Affinage

ARFGAP2

ADP-ribosylation factor GTPase-activating protein 2 · UniProt Q8N6H7

Length
521 aa
Mass
56.7 kDa
Annotated
2026-04-28
31 papers in source corpus 12 papers cited in narrative 12 extracted findings

Mechanistic narrative

Synthesis pass · prose summary of the discoveries below

ARFGAP2 is a coatomer-dependent ArfGAP that catalyzes GTP hydrolysis on Arf1 to regulate COPI vesicle coat assembly and Golgi-to-ER retrograde transport. Rather than binding membranes directly, ARFGAP2 is recruited to the Golgi through interactions with the γ-COP appendage domain platform subdomain and the CM4 adaptin-like subcomplex of coatomer, and its full catalytic activation requires the intact heptameric coatomer (CM3+CM4) (PMID:14690497, PMID:19109418, PMID:22375848). Combined depletion of ARFGAP2 and ARFGAP3 causes Golgi unstacking, disrupted COPI coat lattice formation, and blocked retrograde transport that phenocopies β-COP loss (PMID:19299515, PMID:20858901). ARFGAP2 also functions as a cell-type-specific regulator of STING proton channel activity at the Golgi, where its deletion in hematopoietic and endothelial cells abolishes STING-driven cytokine secretion and ameliorates autoinflammatory disease in a SAVI mouse model (PMID:39947179).

Mechanistic history

Synthesis pass · year-by-year structured walk · 8 steps
  1. 2004 High

    Identifying how ARFGAP2 physically engages coatomer established the structural basis for its recruitment: the γ-COP appendage domain platform subdomain provides a specific binding site, paralleling the yeast Glo3p–Sec21p interaction.

    Evidence Crystal structure of γ-COP appendage domain with binding assays and mutagenesis

    PMID:14690497

    Open questions at the time
    • Binding interface not resolved at atomic level for full-length ARFGAP2
    • Role of other coatomer subunits in recruitment not yet addressed
  2. 2007 High

    Demonstrating that ARFGAP2 co-localizes with coatomer, associates with COPI vesicles, and is functionally required for Golgi-to-ER retrograde transport established it as a bona fide component of the COPI machinery.

    Evidence Immunofluorescence, in vitro COPI vesicle generation, dominant-negative truncation mutant blocking cholera toxin transport, siRNA knockdown

    PMID:17760859

    Open questions at the time
    • Relative contributions of ARFGAP2 vs. ARFGAP3 not disentangled
    • Cargo specificity of ARFGAP2-dependent transport unknown
  3. 2008 High

    Reconstitution experiments resolved a key mechanistic question — whether ARFGAP2 senses membrane curvature like ARFGAP1 — by showing it does not bind membranes directly but instead is recruited via coatomer, which also stimulates its GAP activity to levels comparable to or exceeding ARFGAP1.

    Evidence In vitro membrane binding assays and reconstituted GAP activity assays with and without coatomer; domain dissection identifying central basic stretch as coatomer-interaction motif

    PMID:19015319 PMID:19109418

    Open questions at the time
    • Structural basis of coatomer-stimulated catalysis unresolved
    • Whether ARFGAP2 and ARFGAP3 are truly redundant or have distinct regulatory inputs
  4. 2009 High

    Triple knockdown of all three ArfGAPs showed that complete loss of ArfGAP activity increases Arf-GTP levels and phenocopies β-COP depletion, proving that ArfGAPs collectively are essential for COPI coat cycling rather than merely accessory regulators.

    Evidence Triple siRNA knockdown with ARF-GTP pull-down, immunofluorescence, electron microscopy

    PMID:19299515

    Open questions at the time
    • Individual contribution of ARFGAP2 alone not isolated in this triple-KD approach
    • Whether phenotype reflects coat disassembly failure or assembly failure not resolved
  5. 2010 High

    Live-cell imaging and EM ultrastructure after selective knockdowns revealed that ARFGAP2/3, not ARFGAP1, are the primary ArfGAPs tracking coatomer dynamics and maintaining COPI coat lattice integrity and Golgi stack architecture.

    Evidence Live cell imaging of coatomer dynamics, siRNA knockdown of ARFGAP2/3, electron microscopy of Golgi ultrastructure

    PMID:20858901

    Open questions at the time
    • Whether ARFGAP2 and ARFGAP3 have non-overlapping functions in coat assembly not determined
    • Mechanism by which coat lattice integrity maintains Golgi stacking unclear
  6. 2012 High

    Reconstitution with recombinant coatomer subcomplexes dissected the recruitment-versus-activation problem: CM4 recruits ARFGAP2 via the γ1-COP appendage hydrophobic pocket, but catalytic stimulation requires both CM3 and CM4, establishing a two-step activation model analogous to COPII Sec13/31 cage-stimulated Sec23 GAP activity.

