{"gene":"BLOC1S1","run_date":"2026-06-09T22:02:44","timeline":{"discoveries":[{"year":2004,"finding":"BLOS1 (BLOC1S1) was identified as a novel subunit of the BLOC-1 complex. Using co-immunoprecipitation and size exclusion chromatography, BLOS1 co-fractionates and co-immunoprecipitates with previously known BLOC-1 subunits (Pallidin, Muted, Cappuccino, Dysbindin). Yeast two-hybrid analyses revealed a network of binary interactions involving BLOS1 and other BLOC-1 subunits. Steady-state levels of BLOS1 are reduced in pallid mouse cells, indicating interdependence of complex subunit stability.","method":"Co-immunoprecipitation, size exclusion chromatography, yeast two-hybrid, genetic mouse model (pallid)","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal co-IP, co-fractionation, and genetic validation in multiple model systems, foundational paper replicated by multiple subsequent studies","pmids":["15102850"],"is_preprint":false},{"year":2012,"finding":"GCN5L1/BLOC1S1 functions as a component of the mitochondrial acetyltransferase program. It is mitochondrial-enriched, displays homology to a prokaryotic acetyltransferase, and counters the deacetylation activity of SIRT3. Genetic knockdown of GCN5L1 blunts global mitochondrial protein acetylation; reconstitution in intact mitochondria restores it. GCN5L1 interacts with and promotes acetylation of SIRT3 respiratory chain targets and reverses SIRT3 effects on mitochondrial protein acetylation, respiration, and bioenergetics.","method":"Genetic knockdown, mitochondrial reconstitution, in vitro acetylation assay, respiratory measurement, interaction studies","journal":"The Biochemical journal","confidence":"High","confidence_rationale":"Tier 2 / Strong — multiple orthogonal methods (knockdown, reconstitution, interaction studies, bioenergetic readout), independently replicated by many subsequent studies","pmids":["22309213"],"is_preprint":false},{"year":2013,"finding":"Genetic deletion of GCN5L1 directly increases expression and activity of TFEB (master regulator of autophagy) and concurrently induces PGC-1α (mitochondrial biogenesis co-activator), resulting in increased mitochondrial turnover. Knockdown of either TFEB or PGC-1α leads to decreased expression of the other, showing they act coordinately to maintain mitochondrial content in response to GCN5L1 modulation.","method":"Genetic knockout/knockdown, gene expression analysis, mitochondrial content assay, epistasis via dual knockdown","journal":"The Journal of biological chemistry","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — clean KO with defined phenotype and epistasis via dual knockdown, single lab","pmids":["24356961"],"is_preprint":false},{"year":2014,"finding":"BLOS1 interacts with SNX2 (retromer subunit) and TSG101 (ESCRT-I component) to mediate lysosomal trafficking of EGFR. BLOS1 knockdown delays EGFR degradation and causes accumulation of endolysosomes; this is rescued by BLOS1 overexpression. BLOS1 KO mouse embryonic fibroblasts phenocopy the knockdown.","method":"Co-immunoprecipitation, knockdown and rescue experiments, KO MEFs, EGFR trafficking assay","journal":"The Journal of biological chemistry","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — reciprocal Co-IP with two partners, KD/KO with defined trafficking phenotype and rescue, single lab","pmids":["25183008"],"is_preprint":false},{"year":2015,"finding":"BLOC1S1 mRNA is a specific, conserved RIDD (regulated IRE1-dependent mRNA decay) target. Under conditions of IRE1 hyperactivation, BLOC1S1 mRNA is specifically cleaved by IRE1 at guanine 444. This cleavage is temporally separate from XBP1 splicing and occurs after depletion of unspliced XBP1. However, expression of an uncleavable BLOC1S1 mutant or inhibition of RIDD did not affect cellular recovery from acute ER stress.","method":"qPCR, bioinformatics, cleavage-site mutagenesis, IRE1 RNase inhibitor, cancer cell lines","journal":"Molecular and cellular biology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — site-specific cleavage mapped by mutagenesis, but functional consequence of cleavage for cell viability was negative","pmids":["25870107"],"is_preprint":false},{"year":2017,"finding":"GCN5L1 promotes acetylation of mitochondrial fatty acid oxidation enzymes (LCAD, SCAD, HADHA) and pyruvate dehydrogenase in cardiac tissue in response to high-fat diet. GCN5L1 knockdown decreases acetylation of these enzymes and reduces fatty acid oxidation in H9C2 cardiac cells, indicating GCN5L1-mediated acetylation promotes FAO enzyme activity in the heart.","method":"Genetic knockdown, immunoprecipitation-based acetylation assay, enzymatic activity measurement, fatty acid oxidation assay, mouse HFD model","journal":"American journal of physiology. Heart and circulatory physiology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — KD with acetylation and enzymatic activity readouts in cell and mouse model, single lab","pmids":["28526709"],"is_preprint":false},{"year":2017,"finding":"TDH (responsible for mitochondrial acetyl-CoA production in mESCs) and GCN5L1 cooperate to acetylate Lys501 of KBP, enabling its recognition and degradation by the E3 ligase Fbxo15. This pathway limits mitochondrial biogenesis in mouse embryonic stem cells; defects in KBP degradation cause unscheduled increase in mitochondrial biogenesis and enhanced respiration.","method":"Co-IP, acetylation mapping, genetic epistasis (Fbxo15 KO, Kif1Bα silencing), mESC differentiation assays","journal":"Nature cell biology","confidence":"High","confidence_rationale":"Tier 1–2 / Strong — specific acetylation site identified, genetic epistasis established, multiple orthogonal methods across multiple labs","pmids":["28319092"],"is_preprint":false},{"year":2017,"finding":"Hepatic GCN5L1 ablation reduces fasting glucose and blunts gluconeogenesis. Mechanistically, GCN5L1 loss reduces FoxO1 protein levels via proteasome-dependent degradation and via ROS-mediated ERK1/2 phosphorylation. ERK inhibition restores FoxO1, gluconeogenic enzyme expression, and glucose production. Reconstitution of mitochondrial-targeted GCN5L1 blunts mitochondrial ROS and ERK activation, and restores FoxO1 and gluconeogenesis, establishing GCN5L1 as a regulator of mitochondrial ROS–ERK–FoxO1 retrograde signaling.","method":"Liver-specific knockout, pharmacological ERK inhibition, mitochondrial-targeted GCN5L1 reconstitution, ROS measurement, proteasome inhibition","journal":"Nature communications","confidence":"High","confidence_rationale":"Tier 2 / Strong — liver-specific KO, reconstitution, pharmacological and genetic epistasis, multiple orthogonal methods in single study with clear mechanistic pathway","pmids":["28900165"],"is_preprint":false},{"year":2018,"finding":"GCN5L1 interacts with the α-tubulin acetyltransferase αTAT1 and with RanBP2. GCN5L1-mediated α-tubulin acetylation in hepatocytes is αTAT1-dependent. RanBP2 possesses a tubulin-binding domain that recruits GCN5L1 to α-tubulin. Genetic silencing of RanBP2 phenocopies GCN5L1 depletion by reducing α-tubulin acetylation. GCN5L1 depletion promotes perinuclear lysosome accumulation, and HDAC inhibition partially restores lysosomal positioning.","method":"Co-immunoprecipitation, genetic knockdown, α-tubulin acetylation assay, lysosome positioning assay, HDAC inhibitor","journal":"Journal of cell science","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — Co-IP with two partners, KD phenocopy, functional rescue, single lab","pmids":["30333138"],"is_preprint":false},{"year":2018,"finding":"GCN5L1 promotes acetylation of HADHA (mitochondrial trifunctional protein subunit α) in the liver, specifically at K350, K383, and K406. Transgenic GCN5L1 overexpression in mouse liver increases HADHA acetylation and GCN5L1/SIRT3 co-regulated sites were mapped by proteomics. Stable GCN5L1 knockdown in HepG2 cells reduced HADHA acetylation and increased FAO enzyme activities. Liver-specific GCN5L1 KO mice were protected from HFD-induced hepatic lipid accumulation.","method":"Transgenic overexpression, proteomic acetylation mapping, stable KD, liver-specific KO mice, enzymatic activity assay","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1–2 / Strong — specific acetylation sites identified by proteomics, orthogonal KD/KO and OE models, enzymatic activity readout, single lab with multiple methods","pmids":["30323061"],"is_preprint":false},{"year":2019,"finding":"Degradation of Blos1 mRNA by IRE1 leads to repositioning of late endosomes/lysosomes to the microtubule-organizing center (MTOC) in response to ER stress in mouse cells. Overriding Blos1 degradation (expressing uncleavable Blos1) leads to ER stress sensitivity and accumulation of ubiquitinated protein aggregates; efficient degradation of these aggregates requires independent trafficking to the cell center and ESCRT-mediated microautophagy. Thus Blos1 downregulation by IRE1 promotes LE-mediated microautophagy and protects cells from aggregate toxicity.","method":"IRE1-mediated mRNA degradation, overexpression of uncleavable mutant, live imaging of lysosome positioning, ubiquitinated aggregate detection, ESCRT loss-of-function","journal":"The Journal of cell biology","confidence":"High","confidence_rationale":"Tier 2 / Strong — genetic rescue with uncleavable mutant, multiple pathway components tested, two orthogonal readouts (lysosome position + aggregate degradation), replicated in follow-up study (PMID:36044348)","pmids":["30787040"],"is_preprint":false},{"year":2019,"finding":"GCN5L1 directly binds the mTORC2 component Rictor. Loss of GCN5L1 in cardiomyocytes reduces Rictor acetylation, impairs Akt phosphorylation, elevates mitochondrial ROS, and reduces cell viability in response to hypoxia-reoxygenation. Restoring Rictor acetylation in GCN5L1-depleted cells reduces mitochondrial ROS and increases cell survival.","method":"Co-immunoprecipitation, genetic knockdown, Rictor acetylation assay, Akt signaling assay, hypoxia-reoxygenation cell survival assay","journal":"The Biochemical journal","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — Co-IP binding, acetylation rescue, functional cell viability readout, single lab","pmids":["31138772"],"is_preprint":false},{"year":2020,"finding":"BLOS1 interacts with kinesin-3 motor KIF13A and acts as a new adaptor for kinesin-2 motor KIF3 to coordinate kinesin-3 and kinesin-2 during long-range anterograde transport of recycling endosomes (REs) to the plasma membrane along microtubules. Loss of BLOS1 in hepatocyte-specific KO mice reduces membrane LDLR and impairs LDL clearance from plasma.","method":"Co-immunoprecipitation, hepatocyte-specific KO mice, LDLR trafficking assay, plasma LDL measurement, live imaging","journal":"eLife","confidence":"High","confidence_rationale":"Tier 2 / Strong — Co-IP of two kinesin partners, in vivo KO with defined trafficking and metabolic phenotype, multiple orthogonal methods","pmids":["33179593"],"is_preprint":false},{"year":2021,"finding":"BLOC1S1/GCN5L1 is required for autophagic lysosome reformation (ALR). In liver-specific bloc1s1 KO hepatocytes, nutrient deprivation fails to initiate ALR due to blunted lysosomal tubulation. BLOC1S1 interacts with the ARL8B–KIF5B complex to recruit KIF5B to autolysosomes and interacts with the actin nucleation-promoting factor WHAMM. Genetic reintroduction of BLOC1S1 rescues lysosomal tubulation, but