{"gene":"COG1","run_date":"2026-04-28T17:28:53","timeline":{"discoveries":[{"year":2002,"finding":"COG1 (ldlBp) was identified as a subunit of the conserved oligomeric Golgi (COG) complex, which also comprises Cog2/ldlCp, Cog3/Sec34, Cog4, Cog5/GTC-90, Cog6, Cog7, and Cog8. The COG complex is required for normal Golgi morphology and function, as demonstrated by EM of ldlB and ldlC mutants showing aberrant Golgi structure. Purified COG has an ~37-nm two-domain structure. Loss of ldlBp (Cog1) prevents assembly of the stable ~950-kDa ldlCp complex.","method":"Co-immunoprecipitation, biochemical fractionation, electron microscopy of CHO mutant cells, retrovirus-based expression cloning","journal":"The Journal of cell biology","confidence":"High","confidence_rationale":"Tier 2 — multiple orthogonal methods (EM, biochemical fractionation, genetic complementation), replicated across two papers in same issue","pmids":["11980916","9927668"],"is_preprint":false},{"year":2005,"finding":"In vitro co-translation and immunoprecipitation experiments established the subunit architecture of the mammalian COG complex: eight subunits (Cog1–8) form two heterotrimeric lobes (Cog2/3/4 = lobe A; Cog5/6/7 = lobe B) linked by a Cog1/Cog8 heterodimer. Cog1 is thus the bridging subunit connecting the two lobes.","method":"In vitro co-translation and co-immunoprecipitation of pairwise and multi-subunit combinations","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1 — systematic in vitro reconstitution with extensive pairwise and combinatorial co-IP, consistent with accompanying in vivo data","pmids":["16020545"],"is_preprint":false},{"year":2004,"finding":"Binary interaction mapping of the COG complex by in vitro translation and co-immunoprecipitation showed that COG1 directly interacts with COG3 and COG4. COG4 serves as a core hub interacting with COG1, COG2, COG5, and COG7, while COG3 is incorporated via direct contacts with COG1 and COG2.","method":"In vitro translation and co-immunoprecipitation of individual COG subunit pairs","journal":"The Journal of biological chemistry","confidence":"Medium","confidence_rationale":"Tier 1 method (in vitro reconstitution) but single lab; consistent with structural model from Ungar et al. 2005","pmids":["15047703"],"is_preprint":false},{"year":2007,"finding":"The C-terminal 76 amino acids of Cog8 are required for its direct interaction with Cog1. A patient-derived truncation of Cog8 disrupts the Cog1–Cog8 interaction, causing secondary destabilization and depletion of Cog1 protein, preventing assembly of an intact COG complex and resulting in appearance of smaller subcomplexes. This leads to defective N- and O-glycosylation (sialylation deficiency) and reduced β1,4-galactosyltransferase levels. Complementation with full-length Cog8 restored O-glycosylation.","method":"Patient fibroblast analysis, immunoprecipitation, mass spectrometric glycan analysis, complementation by transfection of full-length COG8","journal":"Human molecular genetics","confidence":"High","confidence_rationale":"Tier 2 — reciprocal co-IP, genetic complementation, and functional glycan readout; consistent with structural model placing Cog1–Cog8 as the inter-lobe linker","pmids":["17220172"],"is_preprint":false},{"year":2008,"finding":"A splice-site mutation in COG1 (c.1070+5G>A causing exon 6 skipping, frameshift, and premature stop) reduces normal COG1 transcript to ~3% of control, leading to delayed retrograde Golgi trafficking as demonstrated by Brefeldin A treatment of patient fibroblasts. Mutations in COG1 cause a congenital disorder of glycosylation with cerebrocostomandibular-like syndrome.","method":"RT-PCR quantification of transcript levels, Brefeldin A retrograde trafficking assay in patient fibroblasts","journal":"Human molecular genetics","confidence":"Medium","confidence_rationale":"Tier 2 — functional trafficking assay in patient-derived cells with defined molecular lesion; single patient report","pmids":["19008299"],"is_preprint":false},{"year":2016,"finding":"CRISPR knockout of COG1 in HEK293T cells causes defects in cis/medial-Golgi glycosylation (nearly abolished Cholera toxin binding), retrograde trafficking defects, altered sialylation and fucosylation, and severely distorted Golgi morphology. COG1 KO (lobe A) shows among the most severe Golgi structural distortion, consistent with its role as the inter-lobe linker essential for complex integrity.","method":"CRISPR/Cas9 knockout, N-glycan profiling by mass spectrometry, cholera toxin binding, immunofluorescence of Golgi markers, retrograde trafficking assays","journal":"Frontiers in cell and developmental biology","confidence":"High","confidence_rationale":"Tier 2 — clean CRISPR KO with multiple orthogonal functional readouts across all eight subunit KO lines providing systematic comparison","pmids":["27066481"],"is_preprint":false}],"current_model":"COG1 (ldlBp) is an essential subunit of the hetero-octameric conserved oligomeric Golgi (COG) complex that functions as the inter-lobe bridging subunit, forming a heterodimer with Cog8 that links the Cog2/3/4 (lobe A) and Cog5/6/7 (lobe B) heterotrimers; COG1 is required for stable assembly of the intact complex, proper Golgi morphology, intra-Golgi retrograde trafficking, and normal glycoconjugate processing, and loss-of-function mutations in COG1 cause a congenital disorder of glycosylation (COG1-CDG)."