{"gene":"AP5Z1","run_date":"2026-06-09T22:02:43","timeline":{"discoveries":[{"year":2010,"finding":"KIAA0415/SPG48 (AP5Z1) encodes a putative helicase that physically interacts with SPG11 and SPG15, forming a novel protein complex; knockdown of KIAA0415 decreased the frequency of homologous recombination DNA double-strand break repair (HR-DSBR), and a KIAA0415 mutant cell line showed increased sensitivity to DNA-damaging drugs.","method":"Genome-scale esiRNA screen for HR-DSBR; protein interaction assay (pulldown/co-IP with SPG11 and SPG15); sensitivity assay with DNA-damaging agents in mutant cell line","journal":"PLoS biology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — functional esiRNA screen plus protein interaction assay and drug-sensitivity phenotype, single lab but multiple orthogonal methods","pmids":["20613862"],"is_preprint":false},{"year":2016,"finding":"Complete loss of AP-5 ζ protein (AP5Z1) in patient fibroblasts leads to accumulation of PAS-positive and autofluorescent storage material and lamellar lysosomal storage material visible by electron microscopy, indicating AP5Z1 is required for normal lysosomal homeostasis.","method":"Western blot (protein loss confirmation); PAS staining and autofluorescence assay; electron microscopy of skin fibroblasts from patients with biallelic AP5Z1 mutations","journal":"Neurology. Genetics","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — multiple orthogonal methods (WB, histochemistry, EM) in patient-derived cells, single lab","pmids":["27606357"],"is_preprint":false},{"year":2019,"finding":"AP5 ζ (AP5Z1) knockout in mouse causes age-dependent degeneration of corticospinal axons; knockout fibroblasts show a trafficking defect from late endosomes to the trans-Golgi network, structural Golgi defects, impaired autophagic flux, and impaired recycling of lysosomes from autolysosomes; in vivo, neurons accumulate autophagosomes, autolysosomes, and intracellular waste.","method":"AP5Z1 knockout mouse model; cell fractionation/trafficking assays in knockout fibroblasts; Golgi morphology analysis; autophagic flux assays (LC3-II accumulation, lysosome recycling); in vivo histopathology","journal":"Neurobiology of disease","confidence":"High","confidence_rationale":"Tier 2 / Strong — genetic KO model with multiple orthogonal cellular assays (trafficking, Golgi, autophagy) and in vivo neuropathology, consistent mechanistic picture","pmids":["30930081"],"is_preprint":false},{"year":2023,"finding":"Spatacsin (SPG11) promotes the degradation of AP5Z1 at lysosomes, thereby regulating the relative amounts of spastizin and AP5Z1 at the lysosomal surface; AP5Z1 interacts with the retrograde motor dynein/dynactin subunit p150Glued, while spastizin interacts with anterograde motor KIF13A; together they control tubular lysosome formation and the directionality of lysosome trafficking in neurons.","method":"Co-immunoprecipitation of AP5Z1 with p150Glued and spastizin with KIF13A; protein degradation assays in mouse brain extracts and mouse embryonic fibroblasts; spatacsin knockdown/rescue experiments; live imaging of tubular lysosomes in polarized cortical neurons","journal":"PLoS biology","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal Co-IP for motor interactions, functional degradation assays, live-imaging in neurons, multiple orthogonal methods in one study","pmids":["37871017"],"is_preprint":false},{"year":2025,"finding":"Disruption of Ap5z1 (AP5Z1 ζ-subunit) in mouse BMDMs sensitizes the non-canonical inflammasome, resulting in a stronger inflammatory response; mass spectrometry of activated BMDMs from Spg11 KO mice reveals massive downregulation of AP5 subunits including AP5Z1, linking the AP5 complex to non-canonical inflammasome regulation in innate immune cells.","method":"Ap5z1 knockout mouse; inflammasome