| 2001 |
RHOU/Wrch-1 was identified as a Wnt-1-regulated Cdc42 homolog that activates PAK-1 and JNK-1, induces filopodium formation and stress fiber dissolution, and stimulates quiescent cells to re-enter the cell cycle. |
Functional overexpression assays, kinase activation assays, morphological transformation assays in mouse mammary epithelial cells |
Genes & development |
High |
11459829
|
| 2004 |
RHOU/Wrch-1 possesses an extremely rapid intrinsic guanine nucleotide exchange activity (unlike Cdc42) and negligible GTPase activity, rendering it constitutively GTP-bound; its unique N-terminal 46 aa extension negatively regulates effector interaction and transformation, and the adaptor protein Grb2 binds the N-terminus to overcome this negative regulation and promote Wrch-1 effector interaction. |
In vitro nucleotide exchange and GTPase assays, N-terminal truncation mutagenesis, Co-IP of Grb2, PAK activation assays, transformation assays |
Current biology : CB |
High |
15556869
|
| 2004 |
RHOU/Wrch1 has no detectable GTPase activity in vitro and extremely high intrinsic nucleotide exchange; it interacts with PAK1 and NCKβ, with the NCKβ interaction mediated through PxxP motifs in the N-terminal extension binding the second and third SH3 domains of NCKβ. |
In vitro GTPase and nucleotide exchange biochemical assays, pulldown/binding experiments with PAK1 and NCKβ SH3 domains |
Experimental cell research |
High |
15350535
|
| 2005 |
RHOU/Wrch-1 membrane localization and transforming activity depend on palmitoylation of the second cysteine of its C-terminal CCFV motif, not on isoprenylation; mutation of this cysteine (C→S) abrogates both plasma membrane/endosome localization and transformation. |
Isoprenoid incorporation assays, palmitate incorporation assays, prenylation inhibitor treatment, palmitoylation inhibitor treatment, site-directed mutagenesis (CCFV→CSFV and CCFV→SCFV), subcellular fractionation, transformation assays |
The Journal of biological chemistry |
High |
16046391
|
| 2007 |
RHOU/Wrch-1 localizes to focal adhesions via a bipartite signal requiring both the C-terminal extension (including the palmitoylation-independent region) and the effector binding loop; activated RhoU reduces focal adhesion number and distribution and increases cell migration rate. |
Live-cell fluorescence imaging, domain deletion and point mutants, siRNA knockdown, wound-healing migration assays |
Biology of the cell |
High |
17620058
|
| 2007 |
RHOU/Wrch-1 localizes to focal adhesions and its depletion by siRNA increases focal adhesion number and inhibits myosin light chain phosphorylation and cell migration; Wrch-1 also activates Akt and JNK to promote migration. |
siRNA knockdown, overexpression, immunofluorescence of focal adhesions, myosin light chain phosphorylation western blot, wound healing assay, pharmacological inhibition of Akt and JNK |
Journal of cell science |
High |
17504809
|
| 2007 |
RHOU/Wrch1 binds the non-receptor tyrosine kinase Pyk2 in a GTP-dependent manner requiring both the N-terminal proline-rich extension and intact effector loop; Src kinase activity is required for formation of the Wrch1-Pyk2 complex and for Wrch1-induced filopodium formation. |
Co-IP, siRNA knockdown of Pyk2 and Src, dominant-negative Src, GTP-binding mutant analysis, cytoskeletal phenotype assays |
Molecular and cellular biology |
High |
18086875
|
| 2008 |
RHOU/Wrch1 binds integrin β3 cytoplasmic domain, localizes to podosomes, and its expression reduces osteoclast precursor adhesion to vitronectin (but not fibronectin) while interfering with adhesion-induced Pyk2 and paxillin phosphorylation; high Wrch1 activity inhibits podosome belt formation in mature osteoclasts. |