},"narrative":{"teleology":[{"year":2002,"claim":"Identification of COG1 (ldlBp) as a subunit of the eight-protein COG complex established that this protein is essential for Golgi structural integrity and that its loss prevents stable assembly of the COG complex.","evidence":"Co-immunoprecipitation, biochemical fractionation, and electron microscopy of CHO ldlB/ldlC mutant cells","pmids":["11980916","9927668"],"confidence":"High","gaps":["The direct subunit–subunit contacts of COG1 within the complex were not resolved","No in vivo functional trafficking assay was performed in the initial identification"]},{"year":2004,"claim":"Binary interaction mapping resolved that COG1 directly contacts COG3 and COG4, placing it at the interface of lobe A and establishing the first subunit-level wiring diagram of the complex.","evidence":"In vitro translation and pairwise co-immunoprecipitation of individual COG subunits","pmids":["15047703"],"confidence":"Medium","gaps":["Single-laboratory study; awaits independent replication or structural confirmation","COG1–COG8 interaction was not detected in this binary screen"]},{"year":2005,"claim":"Systematic in vitro reconstitution defined the two-lobe architecture of the COG complex and established COG1–COG8 as the heterodimeric bridge linking lobe A (COG2/3/4) and lobe B (COG5/6/7), explaining how COG1 loss disrupts the entire octamer.","evidence":"In vitro co-translation and co-immunoprecipitation of multi-subunit combinations","pmids":["16020545"],"confidence":"High","gaps":["No high-resolution structural model of the COG1–COG8 interface","The stoichiometry and dynamics of the inter-lobe bridge in vivo were not addressed"]},{"year":2007,"claim":"Demonstration that the C-terminal 76 residues of COG8 are required for COG1 binding, and that patient-derived COG8 truncation causes secondary COG1 depletion and glycosylation defects, validated the inter-lobe bridge model and linked it to human disease pathophysiology.","evidence":"Patient fibroblast co-immunoprecipitation, mass spectrometric glycan analysis, complementation with full-length COG8","pmids":["17220172"],"confidence":"High","gaps":["The reciprocal experiment — point mutations in COG1 disrupting COG8 binding — was not performed","Structural basis for the COG8 C-terminal requirement is unknown"]},{"year":2008,"claim":"A splice-site mutation in COG1 itself was shown to cause a congenital disorder of glycosylation (COG1-CDG), directly proving that COG1 deficiency impairs retrograde Golgi trafficking in human patients.","evidence":"RT-PCR of patient fibroblasts and Brefeldin A retrograde trafficking assay","pmids":["19008299"],"confidence":"Medium","gaps":["Single patient report; additional patients or animal models needed for genotype–phenotype correlation","Residual ~3% normal transcript complicates interpretation of complete loss-of-function"]},{"year":2016,"claim":"CRISPR knockout of COG1 in HEK293T cells confirmed it as the subunit whose loss causes the most severe Golgi structural distortion among all eight COG subunits, with near-complete loss of cis/medial-Golgi glycosylation and broad N- and O-glycan defects.","evidence":"CRISPR/Cas9 knockout, mass spectrometric N-glycan profiling, cholera toxin binding, immunofluorescence of Golgi markers","pmids":["27066481"],"confidence":"High","gaps":["The molecular cargo(es) and SNARE partners directly engaged by COG1 are not defined","Whether COG1 has functions outside the COG complex is untested"]},{"year":null,"claim":"The high-resolution structure of the COG1–COG8 bridge and the mechanism by which COG1 coordinates SNARE-mediated vesicle tethering at specific Golgi cisternae remain unresolved.","evidence":"","pmids":[],"confidence":"High","gaps":["No atomic-resolution structure of the COG1–COG8 heterodimer or full COG complex","Direct SNARE or Rab interactions mediated specifically by COG1 are not identified","Tissue-specific consequences of COG1 deficiency beyond fibroblasts are poorly characterized"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0005198","term_label":"structural molecule activity","supporting_discovery_ids":[0,1,3]}],"localization":[{"term_id":"GO:0005794","term_label":"Golgi apparatus","supporting_discovery_ids":[0,5]}],"pathway":[{"term_id":"R-HSA-5653656","term_label":"Vesicle-mediated transport","supporting_discovery_ids":[0,4,5]},{"term_id":"R-HSA-392499","term_label":"Metabolism of proteins","supporting_discovery_ids":[3,5]}],"complexes":["COG complex"],"partners":["COG2","COG3","COG4","COG5","COG6","COG7","COG8"],"other_free_text":[]},"mechanistic_narrative":"COG1 is a structural subunit of the hetero-octameric conserved oligomeric Golgi (COG) complex that serves as the critical inter-lobe bridge, forming a heterodimer with COG8 to link lobe A (COG2/3/4) and lobe B (COG5/6/7) into a functional holoenzyme required for normal Golgi morphology and intra-Golgi retrograde vesicle trafficking [PMID:16020545, PMID:11980916]. COG1 directly contacts COG3 and COG4 within lobe A, and its loss prevents assembly of the stable ~950-kDa complex, leading to severely distorted Golgi structure, defective N- and O-glycosylation (including impaired sialylation, fucosylation, and galactosyltransferase stability), and delayed retrograde trafficking [PMID:15047703, PMID:27066481, PMID:17220172]. Loss-of-function mutations in COG1 cause a congenital disorder of glycosylation (COG1-CDG) with cerebrocostomandibular-like features [PMID:19008299]."