| 2012 |
SGTA contains a noncanonical ubiquitin-like-binding domain (UBD) that interacts specifically with the unconventional ubiquitin-like domain of Ubl4A, at least in part via electrostatics. This interaction recruits SGTA to the BAG6 complex, enhances substrate loading to BAG6, and prevents formation of nondegradable protein aggregates during ERAD. |
NMR spectroscopy, biochemical binding assays, co-immunoprecipitation |
Cell Reports |
High |
23246001
|
| 2010 |
Get4 (TRC35) and Get5 (UBL4A/Mdy2) form a tight complex in yeast, and Get3 specifically binds to a conserved surface on Get4 in a nucleotide-dependent manner, placing Get4/5 upstream of Get3 in the tail-anchored protein targeting pathway. |
Crystal structure of Get4/Get5 N-terminal fragment, co-immunoprecipitation, isothermal titration calorimetry |
Proceedings of the National Academy of Sciences |
High |
20106980 20554915
|
| 2012 |
The N-terminal dimerization domain of Sgt2/SGTA directly binds the UBL domain of Get5/UBL4A via electrostatics, forming a high-affinity complex with rapid kinetics, structurally characterized for both yeast and human protein pairs. |
Crystal structures (yeast and human UBD/UBL complex), biophysical studies (ITC, NMR chemical shift perturbation) |
Cell Reports |
High |
23142665
|
| 2013 |
Solution structure of Sgt2_NT (unique helical fold) and crystal structure of Get5_UBL determined; NMR chemical shift perturbation and ITC establish a 1:2 stoichiometry (one Get5 UBL to one Sgt2 dimer); site-directed mutagenesis validated the binding interface. |
NMR solution structure, crystal structure, isothermal titration calorimetry, site-directed mutagenesis, relaxation experiments |
Proceedings of the National Academy of Sciences |
High |
23297211
|
| 2014 |
Crystal structure of yeast Get3-Get4-Get5 ternary complex in an ATP-bound state reveals that Get4 primes Get3 by promoting an optimal configuration for TA substrate capture; Get4-mediated regulation of Get3 ATP hydrolysis is essential for efficient TA-protein targeting. |
Crystal structure, structure-guided biochemical assays, ATPase activity measurements |
Nature Structural & Molecular Biology |
High |
24727835
|
| 2015 |
Crystal structure of the C-terminal heterodimerization domains of BAG6 and Ubl4A reveals a novel binding interface; the BAG6 C-terminus (designated BAGS domain) is structurally distinct from canonical BAG domains. Tight association of BAG6 and Ubl4A modulates Ubl4A protein stability in cells. |
Crystal structure, biochemical binding assays, cell-based stability assays |
Journal of Biological Chemistry |
High |
25713138
|
| 2014 |
NMR solution structure of the SGTA dimerization domain determined; UBL domains from UBL4A and BAG6 compete for binding to SGTA at the same site, characterized by NMR chemical shift perturbation, ITC, and microscale thermophoresis; HADDOCK docking models of SGTA-UBL complexes generated. |
NMR structure determination, ITC, microscale thermophoresis, NMR chemical shift perturbation |
PLoS ONE |
High |
25415308
|
| 2013 |
Nuclear BAG6-UBL4A-GET4 complex mediates DNA damage signaling and cell death. Upon DNA damage, UBL4A and GET4 translocate to the nucleus. Depletion of BAG6 causes loss of both UBL4A and GET4 proteins. Co-depletion of UBL4A and GET4 (but not single depletion) confers resistance to DNA damage-induced cell death. All three components regulate BRCA1 recruitment to DNA damage sites. |
siRNA knockdown, cell viability assays, immunofluorescence for nuclear translocation, BRCA1 recruitment assays |
Journal of Biological Chemistry |
Medium |
23723067
|
| 2015 |
Ubl4A directly interacts with the Arp2/3 complex to accelerate actin branching and networking, enabling insulin-induced Akt translocation to the plasma membrane. Ubl4A knockout mice have defective Akt-dependent glycogen synthesis. Akt binds actin filaments and colocalizes with Arp2/3 in membrane ruffles. |
Protein-protein interaction assays, actin branching in vitro assays, Ubl4A knockout mouse model, live-cell imaging of Akt translocation, glycogen synthesis assays |
Proceedings of the National Academy of Sciences |
High |
26195787
|
| 2016 |
Ubl4A, F-actin, and Arp2/3 co-localize at cell leading edges during wound closure. Knockout of Ubl4A reduces actin-mediated membrane protrusion, delays wound healing in primary mouse embryonic fibroblasts, impairs fibroblast migration from corneal tissue ex vivo, and decreases macrophage motility without affecting phagocytosis. |
Ubl4A KO mouse model, wound-healing assay, immunofluorescence co-localization, ex vivo migration assay, macrophage motility and phagocytosis assays |
Biochemical and Biophysical Research Communications |
Medium |
27998771
|
| 2018 |
The C-terminal region of Ubl4A directly interacts with the Arp2/3 complex in pull-down assays. A point mutation D122A in the C-terminus abolishes Arp2/3 binding and destabilizes Ubl4A. Wild-type Ubl4A induces cell death in colon cancer cells via its C-terminal Arp2/3-binding activity, while D122A mutant loses this pro-death activity. |
In vitro protein pull-down, site-directed mutagenesis (D122A), cell death assays |
Biochemical and Biophysical Research Communications |
Medium |
30146258
|
| 2019 |
