Identification of a Wnt-induced protein complex by affinity proteomics using an antibody that recognizes a sub-population of β-catenin

Layton, Meredith J.; Faux, Maree C.; Church, Nicole; Catimel, Bruno; Kershaw, Nadia J.; Kapp, Eugene A.; Nowell, Cameron J.; Coates, Janine L; Burgess, Anthony W; Simpson, Richard J.

doi:10.1016/j.bbapap.2012.03.006

Cited by 5 publications

(7 citation statements)

References 56 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Second, a-catenin was required to preserve the b-catenin phosphodegron and association with bTrCP1. These results support earlier observations that full-length APC, but not cancer-associated mutants, protects the b-catenin phosphodegron from the PP2A phosphatase (Su et al 2008) and that APC regulation of b-catenin phosphorylation occurs within a complex that includes a-catenin (Layton et al 2012). Third, we showed that a-catenin recognizes the APC CID and selectively stabilizes binding of b-catenin to the native APC complex.…”

Section: A Role For A-catenin In the Apc Destruction Complexsupporting

confidence: 79%

See 1 more Smart Citation

α-Catenin interacts with APC to regulate β-catenin proteolysis and transcriptional repression of Wnt target genes

et al. 2013

View full text Add to dashboard Cite

Mutation of the adenomatous polyposis coli (APC) tumor suppressor stabilizes b-catenin and aberrantly reactivates Wnt/b-catenin target genes in colon cancer. APC mutants in cancer frequently lack the conserved catenin inhibitory domain (CID), which is essential for b-catenin proteolysis. Here we show that the APC CID interacts with a-catenin, a Hippo signaling regulator and heterodimeric partner of b-catenin at cell:cell adherens junctions. Importantly, a-catenin promotes b-catenin ubiquitylation and proteolysis by stabilizing its association with APC and protecting the phosphodegron. Moreover, b-catenin ubiquitylation requires binding to a-catenin. Multidimensional protein identification technology (MudPIT) proteomics of multiple Wnt regulatory complexes reveals that a-catenin binds with b-catenin to LEF-1/TCF DNA-binding proteins in Wnt3a signaling cells and recruits APC in a complex with the CtBP:CoREST:LSD1 histone H3K4 demethylase to regulate transcription and b-catenin occupancy at Wnt target genes. Interestingly, tyrosine phosphorylation of a-catenin at Y177 disrupts binding to APC but not b-catenin and prevents repression of Wnt target genes in transformed cells. Chromatin immunoprecipitation studies further show that a-catenin and APC are recruited with b-catenin to Wnt response elements in human embryonic stem cells (hESCs). Knockdown of a-catenin in hESCs prevents the switch-off of Wnt/b-catenin transcription and promotes endodermal differentiation. Our findings indicate a role for a-catenin in the APC destruction complex and at Wnt target genes.

show abstract

Section: A Role For A-catenin In the Apc Destruction Complexsupporting

confidence: 79%

“…Previous studies detected a-catenin in the APC destruction complex (Su et al 1993;Layton et al 2012), but it is not known to have a functional role. Because indirect binding of a-catenin to APC would not explain its prevalence in the complex, we asked whether b-catenin is required for a-catenin to associate with APC.…”

Section: Resultsmentioning

confidence: 99%

α-Catenin interacts with APC to regulate β-catenin proteolysis and transcriptional repression of Wnt target genes

et al. 2013

View full text Add to dashboard Cite

show abstract

“…with the cell-cell adhesion pathway) or modulation of pathway behavior due to sequestration to binding partners. Further, this Wnt pathway description has recently been challenged by evidence of APC-independent β-catenin degradation [ 14 , 15 ], APC-associated phosphorylation of β-catenin independent of Axin (and surprisingly mediated by β-catenin itself) [ 16 ], Wnt activation of different phospho-forms of β-catenin [ 17 , 18 ] and β-catenin ubiquitination [ 19 ]. Clearly the regulation of β-catenin is more complex than the traditional account of Wnt Signaling, so much so that the pathways controlling cytosolic/membrane β-catenin concentrations need to be revisited.…”