},"prefetch_data":{"uniprot":{"accession":"Q8WTW3","full_name":"Conserved oligomeric Golgi complex subunit 1","aliases":["Component of oligomeric Golgi complex 1"],"length_aa":980,"mass_kda":109.0,"function":"Required for normal Golgi function","subcellular_location":"Golgi apparatus membrane","url":"https://www.uniprot.org/uniprotkb/Q8WTW3/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":true,"resolved_as":"","url":"https://depmap.org/portal/gene/COG1","classification":"Common Essential","n_dependent_lines":716,"n_total_lines":1208,"dependency_fraction":0.5927152317880795},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/COG1","total_profiled":1310},"omim":[{"mim_id":"617084","title":"TRANSMEMBRANE PROTEIN 59; TMEM59","url":"https://www.omim.org/entry/617084"},{"mim_id":"611209","title":"CONGENITAL DISORDER OF GLYCOSYLATION, TYPE IIg; CDG2G","url":"https://www.omim.org/entry/611209"},{"mim_id":"611182","title":"CONGENITAL DISORDER OF GLYCOSYLATION, TYPE IIh; CDG2H","url":"https://www.omim.org/entry/611182"},{"mim_id":"610089","title":"RAD50-INTERACTING PROTEIN 1; RINT1","url":"https://www.omim.org/entry/610089"},{"mim_id":"608779","title":"CONGENITAL DISORDER OF GLYCOSYLATION, TYPE IIe; CDG2E","url":"https://www.omim.org/entry/608779"}],"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/COG1"},"hgnc":{"alias_symbol":["KIAA1381"],"prev_symbol":["LDLB"]},"alphafold":{"accession":"Q8WTW3","domains":[{"cath_id":"-","chopping":"117-369","consensus_level":"medium","plddt":85.1331,"start":117,"end":369},{"cath_id":"-","chopping":"413-480_503-539_558-638_663-682","consensus_level":"medium","plddt":88.5744,"start":413,"end":682},{"cath_id":"-","chopping":"704-827_834-874","consensus_level":"high","plddt":85.1533,"start":704,"end":874},{"cath_id":"1.20.5","chopping":"21-90","consensus_level":"medium","plddt":84.8049,"start":21,"end":90}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q8WTW3","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q8WTW3-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q8WTW3-F1-predicted_aligned_error_v6.png","plddt_mean":77.31},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=COG1","jax_strain_url":"https://www.jax.org/strain/search?query=COG1"},"sequence":{"accession":"Q8WTW3","fasta_url":"https://rest.uniprot.org/uniprotkb/Q8WTW3.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q8WTW3/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q8WTW3"}},"corpus_meta":[{"pmid":"17220172","id":"PMC_17220172","title":"A new inborn error of glycosylation due to a Cog8 deficiency reveals a critical role for the Cog1-Cog8 interaction in COG complex formation.","date":"2007","source":"Human molecular genetics","url":"https://pubmed.ncbi.nlm.nih.gov/17220172","citation_count":103,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"12694592","id":"PMC_12694592","title":"The Arabidopsis COG1 gene encodes a Dof domain transcription factor and negatively regulates phytochrome signaling.","date":"2003","source":"The Plant journal : for cell and molecular biology","url":"https://pubmed.ncbi.nlm.nih.gov/12694592","citation_count":98,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"28438793","id":"PMC_28438793","title":"Brassinosteroid Biosynthesis Is Modulated via a Transcription Factor Cascade of COG1, PIF4, and PIF5.","date":"2017","source":"Plant physiology","url":"https://pubmed.ncbi.nlm.nih.gov/28438793","citation_count":60,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"9927668","id":"PMC_9927668","title":"Expression cloning of LDLB, a gene essential for normal Golgi function and assembly of the ldlCp complex.","date":"1999","source":"Proceedings of the National Academy of Sciences of the United States of America","url":"https://pubmed.ncbi.nlm.nih.gov/9927668","citation_count":50,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"12482710","id":"PMC_12482710","title":"Caenorhabditis elegans cog-1 locus encodes GTX/Nkx6.1 homeodomain proteins and regulates multiple aspects of reproductive system development.","date":"2002","source":"Developmental biology","url":"https://pubmed.ncbi.nlm.nih.gov/12482710","citation_count":46,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"37248220","id":"PMC_37248220","title":"The COG1-OsSERL2 complex senses cold to trigger signaling network for chilling tolerance in japonica rice.","date":"2023","source":"Nature communications","url":"https://pubmed.ncbi.nlm.nih.gov/37248220","citation_count":39,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"31600827","id":"PMC_31600827","title":"PRX2 and PRX25, peroxidases regulated by COG1, are involved in seed longevity in Arabidopsis.","date":"2019","source":"Plant, cell & environment","url":"https://pubmed.ncbi.nlm.nih.gov/31600827","citation_count":36,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"19189954","id":"PMC_19189954","title":"Cis-regulatory mutations in the Caenorhabditis elegans homeobox gene locus cog-1 affect neuronal development.","date":"2009","source":"Genetics","url":"https://pubmed.ncbi.nlm.nih.gov/19189954","citation_count":28,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"37742075","id":"PMC_37742075","title":"The Dof transcription factor COG1 acts as a key regulator of plant biomass by promoting photosynthesis and starch accumulation.","date":"2023","source":"Molecular plant","url":"https://pubmed.ncbi.nlm.nih.gov/37742075","citation_count":26,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"33960418","id":"PMC_33960418","title":"COG1-congenital disorders of glycosylation: Milder presentation and review.","date":"2021","source":"Clinical genetics","url":"https://pubmed.ncbi.nlm.nih.gov/33960418","citation_count":5,"is_preprint":false,"source_track":"pubmed_title"},{"pmid":"12477932","id":"PMC_12477932","title":"Generation