activation assays in primary microglia and BMDMs; mass spectrometry of activated BMDMs; in vivo LPS challenge","journal":"EBioMedicine","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — genetic KO with functional inflammasome readout and MS proteomics, single lab","pmids":["41138668"],"is_preprint":false},{"year":2025,"finding":"AP5Z1 promotes ubiquitination and degradation of PTEN by recruiting TRIM21 (an E3 ubiquitin ligase), thereby activating the PI3K/Akt/mTOR pathway and modulating autophagy and apoptosis in hepatocellular carcinoma cells.","method":"Co-immunoprecipitation and mass spectrometry identifying PTEN and TRIM21 as AP5Z1 partners; Western blot for PTEN ubiquitination; cell proliferation, apoptosis (flow cytometry), and autophagy assays; animal model experiments","journal":"Journal of translational medicine","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — Co-IP plus MS plus functional pathway assays in vitro and in vivo, single lab","pmids":["40394639"],"is_preprint":false}],"current_model":"AP5Z1 encodes the ζ subunit of the adaptor protein complex 5 (AP-5), which physically interacts with SPG11 (spatacsin) and SPG15 (spastizin) to form a complex required for late endosome-to-trans-Golgi trafficking, lysosomal recycling from autolysosomes, and autophagic flux; spatacsin promotes AP5Z1 degradation to balance retrograde (AP5Z1–dynein/dynactin) versus anterograde (spastizin–KIF13A) lysosome motility, and AP5Z1 loss blocks autophagy leading to corticospinal axon degeneration; additionally, AP5Z1 promotes PTEN ubiquitination via TRIM21 to activate PI3K/Akt/mTOR signaling and modulate autophagy, and its disruption sensitizes the non-canonical inflammasome in innate immune cells."},"narrative":{"mechanistic_narrative":"AP5Z1 encodes the ζ subunit of the adaptor protein complex 5 (AP-5), which physically associates with SPG11 (spatacsin) and SPG15 (spastizin) to govern endolysosomal membrane traffic and autophagic flux [PMID:20613862, PMID:30930081]. AP-5 mediates retrograde trafficking from late endosomes to the trans-Golgi network and the recycling of lysosomes from autolysosomes; loss of AP5Z1 produces structural Golgi defects, impaired autophagic flux, accumulation of intracellular storage and autofluorescent material, and age-dependent degeneration of corticospinal axons [PMID:27606357, PMID:30930081]. Lysosome trafficking directionality is set by competition between AP5Z1, which binds the retrograde dynein/dynactin subunit p150Glued, and spastizin, which binds the anterograde motor KIF13A, with spatacsin promoting lysosomal degradation of AP5Z1 to balance the two pools [PMID:37871017]. Beyond its trafficking role, AP5Z1 recruits the E3 ligase TRIM21 to drive PTEN ubiquitination and activate PI3K/Akt/mTOR signaling in hepatocellular carcinoma cells [PMID:40394639], and its disruption sensitizes the non-canonical inflammasome in innate immune cells [PMID:41138668]. AP5Z1 knockdown also reduces homologous-recombination double-strand break repair and sensitizes cells to DNA-damaging agents [PMID:20613862].","teleology":[{"year":2010,"claim":"Established that AP5Z1 is not an isolated protein but a stable partner of SPG11 and SPG15, defining a novel complex and linking it to a DNA double-strand break repair phenotype.","evidence":"Genome-scale esiRNA HR-DSBR screen plus co-IP/pulldown with SPG11 and SPG15 and drug-sensitivity assay in mutant cells","pmids":["20613862"],"confidence":"Medium","gaps":["Mechanism connecting the complex to HR-DSBR not resolved","Helicase activity asserted but not biochemically demonstrated","Subunit stoichiometry and architecture undefined"]},{"year":2016,"claim":"Showed that complete loss of AP5Z1 in patient cells causes lysosomal storage pathology, establishing a requirement for AP5Z1 in lysosomal