Pulldown assay with integrin β3 cytoplasmic domain peptide, siRNA knockdown, overexpression, adhesion assays on vitronectin/fibronectin, podosome imaging, phospho-Pyk2 and phospho-paxillin western blot |
The international journal of biochemistry & cell biology |
High |
19135548
|
| 2008 |
Activated RHOU/Wrch-1 binds the cell polarity protein Par6 in a GTP-dependent manner and disrupts tight junction assembly kinetics during epithelial polarization; an effector domain mutant of activated Wrch-1 that abrogates Par6 binding also abrogates disruption of tight junction formation, actin organization, and epithelial morphogenesis. |
Co-IP (GTP-dependent Par6 binding), effector domain mutagenesis, shRNA knockdown, 2D and 3D (cystogenesis) culture assays, tight junction kinetics assay |
Molecular and cellular biology |
High |
19064640
|
| 2009 |
RHOU/Wrch1 transcription is induced by gp130 cytokines via STAT3 (two functional STAT3-binding sites identified on the mouse RhoU promoter) and by Wnt-1 independently of β-catenin via the non-canonical Wnt/planar cell polarity pathway through JNK activation. |
Reporter assays, chromatin immunoprecipitation for STAT3 binding sites, β-catenin inhibition, JNK pathway analysis, promoter deletion analysis |
The Biochemical journal |
High |
19397496
|
| 2010 |
Src phosphorylates RHOU/Wrch-1 at tyrosine Y254 within its C-terminal membrane targeting domain upon serum stimulation, causing relocalization from plasma membrane to endosomes, reducing GTP loading and PAK effector activation; phospho-deficient Y254F mutant remains at plasma membrane, stays GTP-bound, and continues to activate PAK. |
Site-directed mutagenesis (Y254F phospho-deficient, Y254E phospho-mimetic), Src genetic and pharmacological inhibition, subcellular fractionation, GTP-loading assays, PAK activation assay, 3D cystogenesis assay |
Molecular and cellular biology |
High |
20547754
|
| 2010 |
RHOU/RhoU activates pathways cooperating with PAK1 and Rac1 to regulate epithelial adhesion, cell spreading and directional cranial neural crest cell migration in Xenopus; gain- and loss-of-function of RhoU demonstrate its critical role in CNC cell migration and subsequent craniofacial cartilage differentiation. |
Gain- and loss-of-function (morpholino knockdown and mRNA injection) in Xenopus embryos, in vitro spreading/migration assays, PAK1 and Rac1 epistasis |
Developmental biology |
High |
21156169
|
| 2011 |
RHOU/Wrch-1 GTP-dependent activation is coupled to EGF receptor signaling through physical association of RhoU with activated EGFR via GRB2 (binding through N-terminal proline-rich motifs of RhoU); mutation of these proline-rich sequences or GRB2 siRNA abrogates EGFR interaction and EGF-stimulated RhoU GTP loading, AP1 transcriptional activity, and cell migration. |
Co-IP of RhoU with activated EGFR, proline-rich motif mutagenesis, GRB2 siRNA knockdown, GTP-loading pull-down assay, AP1 luciferase reporter, migration assay |
Molecular biology of the cell |
High |
21508312
|
| 2011 |
RHOU/Wrch-1 knockdown in mouse embryonic foregut causes disrupted endoderm epithelial architecture, loss of microvilli, reduced F-actin in apical cortical domain, and impaired endoderm differentiation associated with reduced c-Jun/AP-1 target gene expression, consistent with a role for Rhou in JNK activity regulation. |
ES cell-based knockdown, embryoid body differentiation, phalloidin F-actin staining, in vivo mouse embryo analysis, gene expression analysis of AP-1 targets |
Development (Cambridge, England) |
High |
21903671
|
| 2011 |
ARHGAP30, identified in a screen for Wrch-1 binding partners, interacts with Wrch-1 and mediates actin dynamics and cell adhesion downstream of Wrch-1; CdGAP also binds Wrch-1. |