    Evidence Recombinant coatomer subcomplex reconstitution, membrane recruitment assay, in vitro GAP activity assay

    PMID:22375848

    Open questions at the time
    • Whether CM3 acts allosterically or repositions Arf1 for catalysis not determined
    • No high-resolution structure of ARFGAP2 in complex with coatomer
  7. 2019 Medium

    Work on the yeast orthologue Glo3 revealed that AMPK-family kinase Snf1 phosphorylates the region critical for Glo3's GAP function, providing the first evidence that metabolic signaling directly tunes ArfGAP2/3-mediated COPI coat dynamics.

    Evidence Genetic dissection, in vitro kinase assay, COPI coat stability assays in yeast

    PMID:31965

    Open questions at the time
    • Whether mammalian AMPK similarly phosphorylates ARFGAP2 not tested
    • Physiological conditions under which this phospho-regulation operates in vivo unknown
    • Single study in yeast orthologue without mammalian validation
  8. 2025 High

    Conditional knockout studies uncovered an unexpected non-canonical function: ARFGAP2 is required for STING proton channel activity at the Golgi and controls STING-mediated cytokine secretion in hematopoietic and endothelial cells, linking COPI machinery to innate immune signaling and autoinflammatory disease.

    Evidence Conditional knockout mice, proton efflux measurements, cytokine assays, in vivo SAVI autoinflammatory disease model

    PMID:39947179

    Open questions at the time
    • Molecular mechanism by which ARFGAP2 regulates STING proton channel gating unknown
    • Whether this function depends on ARFGAP2 catalytic GAP activity or a scaffolding role not resolved
    • Whether ARFGAP3 can compensate in non-hematopoietic cell types not addressed

Open questions

Synthesis pass · forward-looking unresolved questions
  • No high-resolution structure of ARFGAP2 in complex with coatomer or STING exists, and the mechanism by which ARFGAP2 regulates STING proton channel activity — whether via direct interaction, Arf1-dependent membrane remodeling, or another route — remains unresolved.
  • No atomic-resolution structure of ARFGAP2–coatomer complex
  • Mechanism of ARFGAP2 regulation of STING proton channel activity unknown
  • Post-translational regulation of mammalian ARFGAP2 (e.g., by AMPK) not established

Mechanism profile

Synthesis pass · controlled-vocabulary classification · explore literature graph →
Molecular activity
GO:0003924 GTPase activity 4 GO:0098772 molecular function regulator activity 4
Localization
GO:0005794 Golgi apparatus 4 GO:0031410 cytoplasmic vesicle 2
Pathway
R-HSA-5653656 Vesicle-mediated transport 4 R-HSA-9609507 Protein localization 3 R-HSA-168256 Immune System 1
Partners
ARF1ARFGAP3COPACOPB1COPG1SCGNSTING1
Complex memberships
COPI coat