not when KIF5B is concurrently depleted, establishing epistasis. MTORC1 inhibition also abolishes BLOC1S1 reconstitution-mediated rescue of tubulation.","method":"Liver-specific KO, genetic reconstitution, Co-immunoprecipitation (ARL8B, KIF5B, WHAMM), concurrent KIF5B depletion (epistasis), MTORC1 inhibition, live imaging of lysosomal tubulation","journal":"Autophagy","confidence":"High","confidence_rationale":"Tier 2 / Strong — KO with defined phenotype, genetic reconstitution rescue, epistasis by concurrent KIF5B depletion, multiple binding partners identified by Co-IP","pmids":["33629936"],"is_preprint":false},{"year":2012,"finding":"BLOS1 interacts with KXD1, a novel 20 kDa coiled-coil protein, as confirmed by in vitro binding assays. In Kxd1 knockout mice, BLOS1 protein levels are significantly reduced, and mild defects in melanosomes and platelet dense granules (lysosome-related organelles) are observed, mimicking a mild form of Hermansky-Pudlak syndrome.","method":"Naïve Bayesian analysis, in vitro binding assay, Kxd1 KO mice, ultrastructural analysis of LROs","journal":"Traffic (Copenhagen, Denmark)","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — in vitro binding confirmed, KO mice with defined LRO phenotype, single lab","pmids":["22554196"],"is_preprint":false},{"year":2022,"finding":"GCN5L1 promotes acetylation and inactivation of glutaminase isoforms GLS1 and GLS2 in the liver and increases enzyme oligomerization. GCN5L1 depletion in HCC cells promotes mTORC1 activation and cell proliferation; GCN5L1 levels inversely correlate with mTORC1 activity and glutaminase activity in human HCC tumors.","method":"Genetic KO, hepatocyte-specific KO mice, GLS1/2 acetylation and activity assay, orthotopic tumor assay, mTORC1 signaling analysis","journal":"Clinical and translational medicine","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — enzymatic activity assay + acetylation measurement + in vivo KO, single lab","pmids":["35538890"],"is_preprint":false},{"year":2022,"finding":"GCN5L1 (BLOC1S1) acetylates TFAM at K76. This acetylation inhibits TFAM binding to TOM70, thereby reducing TFAM import into mitochondria and impairing mitochondrial biogenesis. In AKI, GCN5L1 is upregulated, leading to hyperacetylation of TFAM at K76. Renal tubule-specific GCN5L1 knockdown attenuates AKI-induced mitochondrial impairment.","method":"Acetylated proteomics, Duolink proximity ligation assay, Co-immunoprecipitation, site-specific acetylation mapping, genetic KD in vivo","journal":"Journal of translational medicine","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — acetylation site mapped by proteomics, protein–protein interaction confirmed by PLA and Co-IP, in vivo KD, single lab","pmids":["36474281"],"is_preprint":false},{"year":2022,"finding":"Brucella activates RIDD (regulated IRE1-dependent decay) of Bloc1s1 mRNA to subvert innate immune defense. Inactivation of Bloc1s1 impairs BORC assembly, causing perinuclear trafficking of Brucella-containing vacuoles and enhanced susceptibility. The RIDD-resistant Bloc1s1 variant maintains BORC integrity and promotes centrifugal lysosome trafficking, resulting in lysosomal destruction of Brucella. Coronavirus MHV also exploits the RIDD–BLOS1 axis to promote replication.","method":"RIDD-deficient cell lines, RIDD-incompetent IRE1α knock-in mice, Bloc1s1 KO, BORC assembly assay, lysosome trafficking imaging, infection susceptibility assay","journal":"eLife","confidence":"High","confidence_rationale":"Tier 2 / Strong — multiple genetic models (RIDD-deficient cells and mice, KO cells), BORC assembly readout, functional infection assay, validated in two independent pathogens","pmids":["35587649"],"is_preprint":false},{"year":2022,"finding":"BLOC1S1 depletion in hepatocytes increases lysosomal content, lysosomal lipid uptake, and lipolysis independently of macro- and chaperone-mediated lipophagy but dependent on total lysosome content. Genetic induction of lysosomal biogenesis in transformed hepatocytes replicates depletion of intracellular lipid stores.","method":"Liver-specific KO mice, iPSC-derived hepatocyte-like cells (HLCs), lysosomal enzyme activity assay, lipid staining, lysosomal content measurement","journal":"Biochemical and biophysical research communications","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — KO mouse model and human iPSC-derived HLCs, multiple lipid and lysosomal readouts, single lab","pmids":["36535215"],"is_preprint":false},{"year":2022,"finding":"IRE1-mediated degradation of Blos1 mRNA enhances ESCRT-dependent endosomal microautophagy of mutant Huntingtin (mHTT), reducing accumulation of mHTT aggregates. Overriding Blos1 degradation causes excessive mHTT aggregate accumulation in cultured cells and primary neurons. Before large aggregates form, mHTT is degraded via ESCRT-dependent, macroautophagy-independent microautophagy, and this pathway is enhanced by Blos1 degradation.","method":"Uncleavable Blos1 mutant overexpression, ESCRT loss-of-function, primary neuron culture, mHTT aggregate quantification","journal":"Molecular biology of the cell","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — genetic rescue with uncleavable mutant, ESCRT epistasis, validated in primary neurons, single lab replicating prior findings","pmids":["36044348"],"is_preprint":false},{"year":2022,"finding":"GCN5L1 directly binds GPD2 (glycerol phosphate dehydrogenase 2, a key component of the mitochondrial glycerol phosphate shuttle) and modulates its activity. GCN5L1 deletion dramatically inhibits glucose production from glycerol and lactate due to increased cytosolic redox state, linked to altered GPD2 activity.","method":"Co-immunoprecipitation, genetic deletion, glucose production assay, cytosolic redox measurement, GPD2 activity assay","journal":"Biochemical and biophysical research communications","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — direct binding demonstrated by Co-IP, enzymatic activity and metabolic readouts, single lab","pmids":["35802941"],"is_preprint":false},{"year":2024,"finding":"GCN5L1 promotes Drp1 acetylation to enhance mitochondrial fission in ischemic neuronal cells. Ischemia/hypoxia induces CDK5 upregulation which activates AMPK, facilitating GCN5L1–Drp1 interaction and subsequent Drp1 acetylation; this promotes mitochondrial fission and neuronal apoptosis. GCN5L1 knockdown reduces Drp1 acetylation and mitochondrial fission; AMPK inhibition also blocks Drp1 acetylation. GCN5L1 overexpression enhances Drp1 acetylation and fission.","method":"Co-immunoprecipitation, genetic KD/OE, AMPK inhibition, CDK5 pathway analysis, mitochondrial morphology assay, dMCAO mouse model","journal":"Molecular medicine (Cambridge, Mass.)","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — Co-IP, KD/OE with acetylation and morphological readouts, pharmacological epistasis, in vivo validation, single lab","pmids":["39390372"],"is_preprint":false},{"year":2023,"finding":"GCN5L1 is present in both mitochondria and lamellar bodies (LBs) in alveolar epithelial cells. Knockout of GCN5L1 results in smaller, accumulated LB-like organelles indicating both biogenesis and trafficking defects. Reconstruction of mitochondrial GCN5L1 rescues organelle morphology but not the trafficking defect, indicating distinct roles for mitochondrial vs. non-mitochondrial GCN5L1. Loss of GCN5L1 also activates the ROS-Erk-Foxo1-Cebpα axis to downregulate surfactant-related genes.","method":"CRISPR KO, lentiviral reconstitution (mitochondrial-targeted), TEM, immunofluorescence, RNA-seq, ELISA, lipid measurement","journal":"Cellular & molecular biology letters","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — CRISPR KO with targeted reconstitution, multiple cellular readouts, single lab","pmids":["37936104"],"is_preprint":false},{"year":2024,"finding":"GCN5L1 mediates acetylation of Rictor in cardiomyocytes, preventing its proteasomal degradation under hypoxic stress. GCN5L1 knockdown reduces Rictor acetylation and protein levels after hypoxia; GCN5L1 overexpression blocks hypoxia-induced Rictor loss. This protects cytoprotective Akt/mTORC2 signaling. Rictor degradation under hypoxia is proteasome-mediated and antagonized by increased acetylation.","method":"Co-immunoprecipitation, knockdown/overexpression, Rictor acetylation assay, proteasome inhibition, Akt/mTORC2 signaling measurement","journal":"Cellular signalling","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — direct binding, acetylation-dependent stability established by OE/KD and proteasome inhibition, single lab","pmids":["38281616"],"is_preprint":false},{"year":2025,"finding":"GCN5L1 coordinates with YME1L protease and the MICOS component MIC13 to remodel mitochondrial cristae in white adipocytes. GCN5L1 protein interacts with MIC13 and YME1L in the mitochondrial intermembrane space; its accumulation during high-fat diet feeding facilitates MIC13/MICOS degradation and cristae disassembly, reducing OXPHOS complex stability and enhancing adipocyte expansion. White adipose-specific GCN5L1 KO increases cristae content, stabilizes OXPHOS complexes, and resists obesity.","method":"Protein interactome analysis, Co-IP, adipose-specific KO mice, electron microscopy for cristae analysis, OXPHOS complex activity assay","journal":"Cell reports","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — interactome Co-IP, tissue-specific KO, structural (EM) and biochemical readouts, single lab","pmids":["40338741"],"is_preprint":false},{"year":2025,"finding":"BLOC1S1/GCN5L1 is significantly upregulated in ALS patient-derived motor neurons, postmortem motor cortices, and spinal cords of ALS mouse models. BLOC1S1 depletion (via splice-switching antisense oligonucleotides inducing NMD) rescues mitochondrial respiration and ALS-relevant cellular deficits in iPSC-derived motor neurons from diverse genetic backgrounds, and extends survival in an ALS mouse model.","method":"iPSC-derived motor neurons, splice-switching ASO, mitochondrial respiration assay, ALS mouse model survival, postmortem patient tissue","journal":"Molecular therapy","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — KD with defined mitochondrial and in vivo phenotype, multiple genetic backgrounds, single lab","pmids":["41383013"],"is_preprint":false},{"year":2026,"finding":"BLOC1S1 KO impairs anterograde transport of lysosomes and autophagy in both non-neuronal cells and iPSC-derived neurons. Most pathogenic BLOC1S1 variants exhibit reduced expression, decreased assembly with BORC/BLOC-1 subunits, and/or impaired rescue of lysosome transport and autophagy in BLOC1S1-KO cells. Evidence indicates loss of BLOC1S1 leads to more pronounced deficits in BORC function than in BLOC-1 function.","method":"BLOC1S1 KO cell lines, iPSC-derived neurons, transfection rescue experiments, lysosome transport assay, autophagy assay, BORC/BLOC-1 assembly assay, melanocytic pigmentation assay","journal":"American journal of human genetics","confidence":"High","confidence_rationale":"Tier 2 / Strong — KO rescue experiments with multiple variants, multiple cell types including iPSC-neurons, multiple orthogonal readouts (lysosome transport, autophagy, pigmentation, complex assembly)","pmids":["41887224"],"is_preprint":false},{"year":2026,"finding":"GCN5L1 undergoes stimulus-dependent translocation from mitochondria to the cytoplasm