GdX/UBL4A positively regulates NF-κB signaling in dendritic cells and macrophages by trapping TC45 (PTPN2), thereby disrupting the TC45/PP2A/p65 complex that mediates p65 dephosphorylation and preventing p65 dephosphorylation. |
Immunoprecipitation, luciferase reporter assay, LPS challenge of GdX-deficient mice, cytokine ELISA, DSS colitis model with tissue-specific KO mice |
Theranostics |
Medium |
30867837
|
| 2019 |
UBL4A interacts with TRAF6 via co-immunoprecipitation, and this interaction is enhanced upon viral infection. UBL4A promotes K63-linked ubiquitination of TRAF6, enhancing TBK1, IRF3, and IKKα/β phosphorylation and type I IFN transcription. |
Co-immunoprecipitation, ubiquitination assay (K63-specific), siRNA knockdown and overexpression, phosphorylation western blots |
Journal of Immunology |
Medium |
31451677
|
| 2019 |
UBL4A directly interacts with LAMP1 by co-immunoprecipitation and causes lysosomal dysfunction leading to impaired autophagic degradation and autophagosome accumulation in pancreatic cancer cells. LAMP1 overexpression reverses the antitumor effects of UBL4A. |
Co-immunoprecipitation, western blot autophagy markers, in vitro and in vivo (orthotopic) functional assays |
Journal of Experimental & Clinical Cancer Research |
Medium |
31288830
|
| 2020 |
Ubl4A promotes mitochondrial fusion under nutrient deprivation via its interaction with the Arp2/3 complex. Ubl4A deficiency reduces the primed Arp2/3 complex pool around mitochondria, impairs fusion, causes mitochondrial fragmentation, ROS accumulation, and caspase 9-dependent apoptosis. An Arp2/3-binding-deficient Ubl4A mutant fails to rescue this phenotype. |
Ubl4A KO cells and rescue with wild-type vs. Arp2/3-binding mutant, mitochondrial morphology imaging, ROS measurement, caspase 9 activity assay |
PLoS ONE |
Medium |
33211772
|
| 2023 |
Disease-associated polyglutamine inclusions disrupt formation of the BAG6-UBL4A complex. UBL4A also dissociates from BAG6 in response to proteasomal inhibition and mitochondrial depolarization (proteotoxic stresses), implying that disruption of the BAG6-UBL4A complex contributes to impaired TA protein biogenesis under stress. |
Co-immunoprecipitation under proteotoxic stress conditions (polyglutamine, proteasome inhibitor, mitochondrial depolarizing agent) |
Biochemical Journal |
Medium |
37747814
|
| 2007 |
Yeast Mdy2 (UBL4A ortholog) interacts with the N-terminal region of Sgt2, and Mdy2 also physically interacts with the chaperone Ydj1, potentially mediating association between Ydj1 and Sgt2. MDY2 interacts genetically with YDJ1. |
Co-immunoprecipitation, genetic interaction (synthetic lethality/mating efficiency assay) |
Cell Stress & Chaperones |
Medium |
17441508
|
| 2006 |
Yeast Mdy2 (UBL4A ortholog) contains a UBL domain but shows no evidence of C-terminal processing typical of ubiquitin. In mdy2Δ cells, microtubule bundles and the MT end-binding protein Kar9 fail to localize properly to the shmoo tip, causing defects in nuclear migration and karyogamy during mating. |
Deletion mutant phenotypic analysis, GFP localization, His-tag processing assay, immunofluorescence of microtubules and Kar9 |
Journal of Cell Science |
Medium |
16390866
|
| 2010 |
Yeast Mdy2 (UBL4A ortholog) associates with α-tubulin and the dynactin subunit p150(Glued)/Nip100. Under heat stress, nuclear Mdy2 relocalizes to cytoplasmic stress granules co-marked by Pab1 (poly(A)-binding protein). |
Co-precipitation, GFP live imaging, colocalization with stress granule markers |
Cytoskeleton |
Medium |
20722039
|
| 2012 |
Nuclear import of yeast Mdy2 (UBL4A ortholog) is mediated by an N-terminal nuclear localization signal (NLS) and is required for heat stress response. Mdy2 physically interacts with Pab1 and this interaction (and accumulation in stress granules) depends on nuclear history (NLS intact), not nuclear retention (NES deletion has no effect). |
NLS/NES deletion mutants, GFP localization, co-precipitation with Pab1, heat stress viability assays |
PLoS ONE |
Medium |
23285234
|
| 2013 |
Crystal structure of the Sgt2 dimerization domain complexed with the Get5 UBL domain (yeast) reveals one Sgt2 dimer binding one Get5 monomer via hydrophobic residues from both proteins; these hydrophobic interface residues are important for cell survival under heat stress. |
Crystal structure, mutagenesis, heat stress cell survival assay |
Acta Crystallographica Section D |
High |
24100326
|
| 2024 |
GdX/UBL4A directly interacts with STAT3 (confirmed by dual-luciferase reporter and immunofluorescence) and overexpression of GdX reduces phosphorylation of STAT3, inhibiting downstream STAT3 target genes BCL-XL, Cyclin D1, and c-Myc in breast cancer cells. |
Dual-luciferase reporter assay, immunofluorescence co-localization, western blot phosphorylation assay, KO mouse tumor model |
Cancer Biology & Therapy |
Low |
39487760
|
| 2011 |
In yeast, sgt2Δ get5Δ double mutants show more severe TA protein sorting defects than either single knockout, indicating cooperative functions. Overproduction of Sgt2 is toxic in get3Δ but not get5Δ cells, indicating a Get5-independent role for Sgt2 in TA protein delivery to Get3. |
Genetic epistasis (double-mutant analysis), TA protein sorting assays, overexpression toxicity assay |
Biological Chemistry |
Medium |
21619481
|