Evidence

Reading pass · 12 per-paper findings extracted from the source corpus
Year Finding Method Journal Conf PMIDs
2004 ARFGAP2 binds to the platform subdomain of the γ-COP appendage domain, identified as the mammalian orthologue of yeast Glo3p interacting with the gamma-COP appendage at a single protein-protein interaction site. Crystal structure of γ-COP appendage domain combined with binding assays; yeast Glo3p interaction mapped by mutagenesis of Sec21p Traffic High 14690497
2007 ARFGAP2 and ARFGAP3 are identified as human orthologues of yeast Glo3p; they co-localize with coatomer at the Golgi and peripheral punctate structures, are associated with COP-I-coated vesicles generated in vitro, and a truncated mutant lacking the zinc finger domain (ΔN-ARFGAP2) that directly binds coatomer acts as a dominant negative to inhibit COP-I-dependent Golgi-to-ER transport of cholera toxin. Immunofluorescence co-localization, in vitro COP-I vesicle generation, direct binding assay with truncated mutant, in vivo transport assay with dominant-negative, siRNA knockdown Traffic High 17760859
2008 ARFGAP2 and ARFGAP3 do not bind directly to membranes but are recruited to membranes via interactions with coatomer; in the presence of coatomer, their GAP activities are comparable to or higher than ARFGAP1, demonstrating that coatomer stimulates their catalytic GTP hydrolysis on Arf1. In vitro membrane binding assays, GAP activity assays with and without coatomer, reconstitution The Journal of cell biology High 19015319
2008 Golgi localization of ARFGAP2 depends on coatomer; a central basic stretch in ARFGAP2/3 interacts directly with coatomer, which is essential for their catalytic activity on Arf1-GTP, while a carboxy-amphipathic motif interacts with lipid membranes but plays a minor role in regulation. Reporter fusion localization assays, in vitro binding assays, in vitro GAP activity assays with coatomer Molecular biology of the cell High 19109418
2009 Simultaneous knockdown of ARFGAP1, ARFGAP2, and ARFGAP3 increases GTP-bound ARF levels and blocks Golgi-to-ER retrograde transport, causing accumulation of ERGIC-53, β-COP, and GM130 in ERGIC and formation of vacuolar structures with COPI at their rims, phenocopying β-COP depletion. Triple siRNA knockdown, immunofluorescence, electron microscopy, ARF-GTP pull-down assay The Journal of biological chemistry High 19299515
2009 In yeast, the ArfGAP2/3 orthologue Glo3 contains a BoCCS region in its central domain that interacts with coatomer, SNAREs, and cargo; the GAP domain together with this BoCCS region is necessary and sufficient for all vital Glo3 functions in COPI vesicle generation. Domain truncation analysis, genetic complementation in yeast, interaction assays Traffic High 19602196
2010 ARFGAP2 and ARFGAP3 follow coatomer dynamics during vesicle budding in vivo more closely than ARFGAP1; knockdown of both ARFGAP2 and ARFGAP3 causes Golgi unstacking, cisternal shortening, and prevents proper assembly of the COPI coat lattice, a phenotype not seen with ARFGAP1 knockdown alone. Live cell imaging, siRNA knockdown, electron microscopy, COPI coat assembly assay in living cells The Journal of biological chemistry High 20858901
2011 ARFGAP2 interacts with secretagogin, a calcium-binding protein, with high affinity (equilibrium dissociation constants 100 pM–10 nM range), suggesting a role in Ca2+-regulated vesicle trafficking. Protein array screening, surface plasmon resonance, GST pulldown assay Molecular bioSystems Medium 21528130
2012 Within coatomer, the CM4 (adaptin-like tetrameric) subcomplex recruits ARFGAP2 via a hydrophobic pocket on the appendage domain of γ1-COP; CM4 is recruited to membranes through Arf1 and can subsequently recruit ARFGAP2, while neither CM3 nor CM4 alone stimulates ARFGAP2 activity — stimulation requires both subcomplexes, with CM3 playing a role analogous to the COPII cage in stimulating catalysis. Recombinant coatomer subcomplex reconstitution, membrane recruitment assay, in vitro GAP activity assay Traffic High 22375848
2015 GIV/Girdin activates Gαi at the Golgi, and this pathway regulates the cyclical activation of Arf1 by interacting with ArfGAP2/3; GIV coordinates with ArfGAP2/3 and β-COP to regulate Arf1-GTP levels and protein transport along the secretory pathway. Co-immunoprecipitation, Arf1-GTP level measurement, secretory pathway transport assay, selective pathway inhibition Developmental cell Medium 25865347
2019 In yeast, Glo3 (ARFGAP2/3 orthologue) specifically triggers Arf1 GTP hydrolysis impinging on COPI coat stability, occupying a distinct Arf1 pocket in the COPI coat; the Snf1 kinase complex (yeast AMPK homologue) phosphorylates the region of Glo3 crucial for this effect, thereby regulating its function in the COPI-vesicle cycle. Genetic dissection, in vitro kinase assay, COPI coat stability assays, structural modeling with functional validation Journal of cell science Medium 31331965
2025 ARFGAP2 is a cell-type-specific dual regulator of STING-mediated proton efflux and signaling at the Golgi; deletion of ARFGAP2 in hematopoietic and endothelial cells markedly reduces STING-mediated cytokine and chemokine secretion, immune cell activation, and autoinflammatory pathology in SAVI mice, establishing ARFGAP2 as a required component for STING proton channel activity and non-transcriptional regulation of Golgi cargo trafficking. Conditional knockout mice, proton efflux measurements, cytokine secretion assays, in vivo SAVI disease model Cell High 39947179