during lipid overload and high-fat diet feeding. Cytoplasmic GCN5L1 binds PPARγ and promotes its acetylation at K289, protecting PPARγ from ubiquitination-mediated proteasomal degradation. PPARγ-K289 mutation reduces ubiquitination of PPARγ and exacerbates liver steatosis in mice, establishing GCN5L1 as a mitochondrial retrograde signal controlling hepatic lipid synthesis via PPARγ stabilization.","method":"Subcellular fractionation, Co-immunoprecipitation, acetylation site mapping (K289), PPARγ-K289 mutant mice, transcriptome and proteome analysis, ubiquitination assay","journal":"JCI insight","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — direct binding confirmed, specific acetylation site identified, in vivo KI mutant, single lab","pmids":["41574605"],"is_preprint":false},{"year":2021,"finding":"GCN5L1 does not possess intrinsic acetyltransferase activity (as shown by functional-domain sequence alignment and experimental studies), yet supports protein acetylation in mitochondria and cytosol by acting as a subunit of numerous multiprotein complexes.","method":"Functional domain analysis, experimental studies (cited in review)","journal":"Biochimica et biophysica acta. Gene regulatory mechanisms","confidence":"Low","confidence_rationale":"Tier 4 / Weak — review summarizing prior experimental data, no new primary experiments described","pmids":["32599084"],"is_preprint":false},{"year":2024,"finding":"GCN5L1 deficiency in HCC cells increases sorafenib sensitivity by downregulating the mitochondrial iron transporter CISD1, leading to mitochondrial iron accumulation, increased cellular and lipid ROS, and ferroptosis. GCN5L1 modulates mitochondrial iron homeostasis via regulation of CISD1 expression.","method":"CRISPR KO, sorafenib sensitivity assay, CISD1 expression analysis, ROS measurement, lipid peroxidation assay, in vivo orthotopic tumor model","journal":"Journal of translational medicine","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — CRISPR KO with defined mechanistic pathway (CISD1), in vitro and in vivo validation, single lab","pmids":["38918793"],"is_preprint":false},{"year":2025,"finding":"BLOC1S1 sequesters TDP-43 in the cytoplasm, inhibiting its nuclear translocation-dependent ATG7 mRNA stabilization and autophagy induction. Co-immunoprecipitation confirmed direct interaction between BLOC1S1 and TDP-43. BLOC1S1 overexpression attenuates autophagy and reduces autolysosome formation in goat spermatogonial stem cells challenged with Brucella LPS.","method":"Co-immunoprecipitation, subcellular localization (immunofluorescence), BLOC1S1 overexpression, TEM, LC3B-II/I ratio, RNA-seq and proteomics","journal":"Advanced science","confidence":"Low","confidence_rationale":"Tier 3 / Weak — Co-IP and localization in single model cell type (goat SSCs), single lab, partial mechanistic follow-up","pmids":["40936170"],"is_preprint":false}],"current_model":"BLOC1S1/GCN5L1/BLOS1 is a multifunctional scaffold protein that exists as both mitochondrial and cytosolic isoforms and acts as a shared subunit of the BLOC-1 and BORC multiprotein complexes: in the mitochondria it promotes protein acetylation (of respiratory chain proteins, FAO enzymes, Drp1, TFAM, Rictor, glutaminase, and PDH) to regulate metabolism and dynamics, while in the endolysosomal compartment it coordinates BORC-dependent anterograde lysosome transport (via ARL8B–KIF5B), autophagic lysosome reformation (via WHAMM and KIF5B), and endosomal recycling (via KIF13A/KIF3); its mRNA is also a specific IRE1 RIDD target, whose degradation repositions lysosomes to the MTOC to promote microautophagy of protein aggregates under ER stress."},"narrative":{"mechanistic_narrative":"BLOC1S1 (BLOS1/GCN5L1) is a small multifunctional scaffold that operates in two distinct cellular arenas: as a shared subunit of the BLOC-1 and BORC complexes governing endolysosomal organelle biogenesis and transport, and as a mitochondrial regulator of protein acetylation and metabolism [PMID:15102850, PMID:22309213, PMID:41887224]. It was first defined as a BLOC-1 subunit whose stability is interdependent with the other subunits (Pallidin, Muted, Cappuccino, Dysbindin) and the accessory partner KXD1, with loss producing lysosome-related organelle defects reminiscent of Hermansky-Pudlak syndrome [PMID:15102850, PMID:22554196]. In the endolysosomal system it drives BORC-dependent anterograde lysosome positioning and autophagy, with most pathogenic BLOC1S1 variants showing reduced complex assembly and impaired rescue of lysosome transport, a phenotype more severe for BORC than for BLOC-1 function [PMID:41887224]. It coordinates microtubule motors for organelle movement, acting as an adaptor linking kinesin-3 (KIF13A) and kinesin-2 (KIF3) for recycling-endosome transport that delivers LDLR to the plasma membrane, and recruiting the ARL8B-KIF5B machinery together with the actin nucleator WHAMM to enable mTORC1-dependent autophagic lysosome reformation [PMID:33179593, PMID:33629936]. It also supports lysosomal degradative trafficking of EGFR via SNX2 and TSG101 [PMID:25183008]. Although it lacks intrinsic enzymatic activity, mitochondrial BLOC1S1/GCN5L1 promotes acetylation of numerous targets — respiratory chain proteins counteracting SIRT3, fatty-acid-oxidation enzymes (HADHA, LCAD, SCAD) and PDH, the fission factor Drp1, TFAM, Rictor, and glutaminase — thereby tuning oxidative metabolism, mitochondrial biogenesis and turnover, cristae remodeling, and retrograde ROS-ERK-FoxO1 signaling [PMID:22309213, PMID:28526709, PMID:30323061, PMID:31138772, PMID:36474281, PMID:39390372, PMID:40338741]. Its mRNA is a specific RIDD substrate of IRE1, and IRE1-driven Blos1 degradation repositions lysosomes to the MTOC to promote ESCRT-dependent microautophagy of protein aggregates and to control intracellular pathogen trafficking [PMID:25870107, PMID:30787040, PMID:35587649, PMID:36044348]. Loss-of-function or dysregulation links BLOC1S1 to disease: pathogenic variants cause a lysosome-transport disorder, and its upregulation contributes to mitochondrial deficits in ALS [PMID:41383013, PMID:41887224].","teleology":[{"year":2004,"claim":"Established BLOC1S1 as a bona fide structural subunit of the BLOC-1 complex, defining its founding role in lysosome-related organelle biogenesis.","evidence":"Co-IP, size exclusion chromatography, yeast two-hybrid, and pallid mouse genetics","pmids":["15102850"],"confidence":"High","gaps":["Did not resolve BLOC-1 architecture at residue level","Did not address non-BLOC-1 functions"]},{"year":2012,"claim":"Identified BLOC1S1/GCN5L1 as a mitochondrial-enriched regulator that supports protein acetylation antagonizing SIRT3, opening an entirely separate functional axis from BLOC-1.","evidence":"Knockdown, mitochondrial reconstitution, in vitro acetylation and respiration assays","pmids":["22309213"],"confidence":"High","gaps":["Whether GCN5L1 itself catalyzes acetylation or scaffolds an acetyltransferase was unresolved","Specific substrate residues not mapped"]},{"year":2012,"claim":"Connected BLOC1S1 to the accessory factor KXD1 and to lysosome-related organelle integrity, reinforcing subunit-interdependent stability.","evidence":"In vitro binding assay and Kxd1 KO mice with LRO ultrastructural defects","pmids":["22554196"],"confidence":"Medium","gaps":["Mechanism by which KXD1 stabilizes BLOS1 unclear","Mild phenotype leaves redundancy unaddressed"]},{"year":2013,"claim":"Showed GCN5L1 negatively regulates mitochondrial turnover by restraining a coordinated TFEB/PGC-1α program, linking it to autophagy and biogenesis balance.","evidence":"KO/knockdown with gene expression and mitochondrial content assays, dual-knockdown epistasis","pmids":["24356961"],"confidence":"Medium","gaps":["Direct molecular target connecting GCN5L1 to TFEB not identified","Single lab"]},{"year":2014,"claim":"Demonstrated a BLOC1S1 role in endosomal sorting by linking it to SNX2 and TSG101 to drive lysosomal degradation of EGFR.","evidence":"Reciprocal Co-IP, KD/KO MEFs and rescue, EGFR trafficking assay","pmids":["25183008"],"confidence":"Medium","gaps":["Whether this reflects BLOC-1, BORC, or retromer-specific activity unclear","Single lab"]},{"year":2015,"claim":"Defined BLOC1S1 mRNA as a specific, conserved RIDD target cleaved by IRE1 at a mapped site, establishing post-transcriptional control under ER stress.","evidence":"qPCR, bioinformatics, cleavage-site mutagenesis, IRE1 RNase inhibitor in cancer cells","pmids":["25870107"],"confidence":"Medium","gaps":["Functional consequence for acute ER-stress recovery was negative","Downstream effect of Blos1 loss not yet defined here"]},{"year":2017,"claim":"Extended GCN5L1's metabolic reach by showing it promotes acetylation of FAO enzymes and PDH and a TDH-coupled acetylation of KBP, regulating cardiac fatty acid oxidation and stem-cell mitochondrial biogenesis.","evidence":"Knockdown with acetylation/activity assays, HFD mice; acetylation-site mapping and Fbxo15/Kif1B genetic epistasis in mESCs","pmids":["28526709","28319092"],"confidence":"High","gaps":["Mechanism of substrate selection by GCN5L1 unresolved","Tissue-specificity of acetylation targets unclear"]},{"year":2017,"claim":"Established GCN5L1 as a node in mitochondrial retrograde signaling controlling hepatic gluconeogenesis via ROS-ERK-FoxO1.","evidence":"Liver-specific KO, ERK inhibition, mitochondrial-targeted reconstitution, ROS and proteasome assays","pmids":["28900165"],"confidence":"High","gaps":["Direct mitochondrial acetylation substrate triggering ROS not pinpointed","Single study"]},{"year":2018,"claim":"Linked GCN5L1 to cytoskeletal acetylation and lysosome positioning through αTAT1 and RanBP2, bridging its mitochondrial and trafficking roles.","evidence":"Co-IP, knockdown phenocopy, α-tubulin acetylation and lysosome positioning assays, HDAC inhibitor","pmids":["30333138"],"confidence":"Medium","gaps":["Whether GCN5L1 directly acetylates tubulin vs. recruits αTAT1 unclear","Single lab"]},{"year":2018,"claim":"Mapped specific HADHA acetylation sites regulated by GCN5L1/SIRT3, tying GCN5L1 to hepatic lipid handling and protection from diet-induced steatosis.","evidence":"Transgenic OE, proteomic site mapping, stable KD, liver-specific KO, enzymatic assays","pmids":["30323061"],"confidence":"High","gaps":["In vivo stoichiometry of site occupancy unclear","Single lab"]},{"year":2019,"claim":"Resolved the functional purpose of IRE1-mediated Blos1 decay: lysosome repositioning to the MTOC enables ESCRT-dependent microautophagy of ubiquitinated aggregates under ER stress.","evidence":"Uncleavable Blos1 mutant rescue, live imaging, ESCRT loss-of-function, aggregate detection","pmids":["30787040"],"confidence":"High","gaps":["How reduced BLOS1 mechanistically shifts lysosome polarity not fully defined","Link to BORC disassembly not yet shown here"]},{"year":2019,"claim":"Showed GCN5L1 binds and acetylates Rictor to sustain mTORC2/Akt signaling and limit mitochondrial ROS in cardiomyocyte stress.","evidence":"Co-IP, knockdown, Rictor acetylation rescue, hypoxia-reoxygenation survival assay","pmids":["31138772"],"confidence":"Medium","gaps":["Acetylation site on Rictor not mapped in this study","Single lab"]},{"year":2020,"claim":"Defined BLOS1 as a dual kinesin adaptor (KIF13A and KIF3) coordinating long-range anterograde recycling-endosome transport that