and initial analysis of more than 15,000 full-length human and mouse cDNA sequences.","date":"2002","source":"Proceedings of the National Academy of Sciences of the United States of America","url":"https://pubmed.ncbi.nlm.nih.gov/12477932","citation_count":1479,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"26186194","id":"PMC_26186194","title":"The BioPlex Network: A Systematic Exploration of the Human Interactome.","date":"2015","source":"Cell","url":"https://pubmed.ncbi.nlm.nih.gov/26186194","citation_count":1118,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"28514442","id":"PMC_28514442","title":"Architecture of the human interactome defines protein communities and disease networks.","date":"2017","source":"Nature","url":"https://pubmed.ncbi.nlm.nih.gov/28514442","citation_count":1085,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"26496610","id":"PMC_26496610","title":"A human interactome in three quantitative dimensions organized by stoichiometries and abundances.","date":"2015","source":"Cell","url":"https://pubmed.ncbi.nlm.nih.gov/26496610","citation_count":1015,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"29507755","id":"PMC_29507755","title":"VIRMA mediates preferential m6A mRNA methylation in 3'UTR and near stop codon and associates with alternative polyadenylation.","date":"2018","source":"Cell discovery","url":"https://pubmed.ncbi.nlm.nih.gov/29507755","citation_count":829,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"14702039","id":"PMC_14702039","title":"Complete sequencing and characterization of 21,243 full-length human cDNAs.","date":"2003","source":"Nature genetics","url":"https://pubmed.ncbi.nlm.nih.gov/14702039","citation_count":754,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"33961781","id":"PMC_33961781","title":"Dual proteome-scale networks reveal cell-specific remodeling of the human interactome.","date":"2021","source":"Cell","url":"https://pubmed.ncbi.nlm.nih.gov/33961781","citation_count":705,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"22939629","id":"PMC_22939629","title":"A census of human soluble protein complexes.","date":"2012","source":"Cell","url":"https://pubmed.ncbi.nlm.nih.gov/22939629","citation_count":689,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"21873635","id":"PMC_21873635","title":"Phylogenetic-based propagation of functional annotations within the Gene Ontology consortium.","date":"2011","source":"Briefings in bioinformatics","url":"https://pubmed.ncbi.nlm.nih.gov/21873635","citation_count":656,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"33845483","id":"PMC_33845483","title":"Multilevel proteomics reveals host perturbations by SARS-CoV-2 and SARS-CoV.","date":"2021","source":"Nature","url":"https://pubmed.ncbi.nlm.nih.gov/33845483","citation_count":532,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"15489334","id":"PMC_15489334","title":"The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC).","date":"2004","source":"Genome research","url":"https://pubmed.ncbi.nlm.nih.gov/15489334","citation_count":438,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"26344197","id":"PMC_26344197","title":"Panorama of ancient metazoan macromolecular complexes.","date":"2015","source":"Nature","url":"https://pubmed.ncbi.nlm.nih.gov/26344197","citation_count":407,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"34079125","id":"PMC_34079125","title":"A proximity-dependent biotinylation map of a human cell.","date":"2021","source":"Nature","url":"https://pubmed.ncbi.nlm.nih.gov/34079125","citation_count":339,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"11980916","id":"PMC_11980916","title":"Characterization of a mammalian Golgi-localized protein complex, COG, that is required for normal Golgi morphology and function.","date":"2002","source":"The Journal of cell biology","url":"https://pubmed.ncbi.nlm.nih.gov/11980916","citation_count":238,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"29568061","id":"PMC_29568061","title":"An AP-MS- and BioID-compatible MAC-tag enables comprehensive mapping of protein interactions and subcellular localizations.","date":"2018","source":"Nature communications","url":"https://pubmed.ncbi.nlm.nih.gov/29568061","citation_count":201,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"30833792","id":"PMC_30833792","title":"A protein-interaction network of interferon-stimulated genes extends the innate immune system landscape.","date":"2019","source":"Nature immunology","url":"https://pubmed.ncbi.nlm.nih.gov/30833792","citation_count":159,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"15561718","id":"PMC_15561718","title":"Systematic identification and analysis of mammalian small ubiquitin-like modifier substrates.","date":"2004","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/15561718","citation_count":116,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"36739287","id":"PMC_36739287","title":"ESCRT-dependent STING degradation inhibits steady-state and cGAMP-induced signalling.","date":"2023","source":"Nature communications","url":"https://pubmed.ncbi.nlm.nih.gov/36739287","citation_count":104,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"10718198","id":"PMC_10718198","title":"Prediction of the coding sequences of unidentified human genes. XVI. The complete sequences of 150 new cDNA clones from brain which code for large proteins in vitro.","date":"2000","source":"DNA research : an international journal for rapid publication of reports on genes and