| 2002 |
RHOBTB2 (DBC2) expression in breast cancer cells lacking DBC2 transcripts causes growth inhibition, establishing a functional tumor suppressor role; a somatic missense mutant discovered in a breast cancer specimen does not suppress growth, indicating loss-of-function relevance. |
Ectopic expression in DBC2-negative breast cancer cells, growth inhibition assay; somatic mutant functional comparison |
Proceedings of the National Academy of Sciences of the United States of America |
Medium |
12370419
|
| 2004 |
RhoBTB2 binds to the ubiquitin ligase scaffold Cul3 via its first BTB domain, and is itself a substrate for ubiquitination and proteasomal degradation by the Cul3-based ubiquitin ligase complex both in vitro and in vivo. A lung cancer-derived missense mutant of RhoBTB2 is unable to bind Cul3 and is not regulated by the ubiquitin/proteasome system, resulting in elevated RhoBTB2 protein levels. |
Co-immunoprecipitation (binding to Cul3), in vitro and in vivo ubiquitination assays, domain mapping (BTB1 domain), analysis of cancer-derived mutant |
Genes & development |
High |
15107402
|
| 2006 |
DBC2/RhoBTB2 is required for microtubule-dependent vesicular transport of VSV-G glycoprotein from the ER to the Golgi apparatus; RhoBTB2 mobility itself depends on an intact microtubule network. |
siRNA knockdown of DBC2 in 293 cells; VSVG-GFP transport assay; microtubule disruption experiments |
Journal of molecular biology |
Medium |
17023000
|
| 2007 |
RhoBTB2 is a direct transcriptional target of E2F1; RhoBTB2 expression is upregulated by E2F1 overexpression even in the presence of cycloheximide (indicating direct regulation), and RNAi knockdown of E2F1 decreases RhoBTB2 protein. RhoBTB2 expression is elevated during mitosis and during drug-induced apoptosis in an E2F1-dependent manner; siRNA knockdown of RhoBTB2 delays drug-induced apoptosis. |
E2F1 overexpression with cycloheximide treatment, siRNA knockdown of E2F1 and RhoBTB2, cell cycle analysis, apoptosis assays |
The Journal of biological chemistry |
Medium |
18039672
|
| 2007 |
DBC2 suppresses breast cancer proliferation through down-regulation of Cyclin D1 (CCND1); constitutive overexpression of CCND1 (or CCNE1 under the CCND1 promoter) prevents the growth-suppressive effect of DBC2, establishing CCND1 down-regulation as an essential step in DBC2's tumor suppressor mechanism. |
DBC2 expression in breast cancer cells, CCND1 overexpression rescue experiment, cell proliferation assays |
Biochemical and biophysical research communications |
Medium |
17517369
|
| 2007 |
DBC2-resistant breast cancer cells survive DBC2 induction by rapid degradation of DBC2 protein via the 26S proteasome; proteasome inhibition (MG132) restores DBC2 protein detection in resistant cells. |
Inducible DBC2 expression system, MG132 proteasome inhibitor treatment, Western blot |
Biochemical and biophysical research communications |
Medium |
17617377
|
| 2008 |
Loss of RhoBTB2 expression in primary human epithelial cells results in down-regulation of CXCL14; reintroduction of RhoBTB2 into head and neck squamous cell carcinoma lines restores CXCL14 secretion, identifying CXCL14 as a downstream gene target of RhoBTB2. |
siRNA knockdown in primary human epithelial cells, microarray gene expression analysis, CXCL14 secretion assay, RhoBTB2 re-expression in cancer cell lines |
Oncogene |
Medium |
18762809
|
| 2008 |
The Cul3 ubiquitin ligase complex ubiquitinates RhoBTB2 directly, leading to its degradation by the proteasome; detailed cell biological and biochemical methods for analyzing this regulation are established. |
Co-immunoprecipitation, in vitro ubiquitination assay, proteasome inhibitor experiments (methods review paper) |
Methods in enzymology |
Medium |
18374159
|
| 2014 |