controls LDLR surface delivery and plasma LDL clearance.","evidence":"Co-IP, hepatocyte-specific KO mice, LDLR trafficking and LDL measurement, live imaging","pmids":["33179593"],"confidence":"High","gaps":["How BLOS1 switches between motor types unclear","Relationship to BORC complex in this role not defined"]},{"year":2021,"claim":"Established BLOC1S1 as required for autophagic lysosome reformation by recruiting ARL8B-KIF5B and WHAMM to drive mTORC1-dependent lysosomal tubulation.","evidence":"Liver-specific KO, reconstitution rescue, Co-IP, concurrent KIF5B depletion epistasis, MTORC1 inhibition, live imaging","pmids":["33629936"],"confidence":"High","gaps":["Order of WHAMM actin nucleation vs. KIF5B recruitment unclear","Single lab"]},{"year":2021,"claim":"Clarified that GCN5L1 lacks intrinsic acetyltransferase activity and instead functions as a multi-complex scaffold supporting acetylation.","evidence":"Functional-domain alignment and review of prior experimental data","pmids":["32599084"],"confidence":"Low","gaps":["Review without new primary experiments","Identity of the catalytic enzyme(s) it scaffolds not established"]},{"year":2022,"claim":"Expanded the metabolic substrate repertoire (glutaminase, TFAM, GPD2) and connected GCN5L1 to mTORC1 activity, mitochondrial biogenesis, and redox-coupled gluconeogenesis.","evidence":"Hepatocyte-specific KO, acetylation/activity assays, PLA and Co-IP, glucose production and redox assays, HCC tumor models","pmids":["35538890","36474281","35802941"],"confidence":"Medium","gaps":["Whether TFAM/glutaminase acetylation is direct or scaffold-mediated unresolved","Single labs per substrate"]},{"year":2022,"claim":"Generalized the RIDD-BLOS1 axis to host-pathogen conflict, showing IRE1-driven Blos1 decay disrupts BORC assembly and lysosome positioning to either restrict or be exploited by intracellular pathogens.","evidence":"RIDD-deficient cells and IRE1α knock-in mice, Bloc1s1 KO, BORC assembly and lysosome imaging, Brucella and coronavirus infection assays","pmids":["35587649"],"confidence":"High","gaps":["How BLOS1 loss biochemically destabilizes BORC not detailed","Generalizability beyond tested pathogens unclear"]},{"year":2022,"claim":"Reinforced the aggregate-clearance role by showing Blos1 decay enhances ESCRT-dependent microautophagy of mutant Huntingtin in neurons.","evidence":"Uncleavable Blos1 mutant, ESCRT loss-of-function, primary neuron mHTT quantification","pmids":["36044348"],"confidence":"Medium","gaps":["Whether basal BLOS1 levels limit clearance in disease unclear","Single lab replicating prior work"]},{"year":2022,"claim":"Linked BLOC1S1 lysosomal control to hepatic lipid storage, with depletion raising lysosomal content and lipolysis independent of canonical lipophagy.","evidence":"Liver-specific KO mice and iPSC-derived hepatocytes with lysosomal and lipid readouts","pmids":["36535215"],"confidence":"Medium","gaps":["Mechanism coupling BLOC1S1 loss to lysosome biogenesis unclear","Single lab"]},{"year":2023,"claim":"Demonstrated functionally separable mitochondrial vs. non-mitochondrial GCN5L1 pools in alveolar cells, where mitochondrial reconstitution rescues organelle morphology but not trafficking.","evidence":"CRISPR KO, mitochondrial-targeted reconstitution, TEM, RNA-seq, lipid measurement","pmids":["37936104"],"confidence":"Medium","gaps":["Molecular basis of pool partitioning not defined","Single lab"]},{"year":2024,"claim":"Added Drp1 acetylation as a GCN5L1 output controlling mitochondrial fission and neuronal apoptosis downstream of CDK5-AMPK in ischemia.","evidence":"Co-IP, KD/OE, AMPK inhibition, mitochondrial morphology, dMCAO mouse model","pmids":["39390372"],"confidence":"Medium","gaps":["Drp1 acetylation site not mapped","Single lab"]},{"year":2024,"claim":"Showed GCN5L1 stabilizes Rictor via acetylation against proteasomal degradation under hypoxia and modulates ferroptosis sensitivity via CISD1-dependent mitochondrial iron homeostasis in HCC.","evidence":"Co-IP, KD/OE with proteasome inhibition; CRISPR KO with sorafenib sensitivity, ROS, lipid peroxidation, tumor models","pmids":["38281616","38918793"],"confidence":"Medium","gaps":["Whether CISD1 regulation is acetylation-dependent unclear","Single labs"]},{"year":2025,"claim":"Defined a cristae-remodeling role via GCN5L1 interaction with YME1L and MIC13/MICOS that degrades cristae junctions and promotes adipocyte expansion in obesity.","evidence":"Interactome Co-IP, adipose-specific KO, EM cristae analysis, OXPHOS activity assays","pmids":["40338741"],"confidence":"Medium","gaps":["Whether MIC13 degradation requires acetylation unclear","Single lab"]},{"year":2025,"claim":"Implicated GCN5L1 in stimulus-dependent mitochondria-to-cytoplasm translocation that stabilizes PPARγ by K289 acetylation, and in ALS pathology where its upregulation impairs motor-neuron mitochondria.","evidence":"Subcellular fractionation, Co-IP, K289 site mapping, PPARγ-KI mice; iPSC motor neurons, splice-switching ASO, ALS mouse survival, postmortem tissue","pmids":["41574605","41383013"],"confidence":"Medium","gaps":["Trigger and machinery for translocation not defined","Causality of GCN5L1 upregulation in human ALS unproven"]},{"year":2026,"claim":"Connected BLOC1S1 to human Mendelian disease, showing pathogenic variants impair BORC/BLOC-1 assembly and lysosome transport with BORC function more affected than BLOC-1.","evidence":"BLOC1S1-KO cells and iPSC neurons, variant rescue, lysosome transport, autophagy, pigmentation, complex-assembly assays","pmids":["41887224"],"confidence":"High","gaps":["Genotype-phenotype correlation across variants incomplete","Mechanism of differential BORC vs BLOC-1 sensitivity unclear"]},{"year":null,"claim":"It remains unresolved how a single non-catalytic scaffold partitions between mitochondrial acetylation and endolysosomal trafficking roles, and which acetyltransferase(s) GCN5L1 actually scaffolds.","evidence":"","pmids":[],"confidence":"Low","gaps":["Identity of the catalytic enzyme supported by GCN5L1 unknown","Regulation of subcellular pool partitioning undefined","Structural basis for shared BORC/BLOC-1 subunit usage not determined"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0060090","term_label":"molecular adaptor activity","supporting_discovery_ids":[12,13,0]},{"term_id":"GO:0140096","term_label":"catalytic activity, acting on a protein","supporting_discovery_ids":[1,9,16,21]},{"term_id":"GO:0005198","term_label":"structural molecule activity","supporting_discovery_ids":[0,26]}],"localization":[{"term_id":"GO:0005739","term_label":"mitochondrion","supporting_discovery_ids":[1,7,24]},{"term_id":"GO:0005829","term_label":"cytosol","supporting_discovery_ids":[27,30]},{"term_id":"GO:0005764","term_label":"lysosome","supporting_discovery_ids":[13,17,8]},{"term_id":"GO:0005768","term_label":"endosome","supporting_discovery_ids":[3,12]}],"pathway":[{"term_id":"R-HSA-5653656","term_label":"Vesicle-mediated transport","supporting_discovery_ids":[3,12,13]},{"term_id":"R-HSA-9612973","term_label":"Autophagy","supporting_discovery_ids":[13,10,19]},{"term_id":"R-HSA-1430728","term_label":"Metabolism","supporting_discovery_ids":[5,9,15]},{"term_id":"R-HSA-8953854","term_label":"Metabolism of RNA","supporting_discovery_ids":[4,10,17]},{"term_id":"R-HSA-9609507","term_label":"Protein localization","supporting_discovery_ids":[12,13,17]}],"complexes":["BLOC-1","BORC"],"partners":["KIF5B","ARL8B","WHAMM","KIF13A","KIF3","RICTOR","SNX2","KXD1"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"P78537","full_name":"Biogenesis of lysosome-related organelles complex 1 subunit 1","aliases":["GCN5-like protein 1","Protein RT14","Protein acetyltransferase BLOC1S1"],"length_aa":153,"mass_kda":17.3,"function":"Component of the BLOC-1 complex, a complex that is required for normal biogenesis of lysosome-related organelles (LRO), such as platelet dense granules and melanosomes (PubMed:17182842). In concert with the AP-3 complex, the BLOC-1 complex is required to target membrane protein cargos into vesicles assembled at cell bodies for delivery into neurites and nerve terminals (PubMed:17182842). The BLOC-1 complex, in association with SNARE proteins, is also proposed to be involved in neurite extension (PubMed:17182842). As part of the BORC complex may play a role in lysosomes movement and localization at the cell periphery (PubMed:25898167). Associated with the cytosolic face of lysosomes, the BORC complex may recruit ARL8B and couple lysosomes to microtubule plus-end-directed kinesin motor (PubMed:25898167) Acts as a protein acetyltransferase (PubMed:22309213, PubMed:38281616). Negatively regulates aerobic respiration through mitochondrial protein lysine-acetylation (PubMed:22309213). May counteract the action of the deacetylase SIRT3 by acetylating and regulating proteins of the mitochondrial respiratory chain including ATP5F1A and NDUFA9 (PubMed:22309213). Acts as a regulator of mTORC2 signaling in response to hypotoxic stress by mediating acetylation of RICTOR, thereby protecting RICTOR against ubiquitination and subsequent degradation by the proteasome (PubMed:38281616)","subcellular_location":"Mitochondrion intermembrane space; Mitochondrion matrix; Cytoplasm, cytosol; Lysosome membrane","url":"https://www.uniprot.org/uniprotkb/P78537/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/BLOC1S1","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":[{"gene":"LAMTOR2","stoichiometry":0.2}],"url":"https://opencell.sf.czbiohub.org/search/BLOC1S1","total_profiled":1310},"omim":[{"mim_id":"616601","title":"BLOC1-RELATED COMPLEX, SUBUNIT 8; BORCS8","url":"https://www.omim.org/entry/616601"},{"mim_id":"616600","title":"BLOC1-RELATED COMPLEX, SUBUNIT 7; BORCS7","url":"https://www.omim.org/entry/616600"},{"mim_id":"616599","title":"BLOC1-RELATED COMPLEX, SUBUNIT 6; BORCS6","url":"https://www.omim.org/entry/616599"},{"mim_id":"616598","title":"BLOC1-RELATED COMPLEX, SUBUNIT 5; BORCS5","url":"https://www.omim.org/entry/616598"},{"mim_id":"615178","title":"KXDL MOTIF-CONTAINING PROTEIN 1; KXD1","url":"https://www.omim.org/entry/615178"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"","locations":[],"tissue_specificity":"Low tissue specificity","tissue_distribution":"Detected in all","driving_tissues":[],"url":"https://www.proteinatlas.org/search/BLOC1S1"},"hgnc":{"alias_symbol":["BLOS1","BORCS1"],"prev_symbol":["GCN5L1"]},"alphafold":{"accession":"P78537","domains":[],"viewer_url":"https://alphafold.ebi.ac.uk/entry/P78537","model_url":"https://alphafold.ebi.ac.uk/files/AF-P78537-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-P78537-F1-predicted_aligned_error_v6.png","plddt_mean":89.0},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=BLOC1S1","jax_strain_url":"https://www.jax.org/strain/search?query=BLOC1S1"},"sequence":{"accession":"P78537","fasta_url":"https://rest.uniprot.org/uniprotkb/P78537.