Source papers

Stage 0 corpus · 31 papers · ranked by NIH iCite citations
Year Title Journal Citations PMID
2001 The autonomic higher order processing nuclei of the lower brain stem are among the early targets of the Alzheimer's disease-related cytoskeletal pathology. Acta neuropathologica 76 11515783
2004 Gamma-COP appendage domain - structure and function. Traffic (Copenhagen, Denmark) 70 14690497
2008 Differential roles of ArfGAP1, ArfGAP2, and ArfGAP3 in COPI trafficking. The Journal of cell biology 61 19015319
2007 Two human ARFGAPs associated with COP-I-coated vesicles. Traffic (Copenhagen, Denmark) 50 17760859
2008 Discrete determinants in ArfGAP2/3 conferring Golgi localization and regulation by the COPI coat. Molecular biology of the cell 40 19109418
2015 Activation of Gαi at the Golgi by GIV/Girdin imposes finiteness in Arf1 signaling. Developmental cell 36 25865347
2011 Identification of a high-affinity network of secretagogin-binding proteins involved in vesicle secretion. Molecular bioSystems 35 21528130
2009 Three homologous ArfGAPs participate in coat protein I-mediated transport. The Journal of biological chemistry 33 19299515
2009 The GAP domain and the SNARE, coatomer and cargo interaction region of the ArfGAP2/3 Glo3 are sufficient for Glo3 function. Traffic (Copenhagen, Denmark) 29 19602196
2001 Anatomic relationships of the human nucleus paragigantocellularis lateralis: a DiI labeling study. Autonomic neuroscience : basic & clinical 28 11474639
2013 ArfGAP3 regulates the transport of cation-independent mannose 6-phosphate receptor in the post-Golgi compartment. Current biology : CB 25 24076238
2001 Molecular cloning and characterization of a zinc finger protein involved in Id-1-stimulated mammary epithelial cell growth. The Journal of biological chemistry 25 11278321
2010 ARFGAP2 and ARFGAP3 are essential for COPI coat assembly on the Golgi membrane of living cells. The Journal of biological chemistry 24 20858901
2013 Selection of new appropriate reference genes for RT-qPCR analysis via transcriptome sequencing of cynomolgus monkeys (Macaca fascicularis). PloS one 21 23613744
2001 Alpha2 receptor binding in the medulla oblongata in the sudden infant death syndrome. Journal of neuropathology and experimental neurology 18 11273002
2019 Dissection of GTPase-activating proteins reveals functional asymmetry in the COPI coat of budding yeast. Journal of cell science 15 31331965
2025 ArfGAP2 promotes STING proton channel activity, cytokine transit, and autoinflammation. Cell 13 39947179
2015 The ArfGAP2/3 Glo3 and ergosterol collaborate in transport of a subset of cargoes. Biology open 9 25964658
2012 Distinct role of subcomplexes of the COPI coat in the regulation of ArfGAP2 activity. Traffic (Copenhagen, Denmark) 9 22375848
1978 Genetic control of immunologic unresponsiveness to adjuvant-free solutions of beta-D-galactosidase. I. Inheritance of the Ir-Z1 and ir-Z2 loci in mice. Journal of immunology (Baltimore, Md. : 1950) 9 96178
2023 MIF Variant rs755622 Is Associated with Severe Crohn's Disease and Better Response to Anti-TNF Adalimumab Therapy. Genes 8 36833379
2021 ArfGAP1 acts as a GTPase-activating protein for human ADP-ribosylation factor-like 1 protein. FASEB journal : official publication of the Federation of American Societies for Experimental Biology 8 33715220
2018 The Arf-GDP-regulated recruitment of GBF1 to Golgi membranes requires domains HDS1 and HDS2 and a Golgi-localized protein receptor. Journal of cell science 8 29507113
2022 ArfGAP3 regulates vesicle transport and glucose uptake in myoblasts. Cellular signalling 7 36476390
2016 Integration of genome-wide association and extant brain expression QTL identifies candidate genes influencing prepulse inhibition in inbred F1 mice. Genes, brain, and behavior 6 26482417
2011 Protein networks involved in vesicle fusion, transport, and storage revealed by array-based proteomics. Methods in molecular biology (Clifton, N.J.) 6 21877276
2023 DeepGenePrior: A deep learning model for prioritizing genes affected by copy number variants. PLoS computational biology 3 37486921
2016 DASAF: An R Package for Deep Sequencing-Based Detection of Fetal Autosomal Abnormalities from Maternal Cell-Free DNA. BioMed research international 3 27437397
2025 Rac1 Suppression by the Focal Adhesion Protein GIT ArfGAP2 and Podocyte Protection. Journal of the American Society of Nephrology : JASN 2 40019803
2024 Label-free quantitative proteomics reveals the mechanisms of Aurora kinase B in renal cell carcinoma. SAGE open medicine 2 38516642
2025 Targets and Potential Mechanism of Chondroitin Sulfate A-selenium Nanoparticle on Kashin-Beck Disease Chondrocytes. Biological trace element research 0 40138104