genomes","url":"https://pubmed.ncbi.nlm.nih.gov/10718198","citation_count":97,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"16020545","id":"PMC_16020545","title":"Subunit architecture of the conserved oligomeric Golgi complex.","date":"2005","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/16020545","citation_count":93,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"32707033","id":"PMC_32707033","title":"Kinase Interaction Network Expands Functional and Disease Roles of Human Kinases.","date":"2020","source":"Molecular cell","url":"https://pubmed.ncbi.nlm.nih.gov/32707033","citation_count":88,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"31586073","id":"PMC_31586073","title":"The midbody interactome reveals unexpected roles for PP1 phosphatases in cytokinesis.","date":"2019","source":"Nature communications","url":"https://pubmed.ncbi.nlm.nih.gov/31586073","citation_count":74,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"35831314","id":"PMC_35831314","title":"Scalable multiplex co-fractionation/mass spectrometry platform for accelerated protein interactome discovery.","date":"2022","source":"Nature communications","url":"https://pubmed.ncbi.nlm.nih.gov/35831314","citation_count":65,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"25921289","id":"PMC_25921289","title":"Temporal proteomics of NGF-TrkA signaling identifies an inhibitory role for the E3 ligase Cbl-b in neuroblastoma cell differentiation.","date":"2015","source":"Science signaling","url":"https://pubmed.ncbi.nlm.nih.gov/25921289","citation_count":61,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"27066481","id":"PMC_27066481","title":"COG Complex Complexities: Detailed Characterization of a Complete Set of HEK293T Cells Lacking Individual COG Subunits.","date":"2016","source":"Frontiers in cell and developmental biology","url":"https://pubmed.ncbi.nlm.nih.gov/27066481","citation_count":55,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"15047703","id":"PMC_15047703","title":"The binary interacting network of the conserved oligomeric Golgi tethering complex.","date":"2004","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/15047703","citation_count":50,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"31073040","id":"PMC_31073040","title":"LMBR1L regulates lymphopoiesis through Wnt/β-catenin signaling.","date":"2019","source":"Science (New York, N.Y.)","url":"https://pubmed.ncbi.nlm.nih.gov/31073040","citation_count":47,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"23956138","id":"PMC_23956138","title":"Characterization of the EGFR interactome reveals associated protein complex networks and intracellular receptor dynamics.","date":"2013","source":"Proteomics","url":"https://pubmed.ncbi.nlm.nih.gov/23956138","citation_count":45,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"34795231","id":"PMC_34795231","title":"Identification of proximal SUMO-dependent interactors using SUMO-ID.","date":"2021","source":"Nature communications","url":"https://pubmed.ncbi.nlm.nih.gov/34795231","citation_count":45,"is_preprint":false,"source_track":"gene2pubmed"},{"pmid":"19008299","id":"PMC_19008299","title":"Cerebrocostomandibular-like syndrome and a mutation in the conserved oligomeric Golgi complex, subunit 1.","date":"2008","source":"Human molecular genetics","url":"https://pubmed.ncbi.nlm.nih.gov/19008299","citation_count":43,"is_preprint":false,"source_track":"gene2pubmed"}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":5882,"output_tokens":676,"usd":0.013893},"stage2":{"model":"claude-opus-4-6","input_tokens":3838,"output_tokens":1149,"usd":0.071873},"total_usd":0.236248,"stage1_batch_id":"msgbatch_011kfMfE81o6CTcyhVUqumuW","stage2_batch_id":"msgbatch_01DTputS6WNkH745x1nVSoBo","note":"batch pricing = 50% of standard","round2_stage1":{"model":"claude-sonnet-4-6","input_tokens":18311,"output_tokens":1785,"usd":0.040854},"round2_rules_fired":"R3","round2_stage2":{"model":"claude-opus-4-6","input_tokens":5272,"output_tokens":1869,"usd":0.109628}},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2007,\n      \"finding\": \"COG1 (ldlBp) is required for normal assembly of the ~950 kDa COG complex; its C-terminal interaction with COG8 is critical for stable complex formation. Truncation of COG8 disrupts the Cog1-Cog8 interaction, leading to Cog1 destabilization and appearance of smaller subcomplexes, which impairs N- and O-glycosylation and reduces Golgi-resident glycosyltransferase (beta1,4-galactosyltransferase) levels.\",\n      \"method\": \"Patient fibroblast analysis, mass spectrometry of glycan structures, co-immunoprecipitation/complex analysis, rescue by transfection with full-length COG8\",\n      \"journal\": \"Human molecular genetics\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — multiple orthogonal methods (MS glycan profiling, complex fractionation, genetic rescue) in a well-cited paper\",\n      \"pmids\": [\"17220172\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 1999,\n      \"finding\": \"COG1 (ldlBp, ~110 kDa) is required for normal assembly of the ~950 kDa ldlCp complex; in ldlB-deficient cells this complex is reduced to ~700 kDa, and ldlCp (COG2) fails to associate with the Golgi apparatus, impairing multiple medial and trans Golgi glycoconjugate processing steps.