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/P78537/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/P78537"}},"corpus_meta":[{"pmid":"15102850","id":"PMC_15102850","title":"Identification of snapin and three novel proteins (BLOS1, BLOS2, and BLOS3/reduced pigmentation) as subunits of biogenesis of lysosome-related organelles complex-1 (BLOC-1).","date":"2004","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/15102850","citation_count":221,"is_preprint":false},{"pmid":"22309213","id":"PMC_22309213","title":"Identification of a molecular component of the mitochondrial acetyltransferase programme: a novel role for GCN5L1.","date":"2012","source":"The Biochemical journal","url":"https://pubmed.ncbi.nlm.nih.gov/22309213","citation_count":187,"is_preprint":false},{"pmid":"24356961","id":"PMC_24356961","title":"GCN5-like protein 1 (GCN5L1) controls mitochondrial content through coordinated regulation of mitochondrial biogenesis and mitophagy.","date":"2013","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/24356961","citation_count":111,"is_preprint":false},{"pmid":"28526709","id":"PMC_28526709","title":"Acetylation of mitochondrial proteins by GCN5L1 promotes enhanced fatty acid oxidation in the heart.","date":"2017","source":"American journal of physiology. 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Using co-immunoprecipitation and size exclusion chromatography, BLOS1 co-fractionates and co-immunoprecipitates with previously known BLOC-1 subunits (Pallidin, Muted, Cappuccino, Dysbindin). Yeast two-hybrid analyses revealed a network of binary interactions involving BLOS1 and other BLOC-1 subunits. Steady-state levels of BLOS1 are reduced in pallid mouse cells, indicating interdependence of complex subunit stability.\",\n      \"method\": \"Co-immunoprecipitation, size exclusion chromatography, yeast two-hybrid, genetic mouse model (pallid)\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal co-IP, co-fractionation, and genetic validation in multiple model systems, foundational paper replicated by multiple subsequent studies\",\n      \"pmids\": [\"15102850\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"GCN5L1/BLOC1S1 functions as a component of the mitochondrial acetyltransferase program. It is mitochondrial-enriched, displays homology to a prokaryotic acetyltransferase, and counters the deacetylation activity of SIRT3. Genetic knockdown of GCN5L1 blunts global mitochondrial protein acetylation; reconstitution in intact mitochondria restores it. GCN5L1 interacts with and promotes acetylation of SIRT3 respiratory chain targets and reverses SIRT3 effects on mitochondrial protein acetylation, respiration, and bioenergetics.\",\n      \"method\": \"Genetic knockdown, mitochondrial reconstitution, in vitro acetylation assay, respiratory measurement, interaction studies\",\n      \"journal\": \"The Biochemical journal\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — multiple orthogonal methods (knockdown, reconstitution, interaction studies, bioenergetic readout), independently replicated by many subsequent studies\",\n      \"pmids\": [\"22309213\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"Genetic deletion of GCN5L1 directly increases expression and activity of TFEB (master regulator of autophagy) and concurrently induces PGC-1α (mitochondrial biogenesis co-activator), resulting in increased mitochondrial turnover. Knockdown of either TFEB or PGC-1α leads to decreased expression of the other, showing they act coordinately to maintain mitochondrial content in response to GCN5L1 modulation.\",\n      \"method\": \"Genetic knockout/knockdown, gene expression analysis, mitochondrial content assay, epistasis via dual knockdown\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — clean KO with defined phenotype and epistasis via dual knockdown, single lab\",\n      \"pmids\": [\"24356961\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2014,\n      \"finding\": \"BLOS1 interacts with SNX2 (retromer subunit) and TSG101 (ESCRT-I component) to mediate lysosomal trafficking of EGFR. BLOS1 knockdown delays EGFR degradation and causes accumulation of endolysosomes; this is rescued by BLOS1 overexpression. BLOS1 KO mouse embryonic fibroblasts phenocopy the knockdown.\",\n      \"method\": \"Co-immunoprecipitation, knockdown and rescue experiments, KO MEFs, EGFR trafficking assay\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — reciprocal Co-IP with two partners, KD/KO with defined trafficking phenotype and rescue, single lab\",\n      \"pmids\": [\"25183008\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"BLOC1S1 mRNA is a specific, conserved RIDD (regulated IRE1-dependent mRNA decay) target. Under conditions of IRE1 hyperactivation, BLOC1S1 mRNA is specifically cleaved by IRE1 at guanine 444. This cleavage is temporally separate from XBP1 splicing and occurs after depletion of unspliced XBP1. However, expression of an uncleavable BLOC1S1 mutant or inhibition of RIDD did not affect cellular recovery from acute ER stress.\",\n      \"method\": \"qPCR, bioinformatics, cleavage-site mutagenesis, IRE1 RNase inhibitor, cancer cell lines\",\n      \"journal\": \"Molecular and cellular biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — site-specific cleavage mapped by mutagenesis, but functional consequence of cleavage for cell viability was negative\",\n      \"pmids\": [\"25870107\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"GCN5L1 promotes acetylation of mitochondrial fatty acid oxidation enzymes (LCAD, SCAD, HADHA) and pyruvate dehydrogenase in cardiac tissue in response to high-fat diet. GCN5L1 knockdown decreases acetylation of these enzymes and reduces fatty acid oxidation in H9C2 cardiac cells, indicating GCN5L1-mediated acetylation promotes FAO enzyme activity in the heart.\",\n      \"method\": \"Genetic knockdown, immunoprecipitation-based acetylation assay, enzymatic activity measurement, fatty acid oxidation assay, mouse HFD model\",\n      \"journal\": \"American journal of physiology. Heart and circulatory physiology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — KD with acetylation and enzymatic activity readouts in cell and mouse model, single lab\",\n      \"pmids\": [\"28526709\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"TDH (responsible for mitochondrial acetyl-CoA production in mESCs) and GCN5L1 cooperate to acetylate Lys501 of KBP, enabling its recognition and degradation by the E3 ligase Fbxo15. This pathway limits mitochondrial biogenesis in mouse embryonic stem cells; defects in KBP degradation cause unscheduled increase in mitochondrial biogenesis and enhanced respiration.\",\n      \"method\": \"Co-IP, acetylation mapping, genetic epistasis (Fbxo15 KO, Kif1Bα silencing), mESC differentiation assays\",\n      \"journal\": \"Nature cell biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1–2 / Strong — specific acetylation site identified, genetic epistasis established, multiple orthogonal methods across multiple labs\",\n      \"pmids\": [\"28319092\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2017,\n      \"finding\": \"Hepatic GCN5L1 ablation reduces fasting glucose and blunts gluconeogenesis. Mechanistically, GCN5L1 loss reduces FoxO1 protein levels via proteasome-dependent degradation and via ROS-mediated ERK1/2 phosphorylation. ERK inhibition restores FoxO1, gluconeogenic enzyme expression, and glucose production. Reconstitution of mitochondrial-targeted GCN5L1 blunts mitochondrial ROS and ERK activation, and restores FoxO1 and gluconeogenesis, establishing GCN5L1 as a regulator of mitochondrial ROS–ERK–FoxO1 retrograde signaling.\",\n      \"method\": \"Liver-specific knockout, pharmacological ERK inhibition, mitochondrial-targeted GCN5L1 reconstitution, ROS measurement, proteasome inhibition\",\n      \"journal\": \"Nature communications\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — liver-specific KO, reconstitution, pharmacological and genetic epistasis, multiple orthogonal methods in single study with clear mechanistic pathway\",\n      \"pmids\": [\"28900165\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"GCN5L1 interacts with the α-tubulin acetyltransferase αTAT1 and with RanBP2. GCN5L1-mediated α-tubulin acetylation in hepatocytes is αTAT1-dependent. RanBP2 possesses a tubulin-binding domain that recruits GCN5L1 to α-tubulin. Genetic silencing of RanBP2 phenocopies GCN5L1 depletion by reducing α-tubulin acetylation. GCN5L1 depletion promotes perinuclear lysosome accumulation, and HDAC inhibition partially restores lysosomal positioning.\",\n      \"method\": \"Co-immunoprecipitation, genetic knockdown, α-tubulin acetylation assay, lysosome positioning assay, HDAC inhibitor\",\n      \"journal\": \"Journal of cell science\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — Co-IP with two partners, KD phenocopy, functional rescue, single lab\",\n      \"pmids\": [\"30333138\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"GCN5L1 promotes acetylation of HADHA (mitochondrial trifunctional protein subunit α) in the liver, specifically at K350, K383, and K406. Transgenic GCN5L1 overexpression in mouse liver increases HADHA acetylation and GCN5L1/SIRT3 co-regulated sites were mapped by proteomics. Stable GCN5L1 knockdown in HepG2 cells reduced HADHA acetylation and increased FAO enzyme activities. Liver-specific GCN5L1 KO mice were protected from HFD-induced hepatic lipid accumulation.\",\n      \"method\": \"Transgenic overexpression, proteomic acetylation mapping, stable KD, liver-specific KO mice, enzymatic activity assay\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1–2 / Strong — specific acetylation sites identified by proteomics, orthogonal KD/KO and OE models, enzymatic activity readout, single lab with multiple methods\",\n      \"pmids\": [\"30323061\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"Degradation of Blos1 mRNA by IRE1 leads to repositioning of late endosomes/lysosomes to the microtubule-organizing center (MTOC) in response to ER stress in mouse cells. Overriding Blos1 degradation (expressing uncleavable Blos1) leads to ER stress sensitivity and accumulation of ubiquitinated protein aggregates; efficient degradation of these aggregates requires independent trafficking to the cell center and ESCRT-mediated microautophagy. Thus Blos1 downregulation by IRE1 promotes LE-mediated microautophagy and protects cells from aggregate toxicity.\",\n      \"method\": \"IRE1-mediated mRNA degradation, overexpression of uncleavable mutant, live imaging of lysosome positioning, ubiquitinated aggregate detection, ESCRT loss-of-function\",\n      \"journal\": \"The Journal of cell biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — genetic rescue with uncleavable mutant, multiple pathway components tested, two orthogonal readouts (lysosome position + aggregate degradation), replicated in follow-up study (PMID:36044348)\",\n      \"pmids\": [\"30787040\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"GCN5L1 directly binds the mTORC2 component Rictor. Loss of GCN5L1 in cardiomyocytes reduces Rictor acetylation, impairs Akt phosphorylation, elevates mitochondrial ROS, and reduces cell viability in response to hypoxia-reoxygenation. Restoring Rictor acetylation in GCN5L1-depleted cells reduces mitochondrial ROS and increases cell survival.\",\n      \"method\": \"Co-immunoprecipitation, genetic knockdown, Rictor acetylation assay, Akt signaling assay, hypoxia-reoxygenation cell survival assay\",\n      \"journal\": \"The Biochemical journal\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — Co-IP binding, acetylation rescue, functional cell viability readout, single lab\",\n      \"pmids\": [\"31138772\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"BLOS1 interacts with kinesin-3 motor KIF13A and acts as a new adaptor for kinesin-2 motor KIF3 to coordinate kinesin-3 and kinesin-2 during long-range anterograde transport of recycling endosomes (REs) to the plasma membrane along microtubules. Loss of BLOS1 in hepatocyte-specific KO mice reduces membrane LDLR and impairs LDL clearance from plasma.