homeostasis.","evidence":"Western blot, PAS staining, autofluorescence, and electron microscopy of fibroblasts from patients with biallelic AP5Z1 mutations","pmids":["27606357"],"confidence":"Medium","gaps":["Molecular trafficking step responsible for storage not identified","Causal chain from storage to neurodegeneration unestablished"]},{"year":2019,"claim":"Defined the trafficking step AP-5 acts on—late endosome-to-TGN transport and lysosome recycling from autolysosomes—and linked its failure to autophagy block and corticospinal axon degeneration.","evidence":"AP5Z1 knockout mouse with fibroblast trafficking and autophagic-flux assays, Golgi morphology analysis, and in vivo neuropathology","pmids":["30930081"],"confidence":"High","gaps":["Direct cargo molecules of AP-5 not enumerated","How autophagy block translates specifically to corticospinal vulnerability unresolved"]},{"year":2023,"claim":"Resolved how AP5Z1 levels and lysosome motility are controlled, showing spatacsin-driven degradation balances AP5Z1-dynein retrograde transport against spastizin-KIF13A anterograde transport.","evidence":"Reciprocal co-IP (AP5Z1-p150Glued, spastizin-KIF13A), degradation assays in brain extracts and MEFs, spatacsin knockdown/rescue, and live imaging of tubular lysosomes in cortical neurons","pmids":["37871017"],"confidence":"High","gaps":["Degradation machinery acting on AP5Z1 not identified","Quantitative rules governing motor switching unknown"]},{"year":2025,"claim":"Extended AP5Z1 function beyond trafficking into signaling, showing it recruits TRIM21 to ubiquitinate PTEN and activate PI3K/Akt/mTOR in liver cancer cells.","evidence":"Co-IP/MS identifying PTEN and TRIM21, PTEN ubiquitination Western blots, proliferation/apoptosis/autophagy assays, and animal models in hepatocellular carcinoma","pmids":["40394639"],"confidence":"Medium","gaps":["Whether this signaling role requires the AP-5 complex or is AP5Z1-independent unclear","Direct versus bridged AP5Z1-TRIM21-PTEN interaction not dissected","Generality beyond HCC untested"]},{"year":2025,"claim":"Connected the AP-5 complex to innate immunity, showing AP5Z1 disruption sensitizes the non-canonical inflammasome and that AP5 subunits are downregulated in activated Spg11-KO macrophages.","evidence":"Ap5z1 knockout mouse, inflammasome activation assays in microglia and BMDMs, mass spectrometry of activated BMDMs, and in vivo LPS challenge","pmids":["41138668"],"confidence":"Medium","gaps":["Molecular mechanism linking AP-5 trafficking to inflammasome restraint unknown","Relevant cargo or membrane compartment not identified"]},{"year":null,"claim":"It remains unknown which membrane cargoes AP-5 selects and how a single complex coordinates endolysosomal trafficking, DNA repair, PI3K/Akt/mTOR signaling, and inflammasome control.","evidence":"No single study in the corpus integrates these roles or identifies direct AP-5 cargo","pmids":[],"confidence":"Medium","gaps":["Direct AP-5 cargo repertoire undefined","Structural basis of subunit assembly unresolved","Whether non-trafficking roles depend on the intact AP-5 complex untested"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0060090","term_label":"molecular adaptor activity","supporting_discovery_ids":[2,3]},{"term_id":"GO:0140096","term_label":"catalytic activity, acting on a protein","supporting_discovery_ids":[5]}],"localization":[{"term_id":"GO:0005764","term_label":"lysosome","supporting_discovery_ids":[1,3]},{"term_id":"GO:0005794","term_label":"Golgi apparatus","supporting_discovery_ids":[2]},{"term_id":"GO:0005768","term_label":"endosome","supporting_discovery_ids":[2]}],"pathway":[{"term_id":"R-HSA-9612973","term_label":"Autophagy","supporting_discovery_ids":[2,5]},{"term_id":"R-HSA-5653656","term_label":"Vesicle-mediated