| 2004 |
GABARAP is conjugated to phosphatidylethanolamine (PE) via a ubiquitin-like system (analogous to yeast Atg8-PE conjugation), generating a membrane-associated form-II that localizes to autophagosomal membranes; this lipidation is reversible by the deconjugase Atg4B. |
Radiolabeling with [14C]-ethanolamine, membrane fractionation, in vitro Atg4B cleavage assay |
Journal of cell science |
High |
15169837
|
| 2000 |
Human Apg7p (hATG7) acts as an E1-like activating enzyme for GABARAP, forming a thioester intermediate with GABARAP via its active-site Cys572; GABARAP co-immunoprecipitates with hApg7p and forms a stable intermediate with the C572S mutant. |
Co-immunoprecipitation, site-directed mutagenesis, cross-linking, glycerol-gradient centrifugation |
The Journal of biological chemistry |
High |
11096062
|
| 2002 |
Human Apg3p (hATG3) acts as the E2-like conjugating enzyme for GABARAP; its active-site Cys264 forms a thioester intermediate with GABARAP, and hATG3 forms an E1·E2 complex with hATG7. |
Site-directed mutagenesis, co-immunoprecipitation, E2-substrate intermediate trapping |
The Journal of biological chemistry |
High |
11825910
|
| 2003 |
A single protease, Apg4B/autophagin-1, acts as the processing and deconjugating enzyme for GABARAP (and other mammalian Atg8 homologs), identified using electrophilic activity-based probes derived from GABARAP sequence. |
Activity-based protein profiling with electrophilic probes, in vitro protease activity assay |
The Journal of biological chemistry |
High |
14530254
|
| 2005 |
GABARAP can be conjugated in vitro to both phosphatidylethanolamine (PE) and phosphatidylserine (PS) by the reconstituted hATG7/hATG3 conjugation system, but in vivo PE is the predominant target lipid. |
In vitro reconstitution with purified recombinant Atg proteins and synthetic lipid liposomes, thin-layer chromatography of endogenous conjugates |
The Journal of biological chemistry |
High |
16303767
|
| 2014 |
Lipidation of GABARAP (and LC3) by ATG3 is dependent on membrane curvature; ATG3 contains an N-terminal amphipathic helix that senses lipid-packing defects on highly curved membranes, restricting lipidation to such membranes in vitro and in vivo. |
In vitro lipidation assay on liposomes of defined curvature, amphipathic helix mutagenesis, rescue experiments in ATG3-knockout cells |
Nature cell biology |
High |
24747438
|
| 2002 |
Crystal structure of human GABARAP at 1.6 Å resolution reveals an N-terminal helical subdomain responsible for tubulin binding and a ubiquitin-like C-terminal domain containing the GABA(A) receptor binding site; GABARAP can self-associate in a head-to-tail manner promoting tubulin polymerization and receptor clustering. |
X-ray crystallography, structure-based mutagenesis |
Neuron |
High |
11779480
|
| 2002 |
Crystal structure of mammalian GABARAP at 2.0 Å resolution confirms an N-terminal basic helical region for tubulin binding and a conserved ubiquitin-like core fold; the conserved surface face mediates protein-protein interactions shared across the family. |
X-ray crystallography |
EMBO reports |
High |
11818336
|
| 2002 |
NMR solution structure of human GABARAP reveals that amino- and carboxyl-terminal ends interact with each other in solution (not seen in crystal structures), suggesting conformational dynamics that regulate GABARAP interactions. |
NMR spectroscopy |
The Journal of biological chemistry |
High |
11875056
|
| 2000 |
GABARAP binds directly to both tubulin and microtubules in a salt-sensitive (ionic interaction) manner in vitro and co-immunoprecipitates with tubulin in intact cells; the tubulin-binding domain is located at the N-terminus marked by specific basic amino acids; GABARAP also associates with microfilaments, likely via intermediary proteins. |