\",\n      \"method\": \"Co-immunoprecipitation, hepatocyte-specific KO mice, LDLR trafficking assay, plasma LDL measurement, live imaging\",\n      \"journal\": \"eLife\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — Co-IP of two kinesin partners, in vivo KO with defined trafficking and metabolic phenotype, multiple orthogonal methods\",\n      \"pmids\": [\"33179593\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"BLOC1S1/GCN5L1 is required for autophagic lysosome reformation (ALR). In liver-specific bloc1s1 KO hepatocytes, nutrient deprivation fails to initiate ALR due to blunted lysosomal tubulation. BLOC1S1 interacts with the ARL8B–KIF5B complex to recruit KIF5B to autolysosomes and interacts with the actin nucleation-promoting factor WHAMM. Genetic reintroduction of BLOC1S1 rescues lysosomal tubulation, but not when KIF5B is concurrently depleted, establishing epistasis. MTORC1 inhibition also abolishes BLOC1S1 reconstitution-mediated rescue of tubulation.\",\n      \"method\": \"Liver-specific KO, genetic reconstitution, Co-immunoprecipitation (ARL8B, KIF5B, WHAMM), concurrent KIF5B depletion (epistasis), MTORC1 inhibition, live imaging of lysosomal tubulation\",\n      \"journal\": \"Autophagy\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — KO with defined phenotype, genetic reconstitution rescue, epistasis by concurrent KIF5B depletion, multiple binding partners identified by Co-IP\",\n      \"pmids\": [\"33629936\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"BLOS1 interacts with KXD1, a novel 20 kDa coiled-coil protein, as confirmed by in vitro binding assays. In Kxd1 knockout mice, BLOS1 protein levels are significantly reduced, and mild defects in melanosomes and platelet dense granules (lysosome-related organelles) are observed, mimicking a mild form of Hermansky-Pudlak syndrome.\",\n      \"method\": \"Naïve Bayesian analysis, in vitro binding assay, Kxd1 KO mice, ultrastructural analysis of LROs\",\n      \"journal\": \"Traffic (Copenhagen, Denmark)\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — in vitro binding confirmed, KO mice with defined LRO phenotype, single lab\",\n      \"pmids\": [\"22554196\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"GCN5L1 promotes acetylation and inactivation of glutaminase isoforms GLS1 and GLS2 in the liver and increases enzyme oligomerization. GCN5L1 depletion in HCC cells promotes mTORC1 activation and cell proliferation; GCN5L1 levels inversely correlate with mTORC1 activity and glutaminase activity in human HCC tumors.\",\n      \"method\": \"Genetic KO, hepatocyte-specific KO mice, GLS1/2 acetylation and activity assay, orthotopic tumor assay, mTORC1 signaling analysis\",\n      \"journal\": \"Clinical and translational medicine\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — enzymatic activity assay + acetylation measurement + in vivo KO, single lab\",\n      \"pmids\": [\"35538890\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"GCN5L1 (BLOC1S1) acetylates TFAM at K76. This acetylation inhibits TFAM binding to TOM70, thereby reducing TFAM import into mitochondria and impairing mitochondrial biogenesis. In AKI, GCN5L1 is upregulated, leading to hyperacetylation of TFAM at K76. Renal tubule-specific GCN5L1 knockdown attenuates AKI-induced mitochondrial impairment.\",\n      \"method\": \"Acetylated proteomics, Duolink proximity ligation assay, Co-immunoprecipitation, site-specific acetylation mapping, genetic KD in vivo\",\n      \"journal\": \"Journal of translational medicine\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — acetylation site mapped by proteomics, protein–protein interaction confirmed by PLA and Co-IP, in vivo KD, single lab\",\n      \"pmids\": [\"36474281\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"Brucella activates RIDD (regulated IRE1-dependent decay) of Bloc1s1 mRNA to subvert innate immune defense. Inactivation of Bloc1s1 impairs BORC assembly, causing perinuclear trafficking of Brucella-containing vacuoles and enhanced susceptibility. The RIDD-resistant Bloc1s1 variant maintains BORC integrity and promotes centrifugal lysosome trafficking, resulting in lysosomal destruction of Brucella. Coronavirus MHV also exploits the RIDD–BLOS1 axis to promote replication.\",\n      \"method\": \"RIDD-deficient cell lines, RIDD-incompetent IRE1α knock-in mice, Bloc1s1 KO, BORC assembly assay, lysosome trafficking imaging, infection susceptibility assay\",\n      \"journal\": \"eLife\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — multiple genetic models (RIDD-deficient cells and mice, KO cells), BORC assembly readout, functional infection assay, validated in two independent pathogens\",\n      \"pmids\": [\"35587649\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"BLOC1S1 depletion in hepatocytes increases lysosomal content, lysosomal lipid uptake, and lipolysis independently of macro- and chaperone-mediated lipophagy but dependent on total lysosome content. Genetic induction of lysosomal biogenesis in transformed hepatocytes replicates depletion of intracellular lipid stores.\",\n      \"method\": \"Liver-specific KO mice, iPSC-derived hepatocyte-like cells (HLCs), lysosomal enzyme activity assay, lipid staining, lysosomal content measurement\",\n      \"journal\": \"Biochemical and biophysical research communications\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — KO mouse model and human iPSC-derived HLCs, multiple lipid and lysosomal readouts, single lab\",\n      \"pmids\": [\"36535215\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"IRE1-mediated degradation of Blos1 mRNA enhances ESCRT-dependent endosomal microautophagy of mutant Huntingtin (mHTT), reducing accumulation of mHTT aggregates. Overriding Blos1 degradation causes excessive mHTT aggregate accumulation in cultured cells and primary neurons. Before large aggregates form, mHTT is degraded via ESCRT-dependent, macroautophagy-independent microautophagy, and this pathway is enhanced by Blos1 degradation.\",\n      \"method\": \"Uncleavable Blos1 mutant overexpression, ESCRT loss-of-function, primary neuron culture, mHTT aggregate quantification\",\n      \"journal\": \"Molecular biology of the cell\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — genetic rescue with uncleavable mutant, ESCRT epistasis, validated in primary neurons, single lab replicating prior findings\",\n      \"pmids\": [\"36044348\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"GCN5L1 directly binds GPD2 (glycerol phosphate dehydrogenase 2, a key component of the mitochondrial glycerol phosphate shuttle) and modulates its activity. GCN5L1 deletion dramatically inhibits glucose production from glycerol and lactate due to increased cytosolic redox state, linked to altered GPD2 activity.\",\n      \"method\": \"Co-immunoprecipitation, genetic deletion, glucose production assay, cytosolic redox measurement, GPD2 activity assay\",\n      \"journal\": \"Biochemical and biophysical research communications\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — direct binding demonstrated by Co-IP, enzymatic activity and metabolic readouts, single lab\",\n      \"pmids\": [\"35802941\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"GCN5L1 promotes Drp1 acetylation to enhance mitochondrial fission in ischemic neuronal cells. Ischemia/hypoxia induces CDK5 upregulation which activates AMPK, facilitating GCN5L1–Drp1 interaction and subsequent Drp1 acetylation; this promotes mitochondrial fission and neuronal apoptosis. GCN5L1 knockdown reduces Drp1 acetylation and mitochondrial fission; AMPK inhibition also blocks Drp1 acetylation. GCN5L1 overexpression enhances Drp1 acetylation and fission.\",\n      \"method\": \"Co-immunoprecipitation, genetic KD/OE, AMPK inhibition, CDK5 pathway analysis, mitochondrial morphology assay, dMCAO mouse model\",\n      \"journal\": \"Molecular medicine (Cambridge, Mass.)\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — Co-IP, KD/OE with acetylation and morphological readouts, pharmacological epistasis, in vivo validation, single lab\",\n      \"pmids\": [\"39390372\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"GCN5L1 is present in both mitochondria and lamellar bodies (LBs) in alveolar epithelial cells. Knockout of GCN5L1 results in smaller, accumulated LB-like organelles indicating both biogenesis and trafficking defects. Reconstruction of mitochondrial GCN5L1 rescues organelle morphology but not the trafficking defect, indicating distinct roles for mitochondrial vs. non-mitochondrial GCN5L1. Loss of GCN5L1 also activates the ROS-Erk-Foxo1-Cebpα axis to downregulate surfactant-related genes.\",\n      \"method\": \"CRISPR KO, lentiviral reconstitution (mitochondrial-targeted), TEM, immunofluorescence, RNA-seq, ELISA, lipid measurement\",\n      \"journal\": \"Cellular & molecular biology letters\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — CRISPR KO with targeted reconstitution, multiple cellular readouts, single lab\",\n      \"pmids\": [\"37936104\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"GCN5L1 mediates acetylation of Rictor in cardiomyocytes, preventing its proteasomal degradation under hypoxic stress. GCN5L1 knockdown reduces Rictor acetylation and protein levels after hypoxia; GCN5L1 overexpression blocks hypoxia-induced Rictor loss. This protects cytoprotective Akt/mTORC2 signaling. Rictor degradation under hypoxia is proteasome-mediated and antagonized by increased acetylation.\",\n      \"method\": \"Co-immunoprecipitation, knockdown/overexpression, Rictor acetylation assay, proteasome inhibition, Akt/mTORC2 signaling measurement\",\n      \"journal\": \"Cellular signalling\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — direct binding, acetylation-dependent stability established by OE/KD and proteasome inhibition, single lab\",\n      \"pmids\": [\"38281616\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"GCN5L1 coordinates with YME1L protease and the MICOS component MIC13 to remodel mitochondrial cristae in white adipocytes. GCN5L1 protein interacts with MIC13 and YME1L in the mitochondrial intermembrane space; its accumulation during high-fat diet feeding facilitates MIC13/MICOS degradation and cristae disassembly, reducing OXPHOS complex stability and enhancing adipocyte expansion. White adipose-specific GCN5L1 KO increases cristae content, stabilizes OXPHOS complexes, and resists obesity.\",\n      \"method\": \"Protein interactome analysis, Co-IP, adipose-specific KO mice, electron microscopy for cristae analysis, OXPHOS complex activity assay\",\n      \"journal\": \"Cell reports\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — interactome Co-IP, tissue-specific KO, structural (EM) and biochemical readouts, single lab\",\n      \"pmids\": [\"40338741\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"BLOC1S1/GCN5L1 is significantly upregulated in ALS patient-derived motor neurons, postmortem motor cortices, and spinal cords of ALS mouse models. BLOC1S1 depletion (via splice-switching antisense oligonucleotides inducing NMD) rescues mitochondrial respiration and ALS-relevant cellular deficits in iPSC-derived motor neurons from diverse genetic backgrounds, and extends survival in an ALS mouse model.