transport","supporting_discovery_ids":[2,3]},{"term_id":"R-HSA-9609507","term_label":"Protein localization","supporting_discovery_ids":[2,3]},{"term_id":"R-HSA-162582","term_label":"Signal Transduction","supporting_discovery_ids":[5]},{"term_id":"R-HSA-168256","term_label":"Immune System","supporting_discovery_ids":[4]}],"complexes":["AP-5 (adaptor protein complex 5)"],"partners":["SPG11","SPG15","DCTN1","KIF13A","TRIM21","PTEN"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"O43299","full_name":"AP-5 complex subunit zeta-1","aliases":["Adaptor-related protein complex 5 zeta subunit","Zeta5"],"length_aa":807,"mass_kda":88.6,"function":"As part of AP-5, a probable fifth adaptor protein complex it may be involved in endosomal transport. According to PubMed:20613862 it is a putative helicase required for efficient homologous recombination DNA double-strand break repair","subcellular_location":"Cytoplasm; Nucleus","url":"https://www.uniprot.org/uniprotkb/O43299/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/AP5Z1","classification":"Not Classified","n_dependent_lines":2,"n_total_lines":1208,"dependency_fraction":0.0016556291390728477},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/AP5Z1","total_profiled":1310},"omim":[{"mim_id":"614824","title":"ADAPTOR-RELATED PROTEIN COMPLEX 5, SIGMA-1 SUBUNIT; AP5S1","url":"https://www.omim.org/entry/614824"},{"mim_id":"613653","title":"ADAPTOR-RELATED PROTEIN COMPLEX 5, ZETA-1 SUBUNIT; AP5Z1","url":"https://www.omim.org/entry/613653"},{"mim_id":"613647","title":"SPASTIC PARAPLEGIA 48, AUTOSOMAL RECESSIVE; SPG48","url":"https://www.omim.org/entry/613647"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Supported","locations":[{"location":"Nuclear speckles","reliability":"Supported"},{"location":"Nucleoplasm","reliability":"Additional"}],"tissue_specificity":"Low tissue specificity","tissue_distribution":"Detected in many","driving_tissues":[],"url":"https://www.proteinatlas.org/search/AP5Z1"},"hgnc":{"alias_symbol":["SPG48","zeta"],"prev_symbol":["KIAA0415"]},"alphafold":{"accession":"O43299","domains":[{"cath_id":"-","chopping":"170-191_212-254_288-311_319-420","consensus_level":"medium","plddt":91.2627,"start":170,"end":420}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/O43299","model_url":"https://alphafold.ebi.ac.uk/files/AF-O43299-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-O43299-F1-predicted_aligned_error_v6.png","plddt_mean":84.88},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=AP5Z1","jax_strain_url":"https://www.jax.org/strain/search?query=AP5Z1"},"sequence":{"accession":"O43299","fasta_url":"https://rest.uniprot.org/uniprotkb/O43299.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/O43299/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/O43299"}},"corpus_meta":[{"pmid":"20613862","id":"PMC_20613862","title":"A genome-scale DNA repair RNAi screen identifies SPG48 as a novel gene associated with hereditary spastic paraplegia.","date":"2010","source":"PLoS biology","url":"https://pubmed.ncbi.nlm.nih.gov/20613862","citation_count":155,"is_preprint":false},{"pmid":"24833714","id":"PMC_24833714","title":"Overlapping phenotypes in complex spastic paraplegias SPG11, SPG15, SPG35 and SPG48.","date":"2014","source":"Brain : a journal of neurology","url":"https://pubmed.ncbi.nlm.nih.gov/24833714","citation_count":132,"is_preprint":false},{"pmid":"27606357","id":"PMC_27606357","title":"Complicated spastic paraplegia in patients with AP5Z1 mutations (SPG48).","date":"2016","source":"Neurology. Genetics","url":"https://pubmed.ncbi.nlm.nih.gov/27606357","citation_count":36,"is_preprint":false},{"pmid":"30930081","id":"PMC_30930081","title":"A mouse model for SPG48 reveals a block of autophagic flux upon disruption of adaptor protein complex five.","date":"2019","source":"Neurobiology of