In vitro tubulin binding assay, co-immunoprecipitation, cytoskeletal drug treatments (taxol, nocodazole, cytochalasin D), deletion constructs and synthetic peptides |
Journal of neurochemistry |
High |
10899939
|
| 2000 |
GABARAP promotes clustering of GABA(A) receptors in QT-6 fibroblasts requiring both the tubulin-binding motif of GABARAP and the gamma2 subunit; clustered GABA(A) receptors show altered channel kinetics (higher EC50, faster deactivation, slower desensitization) compared to diffuse receptors. |
GFP-tagged receptor expression, immunofluorescence clustering assay, whole-cell electrophysiology, microtubule disruption experiments |
Proceedings of the National Academy of Sciences of the United States of America |
High |
10984509
|
| 2001 |
GABARAP is enriched in the Golgi apparatus and postsynaptic cisternae (not at inhibitory synapses), co-immunoprecipitates with GABA(A) receptors, and binds directly to NSF (N-ethylmaleimide-sensitive factor), suggesting a role in intracellular receptor transport rather than synaptic anchoring. |
Subcellular fractionation, immunoprecipitation, direct binding assay, confocal immunofluorescence |
Molecular and cellular neurosciences |
High |
11461150
|
| 2000 |
GABARAP interacts with gephyrin in biochemical assays and transfected cells; confocal analysis shows GABARAP is enriched in intracellular compartments and not at gephyrin-positive postsynaptic specializations, suggesting a role in receptor sorting/targeting rather than synaptic anchoring. |
Co-immunoprecipitation, transfected cell co-localization, gephyrin-knockout mouse analysis |
Proceedings of the National Academy of Sciences of the United States of America |
High |
10900017
|
| 2002 |
GABARAP's interaction with GABA(A) receptor is specific for gamma subunits; the interaction domain in GABARAP maps to residues 41–51, and GABARAP dimerizes using the same region (residues 36–68); a membrane-permeable peptide corresponding to the GABARAP interaction domain in gamma2 inhibits receptor clustering in living cells. |
Yeast two-hybrid quantitative assay, GST pulldown, peptide inhibition, GABA(A) receptor clustering assay in fibroblasts |
Journal of neurochemistry |
High |
11948245
|
| 2007 |
C-terminal processing of GABARAP at Gly116 (generating the lipidated form) is required for its proper subcellular distribution (away from Golgi into cytoplasmic puncta in neurons) and for its function in promoting GABA(A) receptor plasma membrane expression; the G116A mutant fails to enhance receptor surface expression. |
Site-directed mutagenesis, Western blotting with dual-tag construct, confocal microscopy, oocyte electrophysiology, surface biotinylation |
The Journal of neuroscience |
High |
17581952
|
| 2014 |
PLEKHM1 contains a GABARAP interaction motif (LIR) that mediates direct binding to autophagosomal membranes, and PLEKHM1 also directly interacts with the HOPS complex; this dual interaction is required for autophagosome-lysosome fusion, endocytic cargo degradation, and clearance of protein aggregates. |
Co-immunoprecipitation, GST pulldown, LIR mutagenesis, PLEKHM1 depletion with specific cargo degradation assays |
Molecular cell |
High |
25498145
|
| 2015 |
GABARAP (unlipidated and lipidated), but not LC3B or other ATG8 family members, specifically promotes ULK1 kinase activation in a manner dependent on the ULK1 LIR motif; GABARAP is dynamically trafficked from the pericentriolar matrix to the phagophore upon starvation, regulated by the Golgi proteins WAC and GM130. |
