| 2004 |
Rab40c was cloned from an oligodendrocyte cDNA library and found to bind GTPγS (Kd ~21 µM) with higher affinity for GTP than GDP, and is localized in the perinuclear recycling compartment, suggesting involvement in endocytic receptor recycling; the carboxyl-terminal extension contains motifs permitting isoprenylation and palmitoylation. |
GTP-binding assay (radiolabeled nucleotide binding), subcellular fractionation/immunolocalization, sequence/structural analysis of domain architecture |
Journal of neuroscience research |
Medium |
15160388
|
| 2011 |
RAB40C is a direct transcriptional target of the microRNA let-7a; let-7a binds the 3'-UTR of RAB40C mRNA to repress its expression post-transcriptionally, and RAB40C mediates the pro-proliferative effects of let-7a loss in gastric cancer cells. |
3'-UTR luciferase reporter assay, let-7a overexpression with RAB40C rescue, in vivo xenograft model |
Carcinogenesis |
Medium |
21349817
|
| 2013 |
Rab40c localizes to lipid droplet surfaces (not Golgi or endosomal compartments) and to ERGIC-53-positive structures, is increasingly recruited during lipid droplet formation and maturation, and its knockdown reduces lipid droplet size. Overexpression causes lipid droplet clustering dependent on an intact SOCS box but independent of GTPase activity. Rab40c physically interacts with TIP47 and displays self-interaction; the SOCS box is required for clustering. |
GFP-fusion live imaging and co-localization with neutral lipid dyes (Oil Red O, Nile Red), sucrose-density-gradient fractionation, siRNA knockdown with morphometric analysis, Co-IP (Rab40c–TIP47), SOCS-box deletion mutants, GTPase-dead mutants |
PloS one |
High |
23638186
|
| 2015 |
Rab40C binds the ANKR2 domain of Varp via a direct protein–protein interaction and promotes proteasomal degradation of Varp in a SOCS-box-dependent manner; this reduces Tyrp1 trafficking in melanocytes. Conversely, Rab40C knockdown increases Varp levels and also reduces Tyrp1 signals. |
Co-IP (Rab40C–Varp ANKR2 domain), overexpression and knockdown in melanocytes, proteasome inhibitor rescue, immunofluorescence of Tyrp1 trafficking |
Biology open |
High |
25661869
|
| 2015 |
Methods for analyzing Rab40c association with lipid droplets were established, confirming localization via fluorescence confocal microscopy and sucrose-density centrifugation fractionation, and demonstrating that Rab40c protein level increases during adipocyte differentiation of 3T3-L1 cells. |
Fluorescence confocal microscopy (GFP-Rab40c + lipid-dye co-localization), sucrose-density centrifugation fractionation, immunoblot during adipocyte differentiation |
Methods in molecular biology |
Medium |
25702114
|
| 2017 |
DAB2IP, a RasGAP, binds RAB40C primarily through its GAP domain and acts as a GTPase-activating protein (GAP) for RAB40C. DAB2IP overexpression negatively regulates RAB40C's effect on lipid droplet homeostasis; a GAP-defective DAB2IP mutant and siRNA depletion of DAB2IP both confirm this regulatory relationship. RAB40C deletion by CRISPR-Cas9 causes over-accumulation of lipid droplets. |
Co-IP (RAB40C–DAB2IP), GAP-defective DAB2IP mutant overexpression, siRNA depletion of DAB2IP, CRISPR-Cas9 knockout of RAB40C with lipid droplet quantification |
Oncotarget |
High |
29156729
|
| 2018 |
RAB40C functions as a ubiquitin E3 ligase (via its SOCS box recruiting a CRL complex) responsible for ubiquitination and proteasomal degradation of the scaffolding protein RACK1; RAB40C-mediated control of RACK1 levels affects cancer cell growth and T-cell migration. |
siRNA screen identifying RAB40C, ubiquitination assay, RACK1 stability assay following RAB40C knockdown, functional readouts (cell growth, T-cell migration) |
Future science OA |
Medium |
30112187
|
| 2022 |
Rab40c forms a Cullin5-based ubiquitin E3 ligase complex (Rab40c/CRL5), binds the PP6 phosphatase complex subunit ANKRD28, and promotes its ubiquitylation leading to lysosomal degradation. This reduces PP6 activity, increases phosphorylation of FAK and MOB1, and regulates focal adhesion number, size, and distribution in migrating MDA-MB-231 cells. |
Rab40c knockout cells (CRISPR), Co-IP (Rab40c–PP6 complex/ANKRD28), mass spectrometry identification of ubiquitylation, phosphoproteomics (FAK, MOB1 phosphorylation), immunofluorescence of focal adhesions |
Life science alliance |
High |
35512830
|
| 2025 |
RAB40C is a downstream transcriptional target of STAT3 and promotes K63-linked ubiquitination of EGFR at Lys713 by recruiting the E3 ligase TRIM21, thereby stabilizing EGFR protein and sustaining downstream EGFR signaling in hepatocellular carcinoma cells. |
Co-immunoprecipitation (RAB40C–TRIM21–EGFR), mass spectrometry identification of ubiquitination site (Lys713), ubiquitination assay (K63-linked), STAT3 ChIP/reporter linking STAT3 to RAB40C transcription, cell growth/migration and xenograft assays |
Cell communication and signaling |
Medium |
41350889
|
| 2026 |
RAB40C interacts with SNX9 and promotes its degradation via the ubiquitin-proteasome pathway; silencing RAB40C increases SNX9 levels. This RAB40C–SNX9 axis influences Hippo signaling pathway target proteins and modulates proliferation, migration, and invasion of prostate adenocarcinoma cells. |
Co-IP (RAB40C–SNX9), siRNA knockdown of RAB40C with SNX9 immunoblot, proteasome inhibitor rescue, double-knockdown epistasis, Hippo pathway target immunoblot |
Central-European journal of immunology |
Medium |
42245125
|