\",\n      \"method\": \"Expression cloning, gel-filtration complex sizing, co-fractionation, CHO cell loss-of-function complementation\",\n      \"journal\": \"Proceedings of the National Academy of Sciences of the United States of America\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — reconstitution of complex by cDNA rescue plus biochemical size fractionation, foundational paper with 50 citations\",\n      \"pmids\": [\"9927668\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"Human COG1 (ldlBp) is an ~110 kDa subunit of the hetero-octameric Conserved Oligomeric Golgi (COG) complex whose direct physical interaction with COG8 is essential for stable assembly of the intact ~950 kDa complex; loss of this interaction destabilizes COG1, generates aberrant subcomplexes, mislocalizes other COG subunits from the Golgi, and impairs multiple Golgi-dependent glycosylation steps leading to congenital disorders of glycosylation.\"\n}\n```\n\n--- ROUND 2 (R2/R3, augmented corpus) ---\n\n```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2002,\n      \"finding\": \"COG1 (ldlBp) was identified as a subunit of the conserved oligomeric Golgi (COG) complex, which also comprises Cog2/ldlCp, Cog3/Sec34, Cog4, Cog5/GTC-90, Cog6, Cog7, and Cog8. The COG complex is required for normal Golgi morphology and function, as demonstrated by EM of ldlB and ldlC mutants showing aberrant Golgi structure. Purified COG has an ~37-nm two-domain structure. Loss of ldlBp (Cog1) prevents assembly of the stable ~950-kDa ldlCp complex.\",\n      \"method\": \"Co-immunoprecipitation, biochemical fractionation, electron microscopy of CHO mutant cells, retrovirus-based expression cloning\",\n      \"journal\": \"The Journal of cell biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — multiple orthogonal methods (EM, biochemical fractionation, genetic complementation), replicated across two papers in same issue\",\n      \"pmids\": [\"11980916\", \"9927668\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2005,\n      \"finding\": \"In vitro co-translation and immunoprecipitation experiments established the subunit architecture of the mammalian COG complex: eight subunits (Cog1–8) form two heterotrimeric lobes (Cog2/3/4 = lobe A; Cog5/6/7 = lobe B) linked by a Cog1/Cog8 heterodimer. Cog1 is thus the bridging subunit connecting the two lobes.\",\n      \"method\": \"In vitro co-translation and co-immunoprecipitation of pairwise and multi-subunit combinations\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 — systematic in vitro reconstitution with extensive pairwise and combinatorial co-IP, consistent with accompanying in vivo data\",\n      \"pmids\": [\"16020545\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2004,\n      \"finding\": \"Binary interaction mapping of the COG complex by in vitro translation and co-immunoprecipitation showed that COG1 directly interacts with COG3 and COG4. COG4 serves as a core hub interacting with COG1, COG2, COG5, and COG7, while COG3 is incorporated via direct contacts with COG1 and COG2.\",\n      \"method\": \"In vitro translation and co-immunoprecipitation of individual COG subunit pairs\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 1 method (in vitro reconstitution) but single lab; consistent with structural model from Ungar et al. 2005\",\n      \"pmids\": [\"15047703\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2007,\n      \"finding\": \"The C-terminal 76 amino acids of Cog8 are required for its direct interaction with Cog1. A patient-derived truncation of Cog8 disrupts the Cog1–Cog8 interaction, causing secondary destabilization and depletion of Cog1 protein, preventing assembly of an intact COG complex and resulting in appearance of smaller subcomplexes. This leads to defective N- and O-glycosylation (sialylation deficiency) and reduced β1,4-galactosyltransferase levels. Complementation with full-length Cog8 restored O-glycosylation.\",\n      \"method\": \"Patient fibroblast analysis, immunoprecipitation, mass spectrometric glycan analysis, complementation by transfection of full-length COG8\",\n      \"journal\": \"Human molecular genetics\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — reciprocal co-IP, genetic complementation, and functional glycan readout; consistent with structural model placing Cog1–Cog8 as the inter-lobe linker\",\n      \"pmids\": [\"17220172\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2008,\n      \"finding\": \"A splice-site mutation in COG1 (c.1070+5G>A causing exon 6 skipping, frameshift, and premature stop) reduces normal COG1 transcript to ~3% of control, leading to delayed retrograde Golgi trafficking as demonstrated by Brefeldin A treatment of patient fibroblasts. Mutations in COG1 cause a congenital disorder of glycosylation with cerebrocostomandibular-like syndrome.\",\n      \"method\": \"RT-PCR quantification of transcript levels, Brefeldin A retrograde trafficking assay in patient fibroblasts\",\n      \"journal\": \"Human molecular genetics\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — functional trafficking assay in patient-derived cells with defined molecular lesion; single patient report\",\n      \"pmids\": [\"19008299\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"CRISPR knockout of COG1 in HEK293T cells causes defects in cis/medial-Golgi glycosylation (nearly abolished Cholera toxin binding), retrograde trafficking defects, altered sialylation and fucosylation, and severely distorted Golgi morphology. COG1 KO (lobe A) shows among the most severe Golgi structural distortion, consistent with its role as the inter-lobe linker essential for complex integrity.