disease","url":"https://pubmed.ncbi.nlm.nih.gov/30930081","citation_count":28,"is_preprint":false},{"pmid":"25333062","id":"PMC_25333062","title":"AP5Z1/SPG48 frequency in autosomal recessive and sporadic spastic paraplegia.","date":"2014","source":"Molecular genetics & genomic medicine","url":"https://pubmed.ncbi.nlm.nih.gov/25333062","citation_count":13,"is_preprint":false},{"pmid":"37871017","id":"PMC_37871017","title":"Spatacsin regulates directionality of lysosome trafficking by promoting the degradation of its partner AP5Z1.","date":"2023","source":"PLoS biology","url":"https://pubmed.ncbi.nlm.nih.gov/37871017","citation_count":8,"is_preprint":false},{"pmid":"40394639","id":"PMC_40394639","title":"AP5Z1 affects hepatocellular carcinoma growth and autophagy by regulating PTEN ubiquitination and modulating the PI3K/Akt/mTOR pathway.","date":"2025","source":"Journal of translational medicine","url":"https://pubmed.ncbi.nlm.nih.gov/40394639","citation_count":6,"is_preprint":false},{"pmid":"32641631","id":"PMC_32641631","title":"[A case of spastic paraplegia 48 with a novel mutation in the AP5Z1 gene].","date":"2020","source":"Rinsho shinkeigaku = Clinical neurology","url":"https://pubmed.ncbi.nlm.nih.gov/32641631","citation_count":4,"is_preprint":false},{"pmid":"39059408","id":"PMC_39059408","title":"Early Diagnosis of AP5Z1/SPG48 Spastic Paraplegia: Case Report and Review of the Literature.","date":"2024","source":"Neuropediatrics","url":"https://pubmed.ncbi.nlm.nih.gov/39059408","citation_count":1,"is_preprint":false},{"pmid":"41138668","id":"PMC_41138668","title":"Hyperactivity of the non-canonical inflammasome in SPG11 and SPG48.","date":"2025","source":"EBioMedicine","url":"https://pubmed.ncbi.nlm.nih.gov/41138668","citation_count":0,"is_preprint":false},{"pmid":"41808431","id":"PMC_41808431","title":"Expanding the Genotypic and Phenotypic Spectrum of AP5Z1-Related Spastic Paraplegia: A Novel Variant and Comprehensive Literature Review.","date":"2026","source":"International journal of developmental neuroscience : the official journal of the International Society for Developmental Neuroscience","url":"https://pubmed.ncbi.nlm.nih.gov/41808431","citation_count":0,"is_preprint":false},{"pmid":"41830174","id":"PMC_41830174","title":"Bi-allelic variants in AP5Z1 and AP5B1 lead to retinal degeneration.","date":"2026","source":"HGG advances","url":"https://pubmed.ncbi.nlm.nih.gov/41830174","citation_count":0,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":8333,"output_tokens":1824,"usd":0.02618,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":8715,"output_tokens":2777,"usd":0.0565,"stage2_stop_reason":"end_turn"},"total_usd":0.08268,"stage1_batch_id":"msgbatch_0179Z2pxRYBsXi2xADneafRw","stage2_batch_id":"msgbatch_01LaY9ZaVdgjWArcZo9eqQE5","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2010,\n      \"finding\": \"KIAA0415/SPG48 (AP5Z1) encodes a putative helicase that physically interacts with SPG11 and SPG15, forming a novel protein complex; knockdown of KIAA0415 decreased the frequency of homologous recombination DNA double-strand break repair (HR-DSBR), and a KIAA0415 mutant cell line showed increased sensitivity to DNA-damaging drugs.\",\n      \"method\": \"Genome-scale esiRNA screen for HR-DSBR; protein interaction assay (pulldown/co-IP with SPG11 and SPG15); sensitivity assay with DNA-damaging agents in mutant cell line\",\n      \"journal\": \"PLoS biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — functional esiRNA screen plus protein interaction assay and drug-sensitivity phenotype, single lab but multiple orthogonal methods\",\n      \"pmids\": [\"20613862\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"Complete loss of AP-5 ζ protein (AP5Z1) in patient fibroblasts leads to accumulation of PAS-positive and autofluorescent storage material and lamellar lysosomal storage material visible by electron microscopy, indicating AP5Z1 is required for normal lysosomal homeostasis.