal activity, and it controls the synaptic distribution of synaptopodin (SYNPO), positioning the spine apparatus (an ER compartment) within spines; disrupting the KLHL17–SYNPO association phenocopies KLHL17 loss, impairing calcium events, activity-dependent spine enlargement, and downstream ERK phosphorylation and C-FOS induction [#1]. In non-neuronal contexts, KLHL17 has been identified as a component of Cullin-E3 ubiquitin ligase complexes [#3] and promotes proliferation and migration via Ras/MAPK signaling in cancer cell lines [#4].\",\n  \"teleology\": [\n    {\n      \"year\": 2020,\n      \"claim\": \"Established KLHL17 as a domain-dependent regulator of actin remodeling and dendritic spine morphology, defining its core synaptic function before any molecular partners were known.\",\n      \"evidence\": \"Immunostaining, knockdown/knockout, domain-deletion mapping (BTB-only, Kelch-only), mEPSC recording and behavioral assays in hippocampal neurons and mice\",\n      \"pmids\": [\"33256713\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"Molecular partners mediating F-actin remodeling not identified\",\n        \"Whether spine enlargement depends on ubiquitin ligase activity not yet addressed\",\n        \"Mechanism linking BTB/Kelch domains to actin not defined\"\n      ]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Connected KLHL17 to the spine apparatus by showing it controls synaptopodin distribution, explaining how it gates activity-dependent spine enlargement and downstream signaling.\",\n      \"evidence\": \"Mouse haploinsufficiency/knockout, super-resolution expansion microscopy, calcium imaging, ERK/C-FOS readouts, and genetic disruption of the KLHL17–SYNPO interaction\",\n      \"pmids\": [\"37651441\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"Whether KLHL17 ubiquitinates SYNPO or acts non-catalytically unclear\",\n        \"Direct biochemical nature of the KLHL17–SYNPO association not resolved\",\n        \"How activity regulates KLHL17 expression not defined\"\n      ]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Identified two distinct receptor-directed mechanisms — NSF stabilization for AMPAR surface trafficking and CUL3-dependent GluK2 degradation — establishing KLHL17 as a ubiquitin ligase adaptor coupling receptor handling to spine enlargement.\",\n      \"evidence\": \"Proteomics, surface biotinylation, knockdown/knockout in hippocampal neurons, calcium imaging, and CUL3 complex biochemistry\",\n      \"pmids\": [\"38898681\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"Mechanism by which KLHL17 stabilizes rather than degrades NSF unclear\",\n        \"Direct ubiquitination of GluK2 versus indirect effect not fully resolved\",\n        \"How the NSF and GluK2 arms are coordinated within one adaptor unknown\"\n      ]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Extended KLHL17 beyond neurons by placing it in Cullin-E3 ligase complexes in cancer cells with candidate cytoskeletal substrates, suggesting a broader adaptor role.\",\n      \"evidence\": \"Mass spectrometry proteomics in PDAC-derived cells\",\n      \"pmids\": [\"40307206\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Vimentin and nestin substrates not biochemically validated\",\n        \"Single proteomic identification without functional follow-up\",\n        \"Relevance to PDAC biology untested\"\n      ]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Linked KLHL17 to Ras/MAPK-driven proliferation and migration in lung cancer cells, indicating a pro-tumorigenic signaling role distinct from its neuronal function.\",\n      \"evidence\": \"Overexpression, siRNA knockdown, salirasib Ras inhibition, proliferation/migration assays and pathway western blots in NSCLC cell lines\",\n      \"pmids\": [\"35978057\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Pathway placement is phenotypic/correlative without a direct biochemical substrate\",\n        \"Whether ubiquitin ligase activity drives the Ras/MAPK effect unknown\",\n        \"Direct molecular link between KLHL17 and Ras not established\"\n      ]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"How KLHL17's ubiquitin ligase adaptor activity is mechanistically integrated across its multiple targets (NSF, GluK2, SYNPO) and reconciled between neuronal and oncogenic contexts remains unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\n        \"No unifying model linking actin remodeling, receptor trafficking, and ER clustering\",\n        \"No structural characterization of the BTB/Kelch–CUL3 assembly in any context\",\n        \"Direct ubiquitination substrates not comprehensively validated\"\n      ]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0140096\", \"supporting_discovery_ids\": [2]},\n      {\"term_id\": \"GO:0060090\", \"supporting_discovery_ids\": [0, 2]},\n      {\"term_id\": \"GO:0008092\", \"supporting_discovery_ids\": [0]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005856\", \"supporting_discovery_ids\": [0]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"GO:0112316\", \"supporting_discovery_ids\": []}\n    ],\n    \"complexes\": [\"CUL3 ubiquitin ligase complex\", \"Cullin-E3 ubiquitin ligase complex\"],\n    \"partners\": [\"CUL3\", \"NSF\", \"SYNPO\", \"GluK2\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":5,"faith_total":5,"faith_pct":100.0}}