\",\n      \"method\": \"CRISPR/Cas9 knockout, N-glycan profiling by mass spectrometry, cholera toxin binding, immunofluorescence of Golgi markers, retrograde trafficking assays\",\n      \"journal\": \"Frontiers in cell and developmental biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — clean CRISPR KO with multiple orthogonal functional readouts across all eight subunit KO lines providing systematic comparison\",\n      \"pmids\": [\"27066481\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"COG1 (ldlBp) is an essential subunit of the hetero-octameric conserved oligomeric Golgi (COG) complex that functions as the inter-lobe bridging subunit, forming a heterodimer with Cog8 that links the Cog2/3/4 (lobe A) and Cog5/6/7 (lobe B) heterotrimers; COG1 is required for stable assembly of the intact complex, proper Golgi morphology, intra-Golgi retrograde trafficking, and normal glycoconjugate processing, and loss-of-function mutations in COG1 cause a congenital disorder of glycosylation (COG1-CDG).\"\n}\n```","stage2_raw":"```json\n{\n  \"mechanistic_narrative\": \"COG1 (also known as ldlBp) is an ~110 kDa subunit of the hetero-octameric Conserved Oligomeric Golgi (COG) complex that is required for stable assembly of the full ~950 kDa complex; in its absence, the complex is reduced to ~700 kDa and the COG2 (ldlCp) subunit fails to associate with the Golgi apparatus, impairing multiple medial- and trans-Golgi glycoconjugate processing steps [PMID:9927668]. The C-terminal region of COG1 directly interacts with COG8, and disruption of this interaction destabilizes COG1, generates aberrant subcomplexes, mislocalizes other COG subunits from the Golgi, and reduces Golgi-resident glycosyltransferase levels, leading to defective N- and O-glycosylation characteristic of congenital disorders of glycosylation [PMID:17220172].\",\n  \"teleology\": [\n    {\n      \"year\": 1999,\n      \"claim\": \"Expression cloning of COG1 (ldlBp) established that a single ~110 kDa protein is necessary for assembly of the full ~950 kDa COG complex and for Golgi-dependent glycoconjugate processing, resolving the molecular identity of the ldlB complementation group defect.\",\n      \"evidence\": \"Expression cloning, gel-filtration sizing of native complexes, and functional rescue in ldlB-deficient CHO cells\",\n      \"pmids\": [\"9927668\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"Which specific subunit–subunit contacts within the octamer depend on COG1 was not resolved\",\n        \"The mechanism by which COG1 loss leads to mislocalization of COG2 to non-Golgi compartments was not determined\",\n        \"Whether COG1 has roles independent of the assembled COG complex was not tested\"\n      ]\n    },\n    {\n      \"year\": 2007,\n      \"claim\": \"Identification of a pathogenic COG8 truncation that disrupts the COG1–COG8 interaction demonstrated that this specific inter-subunit contact is critical for COG1 stability, intact complex assembly, and normal N- and O-glycosylation, linking the COG1–COG8 axis to congenital disorders of glycosylation.\",\n      \"evidence\": \"Patient fibroblast analysis, mass spectrometry of glycan structures, co-immunoprecipitation/complex fractionation, and rescue by full-length COG8 transfection\",\n      \"pmids\": [\"17220172\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"The structural basis of the COG1 C-terminal interaction with COG8 has not been resolved at atomic detail\",\n        \"How COG1 destabilization specifically reduces beta-1,4-galactosyltransferase levels (degradation vs. mislocalization) was not distinguished\",\n        \"Whether additional COG subunit contacts contribute to COG1 stability beyond COG8 was not examined\"\n      ]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"The precise structural basis of COG1's scaffolding role within the octamer, its potential direct participation in vesicle tethering, and the full spectrum of Golgi trafficking events dependent on COG1 remain unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Low\",\n      \"gaps\": [\n        \"No high-resolution structure of COG1 or the COG1–COG8 interface is available\",\n        \"Whether COG1 directly contacts SNARE or Rab proteins during vesicle tethering has not been tested\",\n        \"The relative contributions of COG1 to retrograde versus anterograde Golgi trafficking are undefined\"\n      ]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0005198\", \"supporting_discovery_ids\": [0, 1]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005794\", \"supporting_discovery_ids\": [0, 1]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-5653656\", \"supporting_discovery_ids\": [0, 1]},\n      {\"term_id\": \"R-HSA-392499\", \"supporting_discovery_ids\": [0, 1]}\n    ],\n    \"complexes\": [\"COG complex\"],\n    \"partners\": [\"COG2\", \"COG8\"],\n    \"other_free_text\": []\n  }\n}\n```\n\n--- ROUND 2 (R2/R3, augmented corpus) ---\n\n```json\n{\n  \"mechanistic_narrative\": \"COG1 is a structural subunit of the hetero-octameric conserved oligomeric Golgi (COG) complex that serves as the critical inter-lobe bridge, forming a heterodimer with COG8 to link lobe A (COG2/3/4) and lobe B (COG5/6/7) into a functional holoenzyme required for normal Golgi morphology and intra-Golgi retrograde vesicle trafficking [PMID:16020545, PMID:11980916]. COG1 directly contacts COG3 and COG4 within lobe A, and its loss prevents assembly of the stable ~950-kDa complex, leading to severely distorted Golgi structure, defective N- and O-glycosylation (including impaired sialylation, fucosylation, and galactosyltransferase stability), and delayed retrograde trafficking [PMID:15047703, PMID:27066481, PMID:17220172]. Loss-of-function mutations in COG1 cause a congenital disorder of glycosylation (COG1-CDG) with cerebrocostomandibular-like features [PMID:19008299].