Affinage

COG8

Conserved oligomeric Golgi complex subunit 8 · UniProt Q96MW5

Length
612 aa
Mass
68.4 kDa
Annotated
2026-06-09
16 papers in source corpus 5 papers cited in narrative 5 extracted findings
Cross-family judge faithfulness: 5/5 claims corpus-supported (100%)

Mechanistic narrative

Synthesis pass · prose summary of the discoveries below

COG8 is a subunit of the conserved oligomeric Golgi (COG) complex that maintains Golgi structural integrity and glycosylation fidelity (PMID:17331980). Its C-terminal 76 residues mediate a direct interaction with COG1, and a truncating mutation that abolishes this interface disrupts assembly of the intact complex, destabilizes COG1, and produces smaller COG subcomplexes, with downstream defects in N- and O-glycosylation (PMID:17220172). Complete loss of COG8 destabilizes and mislocalizes multiple other COG subunits, reduces beta-1,4-galactosyltransferase levels, impairs sialylation of N- and O-glycans, and slows brefeldin A-induced Golgi disruption, all of which are reversed by reintroduction of wild-type COG8 (PMID:17331980). Consistent with a role in retrograde membrane trafficking, COG8 knockout blocks endosome-to-trans-Golgi-network retrograde transport, trapping influenza virus and its M2 protein in early endosomes and thereby restricting infection (PMID:34935491). In yeast, the COG8 ortholog additionally cooperates with the Arl3-Arl1 GTPase cascade to direct Atg9 trafficking at the late Golgi and control selective autophagy (PMID:28627726).

Mechanistic history

Synthesis pass · year-by-year structured walk · 5 steps
  1. 2007 High

    Established that COG8 physically anchors the COG complex through a defined C-terminal COG1-binding region, explaining how its mutation causes a congenital disorder of glycosylation.

    Evidence Patient fibroblast analysis of a truncating mutation, co-IP/Western of COG subunits, glycan mass spectrometry, and rescue with full-length COG8

    PMID:17220172

    Open questions at the time
    • No atomic-resolution structure of the COG8 C-terminus–COG1 interface
    • Does not define how subcomplex accumulation relates to lobe A vs lobe B architecture
  2. 2007 High

    Showed that COG8 loss has complex-wide consequences—destabilizing and mislocalizing other subunits and impairing Golgi enzyme levels and trafficking—establishing COG8 as required for overall complex stability and Golgi function.

    Evidence Patient fibroblasts with complete COG8 loss, immunofluorescence of COG subunit localization, glycan analysis, BFA-induced Golgi disruption assay, and lentiviral complementation rescue

    PMID:17331980

    Open questions at the time
    • Mechanism linking subunit mislocalization to slowed BFA response not resolved
    • Does not identify which glycosyltransferases beyond beta-1,4-galactosyltransferase are directly affected
  3. 2011 Low

    Characterized COG8 gene architecture, showing its 3' end overlaps the adjacent PDF gene via a gained splice donor and shared polyadenylation in primates.

    Evidence Comparative genomic analysis, splice site identification, and polyadenylation signal mapping across vertebrate species

    PMID:21805148

    Open questions at the time
    • Computational/comparative analysis only, no protein-level experiment
    • Functional consequence of the COG8-PDF overlap for COG8 protein output untested
  4. 2017 Medium

    Connected the COG8 ortholog to autophagy by showing it cooperates with the Arl3-Arl1 GTPase cascade to direct Atg9 trafficking at the late Golgi.

    Evidence Yeast genetic double-deletion epistasis (arl3Δcog8Δ, arl1Δcog8Δ), aminopeptidase I maturation assay, and Atg9 fluorescence localization

    PMID:28627726

    Open questions at the time
    • Single lab, yeast ortholog—mammalian conservation of the COG8–Arl3/Arl1 axis untested
    • No direct physical interaction between Cog8 and the Arl GTPases demonstrated
  5. 2021 Medium

    Demonstrated that COG8-dependent retrograde transport is hijacked by influenza, linking COG8 loss to defective endosome-to-TGN trafficking and viral restriction.

    Evidence Genome-wide CRISPR-Cas9 screen with COG8 knockout validation in porcine cells, viral titers, EEA1/M2 colocalization, and immune gene expression analysis

    PMID:34935491

    Open questions at the time
    • Single lab; mechanism connecting COG retrograde function to early endosome viral exit not fully resolved
    • Whether enhanced immune gene expression is a direct or secondary effect of COG8 loss unknown

Open questions

Synthesis pass · forward-looking unresolved questions
  • How COG8-dependent retrograde trafficking and the COG complex are mechanistically integrated with autophagic Atg9 trafficking in mammalian cells remains unresolved.
  • No mammalian validation of the COG8–Arl3/Arl1–Atg9 autophagy axis
  • No structural model of COG8 within the assembled octameric complex

Mechanism profile

Synthesis pass · controlled-vocabulary classification · explore literature graph →
Molecular activity
GO:0060090 molecular adaptor activity 2
Localization
GO:0005794 Golgi apparatus 3
Pathway
R-HSA-5653656 Vesicle-mediated transport 2 R-HSA-9612973 Autophagy 1
Partners
COG1
Complex memberships
COG complex