Protein interaction studies, GABARAP-specific KD/rescue, ULK1 kinase activity assay, live-cell imaging of GABARAP trafficking, LIR mutagenesis |
Molecular cell |
High |
26687599
|
| 2017 |
The centriolar satellite protein PCM1 directly binds GABARAP (but not LC3B) via a canonical LIR motif, stabilizing GABARAP at the pericentriolar material; loss of PCM1 leads to proteasomal degradation of GABARAP mediated by the E3 ligase Mib1, which promotes K48-linked ubiquitination of GABARAP at N-terminal residues. |
Direct binding assay, LIR mutagenesis, CRISPR/siRNA KD, proteasome inhibitor rescue, ubiquitination assay, autophagy flux measurement |
Current biology : CB |
High |
28712572
|
| 2019 |
ATL3 functions as a tubular ER-phagy receptor that specifically binds GABARAP (but not LC3) subfamily proteins via two GABARAP interaction motifs (GIMs); ATL3-GABARAP interaction is essential for starvation-induced tubular ER degradation, and HSAN I-associated ATL3 mutations (Y192C, P338R) disrupt this interaction and impair ER-phagy. |
Co-immunoprecipitation, GIM mutagenesis, ER-phagy flux assay, ATL3 KD/rescue, patient mutation analysis |
Current biology : CB |
High |
30773365
|
| 2017 |
A GABARAP interaction motif (GIM) sequence [W/F]-[V/I]-X2-V confers 11-fold selectivity for GABARAP over LC3B, as demonstrated by biophysical and structural analysis of the PLEKHM1 LIR; conversion of other LIR motifs into GIMs by introducing valine residues enhances GABARAP over LC3B binding. |
Biophysical binding measurements (ITC/SPR), crystal structure of GABARAP-GIM complex, mutagenesis of LIR/GIM positions |
EMBO reports |
High |
28655748
|
| 2019 |
PIK3C3, BECN1, and ATG14 (components of the PtdIns3K-C1 complex) each contain functional LIR motifs that interact preferentially with GABARAP and GABARAPL1 over LC3 proteins; crystal structures of these LIR motifs with GABARAP proteins reveal that variation in hydrophobic pocket 2 explains GABARAP-family specificity; ATG14 LIR mutation blocks its colocalization with LC3B and impairs mitophagy. |
Crystal structures, binding assays, LIR mutagenesis, mitophagy flux assay, colocalization studies |
Autophagy |
High |
30767700
|
| 2020 |
ATG2A contains a conserved LIR-like motif that mediates direct interaction with GABARAP proteins; ATG2A-GABARAP interaction mutants fail to form and close phagophores, blocking autophagy flux similarly to ATG2A/ATG2B double-KO cells, establishing ATG2-GABARAP interaction as essential for phagophore formation. |
Mutagenesis of ATG2A-GABARAP interaction motif, autophagy flux assay, phagophore formation imaging, double-KO comparison |
EMBO reports |
High |
32009292
|
| 2021 |
GABARAP (but not LC3) directly binds a LIR motif in the FLCN/FNIP tumor suppressor complex and mediates its sequestration to GABARAP-conjugated membrane compartments during CASM, mitophagy, and xenophagy; this disrupts FLCN/FNIP GAP activity toward RagC/D, impairing mTOR-dependent phosphorylation of TFEB and activating lysosomal biogenesis. |
Co-immunoprecipitation, LIR mutagenesis, GABARAP-specific KO, TFEB/TFE3 activity assay, RagC/D GAP assay |
Science advances |
High |
34597140
|
| 2009 |
Nix/Bnip3L directly interacts with GABARAP as demonstrated by phage display screening, in vitro binding studies, pull-down, co-immunoprecipitation, and co-localization, suggesting a direct molecular link between apoptosis and autophagy pathways. |
Phage display, in vitro binding, GST pulldown, co-immunoprecipitation, co-localization in mammalian cells |
Autophagy |
High |
19363302
|
| 2008 |