\",\n      \"method\": \"Western blot (protein loss confirmation); PAS staining and autofluorescence assay; electron microscopy of skin fibroblasts from patients with biallelic AP5Z1 mutations\",\n      \"journal\": \"Neurology. Genetics\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple orthogonal methods (WB, histochemistry, EM) in patient-derived cells, single lab\",\n      \"pmids\": [\"27606357\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"AP5 ζ (AP5Z1) knockout in mouse causes age-dependent degeneration of corticospinal axons; knockout fibroblasts show a trafficking defect from late endosomes to the trans-Golgi network, structural Golgi defects, impaired autophagic flux, and impaired recycling of lysosomes from autolysosomes; in vivo, neurons accumulate autophagosomes, autolysosomes, and intracellular waste.\",\n      \"method\": \"AP5Z1 knockout mouse model; cell fractionation/trafficking assays in knockout fibroblasts; Golgi morphology analysis; autophagic flux assays (LC3-II accumulation, lysosome recycling); in vivo histopathology\",\n      \"journal\": \"Neurobiology of disease\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — genetic KO model with multiple orthogonal cellular assays (trafficking, Golgi, autophagy) and in vivo neuropathology, consistent mechanistic picture\",\n      \"pmids\": [\"30930081\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"Spatacsin (SPG11) promotes the degradation of AP5Z1 at lysosomes, thereby regulating the relative amounts of spastizin and AP5Z1 at the lysosomal surface; AP5Z1 interacts with the retrograde motor dynein/dynactin subunit p150Glued, while spastizin interacts with anterograde motor KIF13A; together they control tubular lysosome formation and the directionality of lysosome trafficking in neurons.\",\n      \"method\": \"Co-immunoprecipitation of AP5Z1 with p150Glued and spastizin with KIF13A; protein degradation assays in mouse brain extracts and mouse embryonic fibroblasts; spatacsin knockdown/rescue experiments; live imaging of tubular lysosomes in polarized cortical neurons\",\n      \"journal\": \"PLoS biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal Co-IP for motor interactions, functional degradation assays, live-imaging in neurons, multiple orthogonal methods in one study\",\n      \"pmids\": [\"37871017\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"Disruption of Ap5z1 (AP5Z1 ζ-subunit) in mouse BMDMs sensitizes the non-canonical inflammasome, resulting in a stronger inflammatory response; mass spectrometry of activated BMDMs from Spg11 KO mice reveals massive downregulation of AP5 subunits including AP5Z1, linking the AP5 complex to non-canonical inflammasome regulation in innate immune cells.\",\n      \"method\": \"Ap5z1 knockout mouse; inflammasome activation assays in primary microglia and BMDMs; mass spectrometry of activated BMDMs; in vivo LPS challenge\",\n      \"journal\": \"EBioMedicine\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — genetic KO with functional inflammasome readout and MS proteomics, single lab\",\n      \"pmids\": [\"41138668\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"AP5Z1 promotes ubiquitination and degradation of PTEN by recruiting TRIM21 (an E3 ubiquitin ligase), thereby activating the PI3K/Akt/mTOR pathway and modulating autophagy and apoptosis in hepatocellular carcinoma cells.