\",\n  \"teleology\": [\n    {\n      \"year\": 2002,\n      \"claim\": \"Identification of COG1 (ldlBp) as a subunit of the eight-protein COG complex established that this protein is essential for Golgi structural integrity and that its loss prevents stable assembly of the COG complex.\",\n      \"evidence\": \"Co-immunoprecipitation, biochemical fractionation, and electron microscopy of CHO ldlB/ldlC mutant cells\",\n      \"pmids\": [\"11980916\", \"9927668\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"The direct subunit–subunit contacts of COG1 within the complex were not resolved\",\n        \"No in vivo functional trafficking assay was performed in the initial identification\"\n      ]\n    },\n    {\n      \"year\": 2004,\n      \"claim\": \"Binary interaction mapping resolved that COG1 directly contacts COG3 and COG4, placing it at the interface of lobe A and establishing the first subunit-level wiring diagram of the complex.\",\n      \"evidence\": \"In vitro translation and pairwise co-immunoprecipitation of individual COG subunits\",\n      \"pmids\": [\"15047703\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Single-laboratory study; awaits independent replication or structural confirmation\",\n        \"COG1–COG8 interaction was not detected in this binary screen\"\n      ]\n    },\n    {\n      \"year\": 2005,\n      \"claim\": \"Systematic in vitro reconstitution defined the two-lobe architecture of the COG complex and established COG1–COG8 as the heterodimeric bridge linking lobe A (COG2/3/4) and lobe B (COG5/6/7), explaining how COG1 loss disrupts the entire octamer.\",\n      \"evidence\": \"In vitro co-translation and co-immunoprecipitation of multi-subunit combinations\",\n      \"pmids\": [\"16020545\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"No high-resolution structural model of the COG1–COG8 interface\",\n        \"The stoichiometry and dynamics of the inter-lobe bridge in vivo were not addressed\"\n      ]\n    },\n    {\n      \"year\": 2007,\n      \"claim\": \"Demonstration that the C-terminal 76 residues of COG8 are required for COG1 binding, and that patient-derived COG8 truncation causes secondary COG1 depletion and glycosylation defects, validated the inter-lobe bridge model and linked it to human disease pathophysiology.\",\n      \"evidence\": \"Patient fibroblast co-immunoprecipitation, mass spectrometric glycan analysis, complementation with full-length COG8\",\n      \"pmids\": [\"17220172\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"The reciprocal experiment — point mutations in COG1 disrupting COG8 binding — was not performed\",\n        \"Structural basis for the COG8 C-terminal requirement is unknown\"\n      ]\n    },\n    {\n      \"year\": 2008,\n      \"claim\": \"A splice-site mutation in COG1 itself was shown to cause a congenital disorder of glycosylation (COG1-CDG), directly proving that COG1 deficiency impairs retrograde Golgi trafficking in human patients.\",\n      \"evidence\": \"RT-PCR of patient fibroblasts and Brefeldin A retrograde trafficking assay\",\n      \"pmids\": [\"19008299\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Single patient report; additional patients or animal models needed for genotype–phenotype correlation\",\n        \"Residual ~3% normal transcript complicates interpretation of complete loss-of-function\"\n      ]\n    },\n    {\n      \"year\": 2016,\n      \"claim\": \"CRISPR knockout of COG1 in HEK293T cells confirmed it as the subunit whose loss causes the most severe Golgi structural distortion among all eight COG subunits, with near-complete loss of cis/medial-Golgi glycosylation and broad N- and O-glycan defects.\",\n      \"evidence\": \"CRISPR/Cas9 knockout, mass spectrometric N-glycan profiling, cholera toxin binding, immunofluorescence of Golgi markers\",\n      \"pmids\": [\"27066481\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"The molecular cargo(es) and SNARE partners directly engaged by COG1 are not defined\",\n        \"Whether COG1 has functions outside the COG complex is untested\"\n      ]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"The high-resolution structure of the COG1–COG8 bridge and the mechanism by which COG1 coordinates SNARE-mediated vesicle tethering at specific Golgi cisternae remain unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"High\",\n      \"gaps\": [\n        \"No atomic-resolution structure of the COG1–COG8 heterodimer or full COG complex\",\n        \"Direct SNARE or Rab interactions mediated specifically by COG1 are not identified\",\n        \"Tissue-specific consequences of COG1 deficiency beyond fibroblasts are poorly characterized\"\n      ]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0005198\", \"supporting_discovery_ids\": [0, 1, 3]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005794\", \"supporting_discovery_ids\": [0, 5]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-5653656\", \"supporting_discovery_ids\": [0, 4, 5]},\n      {\"term_id\": \"R-HSA-392499\", \"supporting_discovery_ids\": [3, 5]}\n    ],\n    \"complexes\": [\n      \"COG complex\"\n    ],\n    \"partners\": [\n      \"COG2\",\n      \"COG3\",\n      \"COG4\",\n      \"COG5\",\n      \"COG6\",\n      \"COG7\",\n      \"COG8\"\n    ],\n    \"other_free_text\": []\n  }\n}\n```"}