GABARAP binds to the C-terminal cytoplasmic domain of the angiotensin II type 1 receptor (AT1R) and promotes its plasma membrane expression >6-fold; siRNA knockdown of GABARAP reduces AT1R surface expression by 84%; GABARAP interaction maps to residues 32–51 and requires the C-terminal 21 aa. |
Yeast two-hybrid, GST pulldown, co-immunoprecipitation, BRET assay, siRNA knockdown, surface expression quantification |
Circulation research |
High |
18497328
|
| 2015 |
CUL3-KBTBD6/KBTBD7 ubiquitin ligase complex employs ATG8-family-interacting motifs to bind preferentially to GABARAP proteins; GABARAP-containing vesicles recruit CUL3(KBTBD6/KBTBD7) to ubiquitinate and degrade the RAC1 GEF TIAM1, thereby spatially restricting RAC1 signaling and regulating actin morphology and cell invasion. |
Interactome mass spectrometry, co-immunoprecipitation, ubiquitination assay, GABARAP KD, TIAM1 abundance measurement, RAC1 activity assay |
Molecular cell |
High |
25684205
|
| 2016 |
Lipidated GABARAP and GATE-16 (but not lipidated LC3) promote extensive membrane tethering and full membrane fusion (as shown by vesicle aggregation, lipid mixing, and aqueous content mixing without leakage) in reconstituted systems; membrane curvature (smaller vesicle diameter) and negative-curvature lipids (cardiolipin, DAG) facilitate this fusion. |
In vitro reconstituted enzymatic and chemical lipidation, vesicle tethering/fusion assays, cryo-electron microscopy |
Biophysical journal |
High |
26789764
|
| 2015 |
GABARAP directly binds to PI4K2A (phosphatidylinositol 4-kinase type 2α) and recruits it to autophagosomes; this GABARAP-PI4K2A interaction and the resulting PtdIns4P production are required for autophagosome-lysosome fusion. |
Co-immunoprecipitation, GABARAP KD, autophagosome-lysosome fusion assay |
Autophagy |
Medium |
26391226
|
| 2013 |
Mulan E3 ubiquitin ligase interacts with GABARAP via an LIR motif in its RING finger domain in complex with the E2 enzyme Ube2E3; this interaction requires both the LIR motif and Ube2E3 presence, linking Mulan to mitophagy regulation through GABARAP. |
Yeast two-hybrid (modified), co-immunoprecipitation, LIR motif analysis |
Cellular signalling |
Medium |
25224329
|
| 2021 |
GABARAP/GABARAPL1 (but not other ATG8 family members) directly bind to a previously unappreciated region in the gamma2 subunit of GABA(A)R; crystal structure of GABARAPL1-gamma2 complex reveals the molecular basis; GABARAP stabilizes GABAARs by promoting trafficking (not blocking endocytosis); phosphorylation of gamma2 differentially modulates binding to GABARAP vs. clathrin adaptor AP2; blocking GABARAP-GABAAR complex reduces GABAergic synaptic currents. |
Crystal structure, co-immunoprecipitation, electrophysiology, trafficking assays, phosphorylation mutagenesis |
Nature communications |
High |
33436612
|
| 2018 |
Ankyrin-G directly interacts with GABARAP to stabilize cell-surface GABA(A) receptors at GABAergic synapses; a knock-in mouse with the W1989R mutation abolishing ankyrin-G/GABARAP interaction shows striking reduction in forebrain GABAergic synapses, pyramidal cell hyperexcitability, and disrupted network synchronization. |
Knock-in mouse model, electrophysiology, immunofluorescence quantification of synapses |
Molecular psychiatry |
High |
30504823
|
| 2010 |
GABARAP associates with TRPV1 in HEK293 cells and DRG neurons, augments TRPV1 surface expression and clustering, attenuates voltage/capsaicin sensitivity in the presence of extracellular calcium, lengthens vanilloid-induced tachyphylaxia, and increases tubulin interaction with the TRPV1 C-terminal domain. |
Co-immunoprecipitation, surface expression quantification, electrophysiology, nocodazole cytoskeleton disruption |