DBC2/RhoBTB2 associates with Hsp90 and its co-chaperone Cdc37 in reticulocyte lysate and MCF7 cells; DBC2 retains the capacity to bind GTP, which is modulated by the Hsp90 ATPase cycle (geldanamycin suppresses GTP binding; molybdate enhances it). Assembly of DBC2–Cul3–COP9 E3 ligase complexes is Hsp90-dependent. |
Pull-down assays, GTP-binding assays, Hsp90 inhibitor (geldanamycin) and stabilizer (molybdate) treatment, co-immunoprecipitation of DBC2-Cul3-COP9 complex |
PloS one |
Medium |
24608665
|
| 2016 |
DBC2/RhoBTB2 acts as a substrate-specific adaptor for the Cul3-based E3 ubiquitin ligase; it directly interacts with Musashi-2 (MSI2), promoting MSI2 polyubiquitination and proteasomal degradation in breast cancer cells. DBC2 overexpression suppresses MSI2-associated oncogenic functions and induces apoptosis; DBC2 and MSI2 protein levels are inversely correlated in breast cancer tissues. |
Genome-wide cDNA library-based in vitro ubiquitination target screen, co-immunoprecipitation (DBC2–MSI2 interaction), overexpression and siRNA knockdown experiments, proteasomal degradation assays, IHC tissue microarray |
Oncogene |
High |
27941885
|
| 2010 |
Ectopic RhoBTB2 expression inhibits migration and invasion of metastatic breast cancer cells by upregulating the metastasis suppressor BRMS1 and decreasing phosphorylation of ezrin and Akt2; siRNA knockdown of BRMS1 reverses RhoBTB2-mediated inhibition of migration and invasion. |
Ectopic RhoBTB2 expression, siRNA knockdown of BRMS1, Transwell migration/invasion assays, Western blot for BRMS1, phospho-ezrin, and phospho-Akt2 |
Cancer biology & therapy |
Medium |
20930524
|
| 2018 |
De novo missense variants in RHOBTB2 BTB domains result in mutant protein accumulation; co-expression of CUL3 with wild-type RHOBTB2 decreased WT protein levels but not those of any of three disease-associated mutants, demonstrating that disease-causing variants impair CUL3-dependent proteasomal degradation of RHOBTB2. |
Transient expression in Neuro-2a cells, co-expression with CUL3, Western blot quantification of WT vs mutant RHOBTB2 protein levels |
Human mutation |
Medium |
29768694
|
| 2025 |
BTB-domain variants of RHOBTB2 (R461H, R485C, R489Q) cause increased RHOBTB2 protein accumulation with nuclear and mitochondrial localization, and lead to significantly altered neuronal excitability (measured by patch-clamp) and downregulation of ion channel genes including those related to sodium channels (paralytic/SCN1A ortholog). GTPase-domain variants (D92H, W217C) do not alter protein levels but reduce Na+/K+-ATPase protein via lysosome-dependent degradation. Functional genetic interaction between RhoBTB and paralytic (SCN1A ortholog) was confirmed in Drosophila in vivo. Complete loss of RHOBTB2 does not produce the same neuronal excitability phenotype as BTB-domain variants. |
Drosophila RNA-seq on fly heads overexpressing RhoBTB, genetic interaction experiments in flies; patch-clamp recordings on iPSC-derived neurons with homozygous frameshifts or patient-specific missense variants; doxycycline-inducible cell model; protein localization analysis; RNA-seq in cell model; lysosome inhibitor experiments |
Human molecular genetics / Biochimica et biophysica acta. Molecular cell research |
High |
39849855 41478322
|
| 2025 |
In AML cells, RHOBTB2 directly interacts with KLHL13 (validated by co-immunoprecipitation); RHOBTB2 stabilizes KLHL13 protein by inhibiting its proteasomal degradation (MG132 reverses KLHL13 loss upon RHOBTB2 knockdown). RHOBTB2 promotes AML cell proliferation and migration and suppresses apoptosis, acting through KLHL13 and the Hippo-YAP1 pathway. |
Co-immunoprecipitation (RHOBTB2–KLHL13), siRNA knockdown, MG132 proteasome inhibitor rescue, Western blot, CCK-8 proliferation assay, Transwell assay, Annexin V/PI apoptosis assay |
Scientific reports |
Medium |
41107424
|