Evidence

Reading pass · 5 per-paper findings extracted from the source corpus
Year Finding Method Journal Conf PMIDs
2007 The C-terminal 76 amino acids of COG8 are required for its interaction with COG1; a truncating mutation abolishing this interaction disrupts COG complex assembly, leading to loss of COG1 stability and accumulation of smaller COG subcomplexes, with consequent defects in N- and O-glycosylation. Patient fibroblast analysis with truncating mutation, mass spectrometric glycan analysis, co-immunoprecipitation/Western blot of COG subunits, rescue by transfection with full-length COG8 Human molecular genetics High 17220172
2007 Loss of COG8 protein destabilizes and mislocalizes multiple other COG complex subunits, impairs sialylation of N- and O-glycans, reduces beta-1,4-galactosyltransferase levels, and slows brefeldin A-induced Golgi disruption; lentiviral complementation with wild-type COG8 restores COG subunit localization, sialylation, and normal BFA-induced Golgi disruption. Patient fibroblast analysis (complete COG8 loss), immunofluorescence of COG subunit localization, glycan analysis, BFA-induced Golgi disruption assay, lentiviral complementation rescue Human molecular genetics High 17331980
2017 In yeast, Cog8 cooperates with the Arl3-Arl1 GTPase cascade to regulate Atg9 trafficking at the late Golgi, thereby controlling selective autophagy (the Cvt pathway); double deletion of arl3 or arl1 with cog8 causes profound defects in aminopeptidase I maturation and accumulation of Atg9 at the late Golgi under normal growth conditions. Yeast genetic double-deletion epistasis (arl3∆cog8∆ and arl1∆cog8∆), aminopeptidase I maturation assay, Atg9 localization by fluorescence microscopy Traffic (Copenhagen, Denmark) Medium 28627726
2021 COG8 knockout in porcine cells inhibits influenza virus infection by reducing colocalization of viral particles with the early endosome marker EEA1, blocking retrograde transport from the endosome to the trans-Golgi network, and causing accumulation of viral M2 protein in early endosomes; COG8 loss also enhances expression of immune-related genes. Genome-wide CRISPR-Cas9 screen followed by COG8 knockout validation; viral titer measurement, immunofluorescence colocalization of viral particles with EEA1, M2 protein localization, gene expression analysis The CRISPR journal Medium 34935491
2011 The 3′ end of COG8 overlaps with the PDF gene on the same strand; this overlap is mediated by gain of a novel splice donor site between the COG8 stop codon and the PDF initiation codon, with COG8 sharing the 3′ end via the PDF acceptor site. In primates, loss of the ancestral COG8 polyadenylation signal makes the overlap mandatory. Comparative genomic analysis, splice site identification, polyadenylation signal mapping across vertebrate species Human genetics Low 21805148

Source papers

Stage 0 corpus · 16 papers · ranked by NIH iCite citations
Year Title Journal Citations PMID
2007 A new inborn error of glycosylation due to a Cog8 deficiency reveals a critical role for the Cog1-Cog8 interaction in COG complex formation. Human molecular genetics 103 17220172
1996 An antisense oligodeoxynucleotide to the delta opioid receptor (DOR-1) inhibits morphine tolerance and acute dependence in mice. Brain research bulletin 102 8866695
2007 COG8 deficiency causes new congenital disorder of glycosylation type IIh. Human molecular genetics 96 17331980
1997 Antisense mapping DOR-1 in mice: further support for delta receptor subtypes. Brain research 34 9125445
2013 Intra-VTA deltorphin, but not DPDPE, induces place preference in ethanol-drinking rats: distinct DOR-1 and DOR-2 mechanisms control ethanol consumption and reward. Alcoholism, clinical and experimental research 19 24033469
2017 The Arl3 and Arl1 GTPases co-operate with Cog8 to regulate selective autophagy via Atg9 trafficking. Traffic (Copenhagen, Denmark) 18 28627726
2019 The first case of antenatal presentation in COG8-congenital disorder of glycosylation with a novel splice site mutation and an extended phenotype. American journal of medical genetics. Part A 14 30690882
2017 Further delineation of COG8-CDG: A case with novel compound heterozygous mutations diagnosed by targeted exome sequencing. Clinica chimica acta; international journal of clinical chemistry 10 28619360
2021 Porcine Genome-Wide CRISPR Screen Identifies the Golgi Apparatus Complex Protein COG8 as a Pivotal Regulator of Influenza Virus Infection. The CRISPR journal 9 34935491
2005 DOR-1, A novel CD10+ stromal cell line derived from progressive Langerhans cell histiocytosis of bone. Pediatric blood & cancer 7 15390308
1997 Blockade of morphine supersensitivity by an antisense oligodeoxynucleotide targeting the delta opioid receptor (DOR-1). Life sciences 6 9048971
2015 TMED6-COG8 is a novel molecular marker of TFE3 translocation renal cell carcinoma. International journal of clinical and experimental pathology 5 26045774
2010 Kappa2 opioid receptor subtype binding requires the presence of the DOR-1 gene. Frontiers in bioscience (Scholar edition) 5 20036983
2011 Successful COG8 and PDF overlap is mediated by alterations in splicing and polyadenylation signals. Human genetics 4 21805148
2023 A Rare Case of Cerebrotendinous Xanthomatosis Associated With a Mutation on COG8 Gene. Journal of investigative medicine high impact case reports 1 37083278
2024 Genome sequence of Leptolyngbya phage Dor1, a cyanophage induced from a fish pond. Microbiology resource announcements 0 39705516

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