Section: Introductionmentioning

confidence: 99%

Analysis of Wnt signaling β-catenin spatial dynamics in HEK293T cells

et al. 2014

View full text Add to dashboard Cite

BackgroundWnt/β-catenin signaling is involved in different stages of mammalian development and implicated in various cancers (e.g. colorectal cancer). Recent experimental and computational studies have revealed characteristics of the pathway, however a cell-specific spatial perspective is lacking. In this study, a novel 3D confocal quantitation protocol is developed to acquire spatial (two cellular compartments: nucleus and cytosol-membrane) and temporal quantitative data on target protein (e.g. β-catenin) concentrations in Human Epithelial Kidney cells (HEK293T) during perturbation (with either cycloheximide or Wnt3A). Computational models of the Wnt pathway are constructed and interrogated based on this data.ResultsA single compartment Wnt pathway model is compared with a simple β-catenin two compartment model to investigate Wnt3A signaling in HEK293T cells. When protein synthesis is inhibited, β-catenin decreases at the same rate in both cellular compartments, suggesting diffusional transport is fast compared to β-catenin degradation in the cytosol. With Wnt3A stimulation, the total amount of β-catenin rises throughout the cell, however the increase is initially (~first hour) faster in the nuclear compartment. While both models were able to reproduce the whole cell changes in β-catenin, only the compartment model reproduced the Wnt3A induced changes in β-catenin distribution and it was also the best fit for the data obtained when active transport was included alongside passive diffusion transport.ConclusionsThis integrated 3D quantitation imaging protocol and computational modeling approach allowed cell-specific compartment models of the signaling pathways to be constructed and analyzed. The Wnt models constructed in this study are the first for HEK293T and have suggested potential roles of inter-compartment transport to the dynamics of signaling.

show abstract

“…However, recent data show that not all phosphorylated β‐catenin is degraded and that distinct complexes of phospho‐β‐catenin are present at different subcellular locations and are likely to have specific functions at these locations, for example, phosphorylated β‐catenin has been implicated in microtubule regrowth at centrosomes, and cell adhesion . In addition, it has been suggested that a recently identified Wnt3a‐induced phospho‐β‐catenin‐APC‐α‐catenin complex is involved in Wnt3a‐mediated changes in cell–cell adhesion in HEK293 cells …”

Section: Lgr5 Rspo and Wnt Signalingmentioning

confidence: 99%

“…76 In addition, it has been suggested that a recently identified Wnt3a-induced phospho-b-catenin-APC-a-catenin complex is involved in Wnt3a-mediated changes in cell-cell adhesion in HEK293 cells. 77 Wnt initiates signaling by binding to a receptor complex composed of Frizzled (FZD) and lipoprotein receptor-related protein 5/6 (LRP5/6). The Wnt-FZD-LRP5/6 complex inhibits the degradation of bcatenin [ Fig.…”

Section: R-spondins Are Ligands Of Lgr5mentioning

confidence: 99%

Structure and function of LGR5: An enigmatic G‐protein coupled receptor marking stem cells

2014

Self Cite

View full text Add to dashboard Cite

G-protein coupled receptors (GPCRs) are an important class of membrane protein that transmit extracellular signals invoked by sensing molecules such as hormones and neurotransmitters. GPCR dysfunction is implicated in many diseases and hence these proteins are of great interest to academia and the pharmaceutical industry. Leucine-rich repeat-containing GPCRs contain a characteristic extracellular domain that is an important modulator of intracellular signaling. One member of this class is the leucine-rich repeat-containing G-protein-coupled receptor 5 (LGR5), a stem cell marker in intestinal crypts, and mammary glands.LGR5 modulates Wnt signaling in the presence of the ligand R-spondin (RSPO). The mechanism of activation of LGR5 by RSPO is not understood, nor is the intracellular signaling mechanism known. Recently reported structures of the extracellular domain of LGR5 bound to RSPO reveal a horseshoe-shaped architecture made up of consecutive leucine-rich repeats, with RSPO bound on the concave surface. This review discusses the discovery of LGR5 and the impact it is having on our understanding of stem cell and cancer biology of the colon. In addition, it covers functional relationships suggested by sequence homology and structural analyses, as well as some intriguing conundrums with respect to the involvement of LGR5 in Wnt signaling.

show abstract

Identification of a Wnt-induced protein complex by affinity proteomics using an antibody that recognizes a sub-population of β-catenin

Cited by 5 publications

References 56 publications

α-Catenin interacts with APC to regulate β-catenin proteolysis and transcriptional repression of Wnt target genes

α-Catenin interacts with APC to regulate β-catenin proteolysis and transcriptional repression of Wnt target genes

Analysis of Wnt signaling β-catenin spatial dynamics in HEK293T cells

Structure and function of LGR5: An enigmatic G‐protein coupled receptor marking stem cells

Contact Info

Product

Resources

About