FASEB journal |
Medium |
20179142
|
| 2009 |
Caspase-3 cleaves Atg4D, generating a truncated ΔN63 Atg4D with increased activity against GABARAP-L1 (but relevance to GABARAP itself is indirect); Atg4D siRNA silencing abrogates GABARAP-L1 autophagosome formation. |
In vitro caspase-3 cleavage assay, cell-based Atg4D siRNA knockdown, autophagosome formation assay |
Journal of cell science |
Medium |
19549685
|
| 2019 |
TBK1 phosphorylates GABARAP-L2 (not GABARAP itself) on surface-exposed serine residues, impeding ATG4 binding and protecting lipidated GABARAP-L2 from premature removal from nascent autophagosomes. |
In vitro kinase assay, phosphomimetic mutagenesis, liposome deconjugation assay, autophagosome formation analysis |
EMBO reports |
Medium |
31709703
|
| 2019 |
UBA5 contains an atypical LIR motif that preferentially interacts with GABARAP (not LC3) proteins; NMR/crystal structures of GABARAP-UBA5 LIR complex reveal a novel hydrophobic pocket (HP0) engaged by a conserved tryptophan N-terminal to the core LIR, with K46/K47 of GABARAP being key specificity determinants; GABARAP regulates UBA5 localization to the ER membrane in a lipidation-independent manner. |
NMR, crystal structures, ITC, swapping mutagenesis, KO cell lines, ER localization assay |
Autophagy |
High |
30990354
|
| 2017 |
GABARAP subfamily (particularly GATE-16/GABARAPL2) but not LC3 proteins are required for IFN-γ-mediated clearance of vacuolar pathogens (Toxoplasma); GATE-16 specifically associates with the small GTPase ARF1 to mediate uniform cytosolic distribution of interferon-inducible GTPases (IFN-GTPases); loss of GABARAPs reduces ARF1 activation, causing IFN-GTPase aggregation. |
GABARAP-family-specific KO cells and mice, Toxoplasma clearance assay, ARF1 co-immunoprecipitation, GTPase activation assay |
Nature immunology |
High |
28604719
|
| 2007 |
Calreticulin is a high-affinity ligand of GABARAP (Kd = 64 nM) identified by phage display; the interaction was confirmed by pull-down from brain lysate and co-localization in N2a cells; crystal structure of GABARAP in complex with the calreticulin binding epitope was determined. |
Phage display, SPR/biophysical binding, GST pulldown, co-localization, crystal structure of complex |
The FEBS journal |
High |
17916189 19154346
|
| 2013 |
GABARAP deficiency in macrophages leads to inefficient clearance of damaged mitochondria, resulting in elevated mitochondrial ROS and cytosolic mitochondrial DNA release, which enhances NLRP3 inflammasome activation (increased caspase-1, IL-1β, IL-18); GABARAP-deficient mice show higher mortality in sepsis models. |
GABARAP KO mouse, mitophagy assay, mitochondrial ROS measurement, inflammasome activation assay (caspase-1 processing, cytokine secretion) |
Journal of immunology |
High |
23427251
|
| 2006 |
Lysosomal turnover of endogenous GABARAP-phospholipid conjugate (GABARAP-PL) is activated during differentiation of C2C12 cells to myotubes independently of mTOR kinase inactivation (unlike starvation-induced autophagy); little GABARAP-PL accumulates during canonical starvation-induced autophagy in most tissues. |
Lysosomal protease inhibitor accumulation assay, S6 kinase phosphorylation as mTOR readout, tissue-specific endogenous GABARAP-PL analysis |
Autophagy |
Medium |
16874098
|
| 2013 |
Bcl-2 directly binds GABARAP via a three-residue segment (EWD) adjacent to the BH4 region, anchored to one hydrophobic pocket of GABARAP; Bcl-2 overexpression inhibits GABARAP lipidation, linking Bcl-2's autophagy-inhibitory function to direct competition with the lipid conjugation machinery. |
