| 2009 |
RhoBTB3 binds directly to Rab9 GTPase and functions with Rab9 in protein transport from endosomes to the trans-Golgi network. Biochemical analysis revealed that RhoBTB3 binds and hydrolyzes ATP (not GTP), and Rab9 binding opens the autoinhibited RhoBTB3 protein to permit maximal ATP hydrolysis. RhoBTB3 also interacts with TIP47 on membranes, suggesting a role in releasing this cargo selection protein from vesicles for efficient docking and fusion at the Golgi. Gene replacement experiments showed that both the N-terminal Rho-related domain and C-terminal sequences (important for Rab9 interaction) are required for function. |
Direct binding assays, biochemical ATPase activity assays, co-immunoprecipitation, gene replacement experiments in cultured cells |
Cell |
High |
19490898
|
| 2013 |
RhoBTB3 is a Golgi-associated ATPase that targets cyclin E for ubiquitylation as part of a CUL3-dependent RING-E3 ubiquitin ligase complex (RhoBTB3–CUL3–RBX1) at the Golgi. Depletion of RhoBTB3 arrests cells in S phase, triggers Golgi fragmentation, and elevates cyclin E levels. Golgi association of the complex is required for its ability to catalyze cyclin E ubiquitylation and allow normal S/G2 cell cycle progression. |
RNAi depletion, co-immunoprecipitation, ubiquitylation assays, cell cycle analysis, Golgi localization experiments |
The Journal of cell biology |
High |
24145166
|
| 2015 |
RHOBTB3 directly interacts with the prolyl hydroxylase PHD2 to promote HIFα hydroxylation, and directly interacts with VHL (an E3 ubiquitin ligase complex component) to facilitate HIFα ubiquitination. RHOBTB3 dimerizes with LIMD1 and assembles a RHOBTB3/LIMD1–PHD2–VHL–HIFα complex for maximal HIFα degradation. Hypoxia reduces this complex formation, causing HIFα accumulation. RHOBTB3 deficiency elevates the Warburg effect and accelerates xenograft tumor growth. |
Co-immunoprecipitation, ubiquitination assays, hydroxylation assays, RNAi knockdown, xenograft experiments |
Cell research |
High |
26215701
|
| 2012 |
RhoBTB3 interacts with the 5-HT7a serotonin receptor (binding involves both the C-terminal tail and the third intracellular loop of the receptor), co-localizes at the plasma membrane and ER, and inhibits proteasomal degradation of the 5-HT7a receptor. Notably, although RhoBTB3 interacts with CUL3, it does not recruit CUL3/ROC1 to the 5-HT7a receptor and does not mediate receptor ubiquitination. |
Yeast two-hybrid screen, co-immunoprecipitation in HEK293T cells, domain mapping, immunofluorescence microscopy, proteasome inhibition assays |
Cellular signalling |
Medium |
22245496
|
| 2020 |
Depletion of RhoBTB3 affects Golgi complex morphology and causes changes in the trafficking speeds of membrane carriers operating at the Golgi–ER interface. RhoBTB3 was found to be present on these Golgi–ER carriers, indicating a direct role in this trafficking step. |
RNA interference, high-content image-based screening, live-cell imaging of carrier trafficking, fluorescence microscopy |
Cells |
Medium |
32354068
|
| 2024 |
RhoBTB3 forms a complex with SHIP164 and the retromer subunit Vps26B at Golgi–early endosome (EE) contact sites to promote EE bud formation. Vps26B acts as a novel Rab14 effector, and Rab14 activity regulates SHIP164 association with EEs. Suppression of RhoBTB3 phenocopies SHIP164 depletion (enlarged Rab14+ EEs without buds), revealing a lipid-transfer-dependent pathway for EE budding. |
Co-immunoprecipitation, RNAi knockdown, fluorescence microscopy, rescue experiments with lipid-transfer-defective mutants |
Cell discovery |
Medium |
38565878
|
| 2024 |
RhoBTB3 negatively regulates autophagy by acting as an E3 ubiquitin ligase that ubiquitinates AMBRA1 (at K45 via K27-linked ubiquitin chains), promoting its proteasome-mediated degradation. RhoBTB3 deficiency induces autophagy and elevates AMBRA1 protein levels (without affecting AMBRA1 mRNA), while RhoBTB3 overexpression inhibits autophagy induction. AMBRA1 knockdown blocks RhoBTB3-depletion-induced autophagy. |
Immunoprecipitation, mass spectrometry, ubiquitination assays with site-specific mutants (K45), proteasome inhibition assays, RNAi knockdown, overexpression |
Cells |
Medium |
39404422
|
| 2025 |
Diosmetin reduces formation of the RhoBTB3–PHD2 complex in UV-irradiated keratinocytes, thereby limiting HIF-1α hydroxylation and ubiquitination, and stabilizing HIF-1α. Overexpression of RhoBTB3 in mice enriches RhoBTB3, PHD2, and HIF-1α in the epidermis, consistent with RhoBTB3 promoting PHD2-mediated HIF-1α hydroxylation in skin. |
Co-immunoprecipitation, RNA sequencing, rAAV-mediated overexpression in mice, immunohistochemistry, in vivo UV sunburn model |
Phytomedicine |
Medium |
40311591
|
| 2019 |
Genetic deletion of RhoBTB3 in mice leads to increased alpha-granule secretion in platelets in response to thrombin, CRP, and U46619/ADP, and reduces platelet accrual on collagen under flow conditions, without affecting platelet count, granule numbers, surface receptors, aggregation, dense granule secretion, or tail bleeding time. |
Knockout mouse model, flow cytometry, aggregometry, granule secretion assays, collagen adhesion under flow |
Cells |
Medium |
30754723
|