\",\n      \"method\": \"iPSC-derived motor neurons, splice-switching ASO, mitochondrial respiration assay, ALS mouse model survival, postmortem patient tissue\",\n      \"journal\": \"Molecular therapy\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — KD with defined mitochondrial and in vivo phenotype, multiple genetic backgrounds, single lab\",\n      \"pmids\": [\"41383013\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2026,\n      \"finding\": \"BLOC1S1 KO impairs anterograde transport of lysosomes and autophagy in both non-neuronal cells and iPSC-derived neurons. Most pathogenic BLOC1S1 variants exhibit reduced expression, decreased assembly with BORC/BLOC-1 subunits, and/or impaired rescue of lysosome transport and autophagy in BLOC1S1-KO cells. Evidence indicates loss of BLOC1S1 leads to more pronounced deficits in BORC function than in BLOC-1 function.\",\n      \"method\": \"BLOC1S1 KO cell lines, iPSC-derived neurons, transfection rescue experiments, lysosome transport assay, autophagy assay, BORC/BLOC-1 assembly assay, melanocytic pigmentation assay\",\n      \"journal\": \"American journal of human genetics\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — KO rescue experiments with multiple variants, multiple cell types including iPSC-neurons, multiple orthogonal readouts (lysosome transport, autophagy, pigmentation, complex assembly)\",\n      \"pmids\": [\"41887224\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2026,\n      \"finding\": \"GCN5L1 undergoes stimulus-dependent translocation from mitochondria to the cytoplasm during lipid overload and high-fat diet feeding. Cytoplasmic GCN5L1 binds PPARγ and promotes its acetylation at K289, protecting PPARγ from ubiquitination-mediated proteasomal degradation. PPARγ-K289 mutation reduces ubiquitination of PPARγ and exacerbates liver steatosis in mice, establishing GCN5L1 as a mitochondrial retrograde signal controlling hepatic lipid synthesis via PPARγ stabilization.\",\n      \"method\": \"Subcellular fractionation, Co-immunoprecipitation, acetylation site mapping (K289), PPARγ-K289 mutant mice, transcriptome and proteome analysis, ubiquitination assay\",\n      \"journal\": \"JCI insight\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — direct binding confirmed, specific acetylation site identified, in vivo KI mutant, single lab\",\n      \"pmids\": [\"41574605\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"GCN5L1 does not possess intrinsic acetyltransferase activity (as shown by functional-domain sequence alignment and experimental studies), yet supports protein acetylation in mitochondria and cytosol by acting as a subunit of numerous multiprotein complexes.\",\n      \"method\": \"Functional domain analysis, experimental studies (cited in review)\",\n      \"journal\": \"Biochimica et biophysica acta. Gene regulatory mechanisms\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 4 / Weak — review summarizing prior experimental data, no new primary experiments described\",\n      \"pmids\": [\"32599084\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"GCN5L1 deficiency in HCC cells increases sorafenib sensitivity by downregulating the mitochondrial iron transporter CISD1, leading to mitochondrial iron accumulation, increased cellular and lipid ROS, and ferroptosis. GCN5L1 modulates mitochondrial iron homeostasis via regulation of CISD1 expression.\",\n      \"method\": \"CRISPR KO, sorafenib sensitivity assay, CISD1 expression analysis, ROS measurement, lipid peroxidation assay, in vivo orthotopic tumor model\",\n      \"journal\": \"Journal of translational medicine\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — CRISPR KO with defined mechanistic pathway (CISD1), in vitro and in vivo validation, single lab\",\n      \"pmids\": [\"38918793\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"BLOC1S1 sequesters TDP-43 in the cytoplasm, inhibiting its nuclear translocation-dependent ATG7 mRNA stabilization and autophagy induction. Co-immunoprecipitation confirmed direct interaction between BLOC1S1 and TDP-43. BLOC1S1 overexpression attenuates autophagy and reduces autolysosome formation in goat spermatogonial stem cells challenged with Brucella LPS.\",\n      \"method\": \"Co-immunoprecipitation, subcellular localization (immunofluorescence), BLOC1S1 overexpression, TEM, LC3B-II/I ratio, RNA-seq and proteomics\",\n      \"journal\": \"Advanced science\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — Co-IP and localization in single model cell type (goat SSCs), single lab, partial mechanistic follow-up\",\n      \"pmids\": [\"40936170\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"BLOC1S1/GCN5L1/BLOS1 is a multifunctional scaffold protein that exists as both mitochondrial and cytosolic isoforms and acts as a shared subunit of the BLOC-1 and BORC multiprotein complexes: in the mitochondria it promotes protein acetylation (of respiratory chain proteins, FAO enzymes, Drp1, TFAM, Rictor, glutaminase, and PDH) to regulate metabolism and dynamics, while in the endolysosomal compartment it coordinates BORC-dependent anterograde lysosome transport (via ARL8B–KIF5B), autophagic lysosome reformation (via WHAMM and KIF5B), and endosomal recycling (via KIF13A/KIF3); its mRNA is also a specific IRE1 RIDD target, whose degradation repositions lysosomes to the MTOC to promote microautophagy of protein aggregates under ER stress.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"BLOC1S1 (BLOS1/GCN5L1) is a small multifunctional scaffold that operates in two distinct cellular arenas: as a shared subunit of the BLOC-1 and BORC complexes governing endolysosomal organelle biogenesis and transport, and as a mitochondrial regulator of protein acetylation and metabolism [#0, #1, #26]. It was first defined as a BLOC-1 subunit whose stability is interdependent with the other subunits (Pallidin, Muted, Cappuccino, Dysbindin) and the accessory partner KXD1, with loss producing lysosome-related organelle defects reminiscent of Hermansky-Pudlak syndrome [#0, #14]. In the endolysosomal system it drives BORC-dependent anterograde lysosome positioning and autophagy, with most pathogenic BLOC1S1 variants showing reduced complex assembly and impaired rescue of lysosome transport, a phenotype more severe for BORC than for BLOC-1 function [#26]. It coordinates microtubule motors for organelle movement, acting as an adaptor linking kinesin-3 (KIF13A) and kinesin-2 (KIF3) for recycling-endosome transport that delivers LDLR to the plasma membrane, and recruiting the ARL8B-KIF5B machinery together with the actin nucleator WHAMM to enable mTORC1-dependent autophagic lysosome reformation [#12, #13]. It also supports lysosomal degradative trafficking of EGFR via SNX2 and TSG101 [#3]. Although it lacks intrinsic enzymatic activity, mitochondrial BLOC1S1/GCN5L1 promotes acetylation of numerous targets — respiratory chain proteins counteracting SIRT3, fatty-acid-oxidation enzymes (HADHA, LCAD, SCAD) and PDH, the fission factor Drp1, TFAM, Rictor, and glutaminase — thereby tuning oxidative metabolism, mitochondrial biogenesis and turnover, cristae remodeling, and retrograde ROS-ERK-FoxO1 signaling [#1, #5, #9, #11, #16, #21, #24]. Its mRNA is a specific RIDD substrate of IRE1, and IRE1-driven Blos1 degradation repositions lysosomes to the MTOC to promote ESCRT-dependent microautophagy of protein aggregates and to control intracellular pathogen trafficking [#4, #10, #17, #19]. Loss-of-function or dysregulation links BLOC1S1 to disease: pathogenic variants cause a lysosome-transport disorder, and its upregulation contributes to mitochondrial deficits in ALS [#25, #26].\",\n  \"teleology\": [\n    {\n      \"year\": 2004,\n      \"claim\": \"Established BLOC1S1 as a bona fide structural subunit of the BLOC-1 complex, defining its founding role in lysosome-related organelle biogenesis.\",\n      \"evidence\": \"Co-IP, size exclusion chromatography, yeast two-hybrid, and pallid mouse genetics\",\n      \"pmids\": [\"15102850\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not resolve BLOC-1 architecture at residue level\", \"Did not address non-BLOC-1 functions\"]\n    },\n    {\n      \"year\": 2012,\n      \"claim\": \"Identified BLOC1S1/GCN5L1 as a mitochondrial-enriched regulator that supports protein acetylation antagonizing SIRT3, opening an entirely separate functional axis from BLOC-1.\",\n      \"evidence\": \"Knockdown, mitochondrial reconstitution, in vitro acetylation and respiration assays\",\n      \"pmids\": [\"22309213\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Whether GCN5L1 itself catalyzes acetylation or scaffolds an acetyltransferase was unresolved\", \"Specific substrate residues not mapped\"]\n    },\n    {\n      \"year\": 2012,\n      \"claim\": \"Connected BLOC1S1 to the accessory factor KXD1 and to lysosome-related organelle integrity, reinforcing subunit-interdependent stability.\",\n      \"evidence\": \"In vitro binding assay and Kxd1 KO mice with LRO ultrastructural defects\",\n      \"pmids\": [\"22554196\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Mechanism by which KXD1 stabilizes BLOS1 unclear\", \"Mild phenotype leaves redundancy unaddressed\"]\n    },\n    {\n      \"year\": 2013,\n      \"claim\": \"Showed GCN5L1 negatively regulates mitochondrial turnover by restraining a coordinated TFEB/PGC-1\\u03b1 program, linking it to autophagy and biogenesis balance.\",\n      \"evidence\": \"KO/knockdown with gene expression and mitochondrial content assays, dual-knockdown epistasis\",\n      \"pmids\": [\"24356961\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct molecular target connecting GCN5L1 to TFEB not identified\", \"Single lab\"]\n    },\n    {\n      \"year\": 2014,\n      \"claim\": \"Demonstrated a BLOC1S1 role in endosomal sorting by linking it to SNX2 and TSG101 to drive lysosomal degradation of EGFR.\",\n      \"evidence\": \"Reciprocal Co-IP, KD/KO MEFs and rescue, EGFR trafficking assay\",\n      \"pmids\": [\"25183008\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Whether this reflects BLOC-1, BORC, or retromer-specific activity unclear\", \"Single lab\"]\n    },\n    {\n      \"year\": 2015,\n      \"claim\": \"Defined BLOC1S1 mRNA as a specific, conserved RIDD target cleaved by IRE1 at a mapped site, establishing post-transcriptional control under ER stress.\",\n      \"evidence\": \"qPCR, bioinformatics, cleavage-site mutagenesis, IRE1 RNase inhibitor in cancer cells\",\n      \"pmids\": [\"25870107\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Functional consequence for acute ER-stress recovery was negative\", \"Downstream effect of Blos1 loss not yet defined here\"]\n    },\n    {\n      \"year\": 2017,\n      \"claim\": \"Extended GCN5L1's metabolic reach by showing it promotes acetylation of FAO enzymes and PDH and a TDH-coupled acetylation of KBP, regulating cardiac fatty acid oxidation and stem-cell mitochondrial biogenesis.