\",\n      \"method\": \"Co-immunoprecipitation and mass spectrometry identifying PTEN and TRIM21 as AP5Z1 partners; Western blot for PTEN ubiquitination; cell proliferation, apoptosis (flow cytometry), and autophagy assays; animal model experiments\",\n      \"journal\": \"Journal of translational medicine\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — Co-IP plus MS plus functional pathway assays in vitro and in vivo, single lab\",\n      \"pmids\": [\"40394639\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"AP5Z1 encodes the ζ subunit of the adaptor protein complex 5 (AP-5), which physically interacts with SPG11 (spatacsin) and SPG15 (spastizin) to form a complex required for late endosome-to-trans-Golgi trafficking, lysosomal recycling from autolysosomes, and autophagic flux; spatacsin promotes AP5Z1 degradation to balance retrograde (AP5Z1–dynein/dynactin) versus anterograde (spastizin–KIF13A) lysosome motility, and AP5Z1 loss blocks autophagy leading to corticospinal axon degeneration; additionally, AP5Z1 promotes PTEN ubiquitination via TRIM21 to activate PI3K/Akt/mTOR signaling and modulate autophagy, and its disruption sensitizes the non-canonical inflammasome in innate immune cells.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"AP5Z1 encodes the ζ subunit of the adaptor protein complex 5 (AP-5), which physically associates with SPG11 (spatacsin) and SPG15 (spastizin) to govern endolysosomal membrane traffic and autophagic flux [#0, #2]. AP-5 mediates retrograde trafficking from late endosomes to the trans-Golgi network and the recycling of lysosomes from autolysosomes; loss of AP5Z1 produces structural Golgi defects, impaired autophagic flux, accumulation of intracellular storage and autofluorescent material, and age-dependent degeneration of corticospinal axons [#1, #2]. Lysosome trafficking directionality is set by competition between AP5Z1, which binds the retrograde dynein/dynactin subunit p150Glued, and spastizin, which binds the anterograde motor KIF13A, with spatacsin promoting lysosomal degradation of AP5Z1 to balance the two pools [#3]. Beyond its trafficking role, AP5Z1 recruits the E3 ligase TRIM21 to drive PTEN ubiquitination and activate PI3K/Akt/mTOR signaling in hepatocellular carcinoma cells [#5], and its disruption sensitizes the non-canonical inflammasome in innate immune cells [#4]. AP5Z1 knockdown also reduces homologous-recombination double-strand break repair and sensitizes cells to DNA-damaging agents [#0].\",\n  \"teleology\": [\n    {\n      \"year\": 2010,\n      \"claim\": \"Established that AP5Z1 is not an isolated protein but a stable partner of SPG11 and SPG15, defining a novel complex and linking it to a DNA double-strand break repair phenotype.\",\n      \"evidence\": \"Genome-scale esiRNA HR-DSBR screen plus co-IP/pulldown with SPG11 and SPG15 and drug-sensitivity assay in mutant cells\",\n      \"pmids\": [\"20613862\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Mechanism connecting the complex to HR-DSBR not resolved\", \"Helicase activity asserted but not biochemically demonstrated\", \"Subunit stoichiometry and architecture undefined\"]\n    },\n    {\n      \"year\": 2016,\n      \"claim\": \"Showed that complete loss of AP5Z1 in patient cells causes lysosomal storage pathology, establishing a requirement for AP5Z1 in lysosomal homeostasis.\",\n      \"evidence\": \"Western blot, PAS staining, autofluorescence, and electron microscopy of fibroblasts from patients with biallelic AP5Z1 mutations\",\n      \"pmids\": [\"27606357\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Molecular trafficking step responsible for storage not identified\", \"Causal chain from storage to neurodegeneration unestablished\"]\n    },\n    {\n      \"year\": 2019,\n      \"claim\": \"Defined the trafficking step AP-5 acts on—late endosome-to-TGN transport and lysosome recycling from autolysosomes—and linked its failure to autophagy block and corticospinal axon degeneration.