| 2007 |
GGA3 is required for lysosomal degradation of BACE1; caspase-3 cleaves GGA3 during apoptosis/ischemia, reducing GGA3 levels and thereby stabilizing BACE1 post-translationally, leading to elevated BACE1 levels and beta-secretase activity. RNAi silencing of GGA3 elevated BACE1 and Abeta levels. |
RNAi knockdown, caspase-3 cleavage assays, mouse cerebral ischemia model, AD brain samples |
Neuron |
High |
17553422
|
| 2004 |
GGA3 localizes to both the TGN and early endosomes. RNAi of GGA3 causes accumulation of the cation-independent mannose 6-phosphate receptor (CI-MPR) and internalized EGF in enlarged early endosomes, impairing EGF degradation and EGFR sorting to late endosomes. The VHS and GAT domains of GGA3 bind ubiquitin and interact with TSG101, a component of the ubiquitin-dependent sorting machinery. |
RNAi knockdown, protein interaction assays (pulldown/co-IP), subcellular fractionation, fluorescence microscopy |
Nature cell biology |
High |
15039775
|
| 2003 |
Crystal structure of the GAE domain of human GGA3 in complex with a peptide from accessory protein Rabaptin-5 (DFGPLV sequence) resolved at 2.2 Å; leucine and valine residues of the peptide engage two contiguous shallow hydrophobic depressions and the anchoring phenylalanine is buried in a deep pocket formed by conserved arginine residues, an alanine, and a proline. |
X-ray crystallography at 2.2 Å resolution |
Nature structural biology |
High |
12858162
|
| 2006 |
PACS-1 links GGA3 to CK2, forming a multimeric complex required for CI-MPR sorting. PACS-1-bound CK2 phosphorylates GGA3, releasing GGA3 from CI-MPR and early endosomes; CK2 also phosphorylates PACS-1 Ser278 to promote PACS-1 binding to CI-MPR for TGN retrieval. This defines a CK2-activated phosphorylation cascade coordinating GGA3-mediated TGN export and PACS-1-mediated endosome-to-TGN retrieval of CI-MPR. |
Co-immunoprecipitation, in vitro kinase assays, RNAi, subcellular fractionation |
The EMBO journal |
High |
16977309
|
| 2005 |
Crystal structure of human GGA3 C-GAT domain in complex with ubiquitin reveals that a hydrophobic patch on C-GAT helices α1 and α2 binds the hydrophobic Ile44 surface of ubiquitin. Two distinct orientations of ubiquitin Arg42 give rise to two different binding modes. A second hydrophobic binding site on C-GAT helices α2 and α3, opposite to the first, also binds ubiquitin weakly. |
X-ray crystallography, NMR, biochemical binding assays |
Genes to cells |
High |
15966896
|
| 2010 |
GGA3 regulates BACE1 levels via the ubiquitin sorting machinery rather than solely via VHS domain–DXXLL motif interaction. BACE1 is ubiquitinated at lysine 501 (monoubiquitinated and Lys-63-linked polyubiquitinated). A GGA3 mutant with reduced ubiquitin-binding ability (GGA3-L276A) failed to regulate BACE1 levels, whereas mutations abrogating VHS–DXXLL binding (GGA3-N91A or BACE1-L499A/L500A) did not prevent GGA3-mediated regulation of BACE1. |
Mutagenesis, RNAi rescue/overexpression, ubiquitination assays, Western blotting in H4 neuroglioma cells |
The Journal of biological chemistry |
High |
20484053
|
| 2005 |
EGF receptor activation induces transient phosphorylation of GGA3 on Ser368 in the hinge segment, dependent on constitutive phosphorylation of Ser372. Phosphorylation requires neither EGF receptor internalization nor GGA3 membrane association, and can be blocked by MEK and PI3K pathway inhibitors. Phosphomimic mutations (S368D/S372D) decrease GGA3 association with organellar membranes. |
Phosphorylation mapping, site-directed mutagenesis, kinase inhibitor treatment, hydrodynamic radius analysis, membrane fractionation |
Molecular and cellular biology |
High |
16135791
|
| 2006 |
hVPS18, a RING-H2 ubiquitin ligase, monoubiquitylates GGA3 at lysine 258 in the GAT domain. Ubiquitin binding to the GAT domain is a prerequisite for GGA3 ubiquitylation by hVPS18. Once ubiquitylated, the GAT domain can no longer bind ubiquitin, indicating that hVPS18-mediated ubiquitylation negatively regulates GGA3's ubiquitin-binding ability. |
In vitro ubiquitylation assays, mutagenesis (K258 and ubiquitin mutations), binding assays |
Biochemical and biophysical research communications |
High |
16996030
|
| 2011 |
GGA3 interacts selectively with the Met/HGF receptor tyrosine kinase upon stimulation and sorts Met for recycling from a Rab4 endosomal subdomain in association with 'gyrating' clathrin. GGA3 loss abolishes Met recycling, redirects Met toward degradation, and attenuates ERK activation and cell migration. Met recycling requires GGA3 interaction with Arf6 and association with the Crk adaptor. |
Co-immunoprecipitation, RNAi knockdown, recycling assays, live imaging of clathrin, ERK activation assays, migration assays |
Developmental cell |
High |
21664574
|
| 2012 |
GGA3 is depleted while BACE1 increases acutely (48 h) after traumatic brain injury (TBI) in mice. BACE1 levels are increased in GGA3 null mouse brains in vivo. GGA1, a GGA3 homolog, is a novel caspase-3 substrate also depleted at 48 h post-TBI; GGA1 silencing potentiates BACE1 elevation caused by GGA3 deletion in neurons, indicating synergistic regulation. In the subacute phase (7 d), efficient BACE1 disposal depends solely on GGA3, not GGA1. |