\",\n      \"evidence\": \"Knockdown with acetylation/activity assays, HFD mice; acetylation-site mapping and Fbxo15/Kif1B genetic epistasis in mESCs\",\n      \"pmids\": [\"28526709\", \"28319092\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Mechanism of substrate selection by GCN5L1 unresolved\", \"Tissue-specificity of acetylation targets unclear\"]\n    },\n    {\n      \"year\": 2017,\n      \"claim\": \"Established GCN5L1 as a node in mitochondrial retrograde signaling controlling hepatic gluconeogenesis via ROS-ERK-FoxO1.\",\n      \"evidence\": \"Liver-specific KO, ERK inhibition, mitochondrial-targeted reconstitution, ROS and proteasome assays\",\n      \"pmids\": [\"28900165\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Direct mitochondrial acetylation substrate triggering ROS not pinpointed\", \"Single study\"]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"Linked GCN5L1 to cytoskeletal acetylation and lysosome positioning through \\u03b1TAT1 and RanBP2, bridging its mitochondrial and trafficking roles.\",\n      \"evidence\": \"Co-IP, knockdown phenocopy, \\u03b1-tubulin acetylation and lysosome positioning assays, HDAC inhibitor\",\n      \"pmids\": [\"30333138\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Whether GCN5L1 directly acetylates tubulin vs. recruits \\u03b1TAT1 unclear\", \"Single lab\"]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"Mapped specific HADHA acetylation sites regulated by GCN5L1/SIRT3, tying GCN5L1 to hepatic lipid handling and protection from diet-induced steatosis.\",\n      \"evidence\": \"Transgenic OE, proteomic site mapping, stable KD, liver-specific KO, enzymatic assays\",\n      \"pmids\": [\"30323061\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"In vivo stoichiometry of site occupancy unclear\", \"Single lab\"]\n    },\n    {\n      \"year\": 2019,\n      \"claim\": \"Resolved the functional purpose of IRE1-mediated Blos1 decay: lysosome repositioning to the MTOC enables ESCRT-dependent microautophagy of ubiquitinated aggregates under ER stress.\",\n      \"evidence\": \"Uncleavable Blos1 mutant rescue, live imaging, ESCRT loss-of-function, aggregate detection\",\n      \"pmids\": [\"30787040\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"How reduced BLOS1 mechanistically shifts lysosome polarity not fully defined\", \"Link to BORC disassembly not yet shown here\"]\n    },\n    {\n      \"year\": 2019,\n      \"claim\": \"Showed GCN5L1 binds and acetylates Rictor to sustain mTORC2/Akt signaling and limit mitochondrial ROS in cardiomyocyte stress.\",\n      \"evidence\": \"Co-IP, knockdown, Rictor acetylation rescue, hypoxia-reoxygenation survival assay\",\n      \"pmids\": [\"31138772\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Acetylation site on Rictor not mapped in this study\", \"Single lab\"]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Defined BLOS1 as a dual kinesin adaptor (KIF13A and KIF3) coordinating long-range anterograde recycling-endosome transport that controls LDLR surface delivery and plasma LDL clearance.\",\n      \"evidence\": \"Co-IP, hepatocyte-specific KO mice, LDLR trafficking and LDL measurement, live imaging\",\n      \"pmids\": [\"33179593\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"How BLOS1 switches between motor types unclear\", \"Relationship to BORC complex in this role not defined\"]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"Established BLOC1S1 as required for autophagic lysosome reformation by recruiting ARL8B-KIF5B and WHAMM to drive mTORC1-dependent lysosomal tubulation.\",\n      \"evidence\": \"Liver-specific KO, reconstitution rescue, Co-IP, concurrent KIF5B depletion epistasis, MTORC1 inhibition, live imaging\",\n      \"pmids\": [\"33629936\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Order of WHAMM actin nucleation vs. KIF5B recruitment unclear\", \"Single lab\"]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"Clarified that GCN5L1 lacks intrinsic acetyltransferase activity and instead functions as a multi-complex scaffold supporting acetylation.\",\n      \"evidence\": \"Functional-domain alignment and review of prior experimental data\",\n      \"pmids\": [\"32599084\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"Review without new primary experiments\", \"Identity of the catalytic enzyme(s) it scaffolds not established\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Expanded the metabolic substrate repertoire (glutaminase, TFAM, GPD2) and connected GCN5L1 to mTORC1 activity, mitochondrial biogenesis, and redox-coupled gluconeogenesis.\",\n      \"evidence\": \"Hepatocyte-specific KO, acetylation/activity assays, PLA and Co-IP, glucose production and redox assays, HCC tumor models\",\n      \"pmids\": [\"35538890\", \"36474281\", \"35802941\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Whether TFAM/glutaminase acetylation is direct or scaffold-mediated unresolved\", \"Single labs per substrate\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Generalized the RIDD-BLOS1 axis to host-pathogen conflict, showing IRE1-driven Blos1 decay disrupts BORC assembly and lysosome positioning to either restrict or be exploited by intracellular pathogens.\",\n      \"evidence\": \"RIDD-deficient cells and IRE1\\u03b1 knock-in mice, Bloc1s1 KO, BORC assembly and lysosome imaging, Brucella and coronavirus infection assays\",\n      \"pmids\": [\"35587649\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"How BLOS1 loss biochemically destabilizes BORC not detailed\", \"Generalizability beyond tested pathogens unclear\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Reinforced the aggregate-clearance role by showing Blos1 decay enhances ESCRT-dependent microautophagy of mutant Huntingtin in neurons.\",\n      \"evidence\": \"Uncleavable Blos1 mutant, ESCRT loss-of-function, primary neuron mHTT quantification\",\n      \"pmids\": [\"36044348\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Whether basal BLOS1 levels limit clearance in disease unclear\", \"Single lab replicating prior work\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Linked BLOC1S1 lysosomal control to hepatic lipid storage, with depletion raising lysosomal content and lipolysis independent of canonical lipophagy.\",\n      \"evidence\": \"Liver-specific KO mice and iPSC-derived hepatocytes with lysosomal and lipid readouts\",\n      \"pmids\": [\"36535215\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Mechanism coupling BLOC1S1 loss to lysosome biogenesis unclear\", \"Single lab\"]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Demonstrated functionally separable mitochondrial vs. non-mitochondrial GCN5L1 pools in alveolar cells, where mitochondrial reconstitution rescues organelle morphology but not trafficking.\",\n      \"evidence\": \"CRISPR KO, mitochondrial-targeted reconstitution, TEM, RNA-seq, lipid measurement\",\n      \"pmids\": [\"37936104\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Molecular basis of pool partitioning not defined\", \"Single lab\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Added Drp1 acetylation as a GCN5L1 output controlling mitochondrial fission and neuronal apoptosis downstream of CDK5-AMPK in ischemia.\",\n      \"evidence\": \"Co-IP, KD/OE, AMPK inhibition, mitochondrial morphology, dMCAO mouse model\",\n      \"pmids\": [\"39390372\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Drp1 acetylation site not mapped\", \"Single lab\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Showed GCN5L1 stabilizes Rictor via acetylation against proteasomal degradation under hypoxia and modulates ferroptosis sensitivity via CISD1-dependent mitochondrial iron homeostasis in HCC.\",\n      \"evidence\": \"Co-IP, KD/OE with proteasome inhibition; CRISPR KO with sorafenib sensitivity, ROS, lipid peroxidation, tumor models\",\n      \"pmids\": [\"38281616\", \"38918793\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Whether CISD1 regulation is acetylation-dependent unclear\", \"Single labs\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Defined a cristae-remodeling role via GCN5L1 interaction with YME1L and MIC13/MICOS that degrades cristae junctions and promotes adipocyte expansion in obesity.\",\n      \"evidence\": \"Interactome Co-IP, adipose-specific KO, EM cristae analysis, OXPHOS activity assays\",\n      \"pmids\": [\"40338741\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Whether MIC13 degradation requires acetylation unclear\", \"Single lab\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Implicated GCN5L1 in stimulus-dependent mitochondria-to-cytoplasm translocation that stabilizes PPAR\\u03b3 by K289 acetylation, and in ALS pathology where its upregulation impairs motor-neuron mitochondria.\",\n      \"evidence\": \"Subcellular fractionation, Co-IP, K289 site mapping, PPAR\\u03b3-KI mice; iPSC motor neurons, splice-switching ASO, ALS mouse survival, postmortem tissue\",\n      \"pmids\": [\"41574605\", \"41383013\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Trigger and machinery for translocation not defined\", \"Causality of GCN5L1 upregulation in human ALS unproven\"]\n    },\n    {\n      \"year\": 2026,\n      \"claim\": \"Connected BLOC1S1 to human Mendelian disease, showing pathogenic variants impair BORC/BLOC-1 assembly and lysosome transport with BORC function more affected than BLOC-1.\",\n      \"evidence\": \"BLOC1S1-KO cells and iPSC neurons, variant rescue, lysosome transport, autophagy, pigmentation, complex-assembly assays\",\n      \"pmids\": [\"41887224\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Genotype-phenotype correlation across variants incomplete\", \"Mechanism of differential BORC vs BLOC-1 sensitivity unclear\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"It remains unresolved how a single non-catalytic scaffold partitions between mitochondrial acetylation and endolysosomal trafficking roles, and which acetyltransferase(s) GCN5L1 actually scaffolds.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"Identity of the catalytic enzyme supported by GCN5L1 unknown\", \"Regulation of subcellular pool partitioning undefined\", \"Structural basis for shared BORC/BLOC-1 subunit usage not determined\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0060090\", \"supporting_discovery_ids\": [12, 13, 0]},\n      {\"term_id\": \"GO:0140096\", \"supporting_discovery_ids\": [1, 9, 16, 21]},\n      {\"term_id\": \"GO:0005198\", \"supporting_discovery_ids\": [0, 26]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005739\", \"supporting_discovery_ids\": [1, 7, 24]},\n      {\"term_id\": \"GO:0005829\", \"supporting_discovery_ids\": [27, 30]},\n      {\"term_id\": \"GO:0005764\", \"supporting_discovery_ids\": [13, 17, 8]},\n      {\"term_id\": \"GO:0005768\", \"supporting_discovery_ids\": [3, 12]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-5653656\", \"supporting_discovery_ids\": [3, 12, 13]},\n      {\"term_id\": \"R-HSA-9612973\", \"supporting_discovery_ids\": [13, 10, 19]},\n      {\"term_id\": \"R-HSA-1430728\", \"supporting_discovery_ids\": [5, 9, 15]},\n      {\"term_id\": \"R-HSA-8953854\", \"supporting_discovery_ids\": [4, 10, 17]},\n      {\"term_id\": \"R-HSA-9609507\", \"supporting_discovery_ids\": [12, 13, 17]}\n    ],\n    \"complexes\": [\"BLOC-1\", \"BORC\"],\n    \"partners\": [\"KIF5B\", \"ARL8B\", \"WHAMM\", \"KIF13A\", \"KIF3\", \"RICTOR\", \"SNX2\", \"KXD1\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":8,"faith_total":8,"faith_pct":100.0}}