\",\n      \"evidence\": \"AP5Z1 knockout mouse with fibroblast trafficking and autophagic-flux assays, Golgi morphology analysis, and in vivo neuropathology\",\n      \"pmids\": [\"30930081\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Direct cargo molecules of AP-5 not enumerated\", \"How autophagy block translates specifically to corticospinal vulnerability unresolved\"]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Resolved how AP5Z1 levels and lysosome motility are controlled, showing spatacsin-driven degradation balances AP5Z1-dynein retrograde transport against spastizin-KIF13A anterograde transport.\",\n      \"evidence\": \"Reciprocal co-IP (AP5Z1-p150Glued, spastizin-KIF13A), degradation assays in brain extracts and MEFs, spatacsin knockdown/rescue, and live imaging of tubular lysosomes in cortical neurons\",\n      \"pmids\": [\"37871017\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Degradation machinery acting on AP5Z1 not identified\", \"Quantitative rules governing motor switching unknown\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Extended AP5Z1 function beyond trafficking into signaling, showing it recruits TRIM21 to ubiquitinate PTEN and activate PI3K/Akt/mTOR in liver cancer cells.\",\n      \"evidence\": \"Co-IP/MS identifying PTEN and TRIM21, PTEN ubiquitination Western blots, proliferation/apoptosis/autophagy assays, and animal models in hepatocellular carcinoma\",\n      \"pmids\": [\"40394639\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Whether this signaling role requires the AP-5 complex or is AP5Z1-independent unclear\", \"Direct versus bridged AP5Z1-TRIM21-PTEN interaction not dissected\", \"Generality beyond HCC untested\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Connected the AP-5 complex to innate immunity, showing AP5Z1 disruption sensitizes the non-canonical inflammasome and that AP5 subunits are downregulated in activated Spg11-KO macrophages.\",\n      \"evidence\": \"Ap5z1 knockout mouse, inflammasome activation assays in microglia and BMDMs, mass spectrometry of activated BMDMs, and in vivo LPS challenge\",\n      \"pmids\": [\"41138668\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Molecular mechanism linking AP-5 trafficking to inflammasome restraint unknown\", \"Relevant cargo or membrane compartment not identified\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"It remains unknown which membrane cargoes AP-5 selects and how a single complex coordinates endolysosomal trafficking, DNA repair, PI3K/Akt/mTOR signaling, and inflammasome control.\",\n      \"evidence\": \"No single study in the corpus integrates these roles or identifies direct AP-5 cargo\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct AP-5 cargo repertoire undefined\", \"Structural basis of subunit assembly unresolved\", \"Whether non-trafficking roles depend on the intact AP-5 complex untested\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0060090\", \"supporting_discovery_ids\": [2, 3]},\n      {\"term_id\": \"GO:0140096\", \"supporting_discovery_ids\": [5]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005764\", \"supporting_discovery_ids\": [1, 3]},\n      {\"term_id\": \"GO:0005794\", \"supporting_discovery_ids\": [2]},\n      {\"term_id\": \"GO:0005768\", \"supporting_discovery_ids\": [2]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-9612973\", \"supporting_discovery_ids\": [2, 5]},\n      {\"term_id\": \"R-HSA-5653656\", \"supporting_discovery_ids\": [2, 3]},\n      {\"term_id\": \"R-HSA-9609507\", \"supporting_discovery_ids\": [2, 3]},\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [5]},\n      {\"term_id\": \"R-HSA-168256\", \"supporting_discovery_ids\": [4]}\n    ],\n    \"complexes\": [\"AP-5 (adaptor protein complex 5)\"],\n    \"partners\": [\"SPG11\", \"SPG15\", \"DCTN1\", \"KIF13A\", \"TRIM21\", \"PTEN\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":5,"faith_total":5,"faith_pct":100.0}}