Mouse TBI model, GGA3 knockout mice, GGA1/GGA3 double knockdown in neurons, Western blotting |
The Journal of neuroscience |
High |
22836275
|
| 2014 |
RNF11 contains acidic-cluster dileucine (Ac-LL) motifs recognized by GGA VHS domains, directing RNF11 sorting at the TGN and internalization from the plasma membrane. RNF11 recruits the E3 ligase Itch to drive ubiquitination of GGA3, with catalytically inactive RNF11 causing GGA3 hyperubiquitination. Itch regulates endogenous GGA3 stability; GGA3 levels increase in cells knocked down for Itch. |
Co-immunoprecipitation, ubiquitination assays, RNAi, domain mapping, confocal microscopy |
Oncogene |
Medium |
25195858
|
| 2015 |
GGA3 directly interacts with the TrkA cytoplasmic tail through an internal DXXLL motif and mediates TrkA recycling to the plasma membrane in an Arf6-dependent manner. GGA3 depletion delays TrkA recycling, accelerates TrkA degradation, attenuates sustained NGF-induced Akt activation, and reduces cell survival. |
Co-immunoprecipitation, RNAi knockdown, recycling assays, Akt phosphorylation assays, cell survival assays |
Molecular biology of the cell |
Medium |
26446845
|
| 2016 |
GGA3 knockdown reduces cell surface and total levels of α2, α5, and β1 integrin subunits, promotes their lysosomal degradation, inhibits cell spreading, reduces focal adhesion number, and impairs cell migration. Integrin trafficking and maintenance depend on the integrity of GGA3's Arf-binding site. GGA3 depletion mislocalizes sorting nexin 17 (SNX17) to enlarged late endosomes, implicating GGA3 in SNX17-dependent integrin recycling. |
RNAi knockdown, flow cytometry (surface levels), confocal microscopy, migration assays, focal adhesion staining |
Traffic |
Medium |
26935970
|
| 2016 |
GGA3 physically interacts with α2B-adrenergic receptor (α2B-AR) via the triple Arg motif in the third intracellular loop of the receptor and the acidic EDWE motif in the VHS domain of GGA3. GGA3 knockdown arrests newly synthesized α2B-AR in the TGN, inhibiting its cell surface export and attenuating α2B-AR-mediated ERK1/2 activation and cAMP inhibition. α2A-AR does not interact with GGA3 and is unaffected by GGA3 knockdown. |
Co-immunoprecipitation, domain mutagenesis, inducible surface expression system, RNAi knockdown, ERK/cAMP signaling assays |
Molecular and cellular biology |
Medium |
26811329
|
| 2019 |
GGA3 mediates GDNF-dependent slow recycling of the RET51 receptor tyrosine kinase isoform to the plasma membrane. GRB2 associates with RET51 C-terminal sequences, facilitating recruitment of active ARF6 and GGA3 interaction. GGA3 or ARF6 depletion reduces RET51 recycling and accelerates RET51 degradation, attenuates AKT activation, and impairs RET51-dependent cell motility, migration, and invasion. |
Co-immunoprecipitation, RNAi knockdown, recycling assays, AKT phosphorylation assays, migration/invasion assays |
Oncogene |
Medium |
31645646
|
| 2020 |
GGA3 regulates recycling of the prostaglandin D2 receptor DP1 through a Rab4-dependent mechanism. GGA3 interacts endogenously with DP1 (co-IP confirmed), with the interaction promoted by agonist stimulation. GGA3 interacts with intracellular loop 2 and C-terminus of DP1 via its VHS domain. An ARF-binding-deficient GGA3 mutant (N194A) still supports DP1 recycling. GGA3 also interacts with L-PGDS (co-IP and in vitro with purified proteins), and both GGA3 and L-PGDS function interdependently in DP1 recycling. GGA3 knockdown inhibits ERK1/2 activation following DP1 stimulation. |
Co-immunoprecipitation (endogenous), pulldown with purified recombinant proteins, confocal microscopy, domain mutagenesis, RNAi, recycling assays, ERK signaling assays |
Cellular signalling |
Medium |
32334026
|
| 2003 |
GGA3 exists as two splice variants (GGA3-S and GGA3-L). By immunofluorescence microscopy, GGA1 and GGA3 show slightly different localization patterns at both the TGN and peripheral region. Overexpression of the dominant-negative VHS-GAT domain of GGA1 or GGA3-L redistributes TGN-associated GGA1 to the cytoplasm but does not affect GGA3 distribution. |
Western blotting, double immunofluorescence microscopy, dominant-negative overexpression |
Biochemical and biophysical research communications |
Low |
12810073
|
| 2020 |
GGA3 loss of function (genetic deletion or a rare AD-associated variant) disrupts axonal trafficking of BACE1, causing its accumulation in axonal swellings in cultured neurons and in vivo. Pharmacological BACE1 inhibition ameliorates axonal trafficking and reduces axonal dystrophies in Gga3-null neurons in vitro and in vivo. GGA3 deletion exacerbates axonal dystrophies in a mouse AD model before Aβ deposition. |
GGA3 knockout mice, primary neuron culture, BACE1 pharmacological inhibition, in vivo imaging/histology |
Science translational medicine |
High |
33208500
|
| 2016 |
GGA3 deletion in mice results in increased phasic GABAergic inhibition and decreased tonic inhibition in dentate gyrus granule cells, along with increased number of inhibitory synapses in the dentate gyrus, indicating a role for GGA3 in regulating GABAergic synaptic transmission. |
Electrophysiological recordings in hippocampal slices from GGA3 null mice, immunohistochemistry for inhibitory synapses |
PloS one |
Medium |
27192432
|