NMR chemical shift mapping, mutagenesis, pull-down, GABARAP lipidation assay |
The Journal of biological chemistry |
High |
24240096
|
| 2025 |
STING activation triggers LRRK2 lysosomal recruitment and kinase activation via the CASM (conjugation of ATG8 to single membranes) pathway; LRRK2 activation is highly dependent on interactions with GABARAP (not other ATG8 family members); multiple lysosome-perturbing stimuli converge on CASM-GABARAP to control LRRK2 kinase activity. |
STING agonist treatment, GABARAP-specific KO/interaction mutants, LRRK2 lysosome recruitment imaging, LRRK2 kinase activity assay (Rab phosphorylation) |
The Journal of cell biology |
High |
39812709
|
| 2019 |
ATG4 isoforms (ATG4A, ATG4C, ATG4D) contribute redundantly to priming activity that enables lipidation of endogenous GABARAPL1 on autophagic structures; ATG4B is the dominant but not sole isoform processing GABARAP family proteins; pre-primed LC3B can rescue autophagic degradation without ATG4-mediated delipidation. |
CRISPR-Cas9 KO, siRNA depletion, processing assay, autophagy flux measurement (SQSTM1 degradation), correlative light and electron microscopy |
Autophagy |
High |
30661429
|
| 2014 |
FLCN directly interacts with GABARAP; the FLCN-GABARAP association is modulated by FNIP1/FNIP2 and further regulated by ULK1 phosphorylation of FLCN at Ser406, Ser537, and Ser542. |
Co-immunoprecipitation, ULK1 overexpression phosphorylation mapping, autophagy flux assay |
Autophagy |
Medium |
25126726
|
| 2012 |
MAPK15/ERK8 interacts with GABARAP (and LC3B, GABARAPL1) via a conserved LIR motif; MAPK15 localizes to autophagic compartments and stimulates ATG8-family protein lipidation, autophagosome formation, and SQSTM1 degradation in a kinase-dependent fashion. |
Co-immunoprecipitation, LIR mutagenesis, autophagosome formation assay, lipidation assay, SQSTM1 degradation assay |
Autophagy |
Medium |
22948227
|
| 2017 |
HIV-1 Nef binds directly and specifically to all GABARAP family members (but not LC3 family members) via two surface-exposed hydrophobic pockets (involving S53 and F62 of GABARAP); GABARAP knockdown significantly reduces Nef plasma membrane localization. |
Pulldown with purified recombinant proteins, co-immunoprecipitation, NMR chemical shift mapping, site-directed mutagenesis, siRNA knockdown, live-cell fluorescence microscopy |
Scientific reports |
High |
28729737
|
| 2002 |
GABARAP self-associates and dimerizes at physiological salt concentrations; the dimerization domain maps to residues 41–51 (the same region that binds the GABA(A) receptor gamma2 subunit), as shown by synthetic peptide inhibition of GST pulldown. |
GST pulldown, synthetic peptide competition, deletion constructs |
Neuropharmacology |
Medium |
12367594
|
| 2006 |
Co-expression of GABARAP with GABA(A) receptors increases single-channel conductance to ≥40 pS (vs. 30 pS control) and mean open time; the increased conductance is GABA concentration-dependent, demonstrating that GABARAP-mediated trafficking influences ion channel gating properties. |
Outside-out patch clamp electrophysiology of transiently transfected cells |
The Journal of biological chemistry |
Medium |
16954214
|
| 2002 |
GABARAP interacts with transferrin receptor (TfR) cytoplasmic domain via its YTRF internalization motif, as shown by yeast two-hybrid, in vitro binding with purified proteins, and co-immunoprecipitation from HeLa cells; GABARAP-GFP localizes to perinuclear vesicles, suggesting a general role in vesicle trafficking beyond neurons. |
Yeast two-hybrid, in vitro binding assay, co-immunoprecipitation, GFP chimera localization |
FEBS letters |
Medium |
11997026
|