Yeast two-hybrid screen, Co-IP/pulldown validation, overexpression phenotypic assays (membrane blebbing, stress fiber dissolution) |
Biochemical and biophysical research communications |
Medium |
21565175
|
| 2013 |
The N-terminal extension of RHOU/Wrch1 binds multiple SH3 domain-containing adaptor proteins (Grb2, Nck1, c-Src, Crk1, p120) with low affinity through isolated SH3 domains; however, full-length Grb2 and Nck1 bind tightly due to avidity from multiple SH3 domains, with the central PxxP motif (minimal 8 aa with essential adjacent arginine) being the primary determinant. |
Sedimentation assays, isothermal titration calorimetry (ITC), peptide analysis, cell-based Co-IP |
Biological chemistry |
High |
23183748
|
| 2014 |
RhoU regulates cell junctions between cardiomyocytes via the Arhgef7b/PAK kinase pathway to guide atrioventricular canal development and cardiac looping in zebrafish; PAK kinase overexpression rescues RhoU loss-of-function cardiac defects. |
Zebrafish morpholino knockdown, chemical genetic screen (ROCK inhibitor), PAK overexpression rescue, cardiac phenotype analysis |
Developmental biology |
High |
24607366
|
| 2015 |
PAK4 stabilizes RhoU protein in a kinase-independent manner by protecting RhoU from ubiquitination mediated by the Rab40A-Cullin 5 E3 ubiquitin ligase complex; RhoU overexpression rescues PAK4 depletion phenotype on cell adhesion turnover and migration. |
siRNA knockdown, overexpression rescue, ubiquitination assay, Co-IP of RhoU with Rab40A-Cullin 5 complex, adhesion dynamics live imaging, migration assay |
The Journal of cell biology |
High |
26598620
|
| 2019 |
RhoU/Wrch1 loss of function in mouse gut epithelium increases RhoA activity and phosphorylated Myosin Light Chain-2, leading to reduced apoptosis and cell hyperplasia; this functionally links RhoU activity to apoptosis via actomyosin-dependent mechanisms. |
Conditional mouse knockout, DLD-1 siRNA knockdown, RhoA activity pulldown assay (GST-rhotekin), phospho-MLC2 western blot, apoptosis and proliferation assays |
Biology of the cell |
High |
30834544
|
| 2020 |
RhoU interacts with intersectin-2 (ITSN2) through the second PxxP motif of its N-terminus binding ITSN2 SH3 domains; RhoU and ITSN2 co-localize on Rab4-positive fast recycling endosomes, and silencing either RhoU or ITSN2 (but not ITSN1) causes accumulation of transferrin in early endosomes due to a defect in fast vesicle recycling. |
Co-IP, domain mutagenesis (PxxP motifs), fluorescent transferrin uptake assay, siRNA knockdown, colocalization with Rab4 endosomal markers |
Journal of cell science |
High |
32737221
|
| 2024 |
RhoU forms homo-oligomers through its C-terminal extension in a palmitoylation-dependent manner; self-association stimulates RhoU-induced PAK activation, and expression of the isolated C-terminal extension acts as a dominant negative to reduce PAK activation and alter cell morphology. |
Co-IP of RhoU homodimerization, palmitoylation mutant analysis, dominant-negative C-terminal extension expression, PAK activation assay, cell morphology and migration/invasion assays |
Journal of cell science |
High |
38180080
|
| 2024 |
SUMOylated AnxA6 physically associates with RHOU; when AnxA6 is deSUMOylated (K579R mutant), it dissociates from RHOU, leading to upregulation of RHOU-mediated p-AKT1(S473) and increased cell migration and EMT in hepatocellular carcinoma. |
LC-MS/MS identification of SUMOylation site, Co-IP of AnxA6 with RHOU, site-directed mutagenesis (K579R), AKT1 phosphorylation western blot, migration and EMT assays |
Cell communication and signaling : CCS |
Medium |
38566133
|