Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:B0FTZ7 (catenin)
 18,795 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

One approach to understanding the function of presenilin 1 (PS1), is to discover those proteins with which it interacts. Evidence for a function in developmental patterning came from C. elegans, in which a PS homologue was identified by screening for suppressors of a mutation in Notch/lin-12, a gene which specifies cell fate. However, this genetic experiment cannot determine which proteins directly interact with PS1. Therefore, we utilized the two hybrid system and confirmatory co-immunoprecipitations to identify a novel catenin, termed delta-catenin, which interacts with PS1 and is principally expressed in brain. The catenins are a gene family related to the Armadillo gene in Drosophila, some of which appear to have dual roles-they are components of cell-cell adherens junctions, and may serve as intermediates in the Wingless (Wg) signaling pathway, which, like Notch/lin-12, is also responsible for a variety of inductive signaling events. In the non-neuronal 293 cell line, PS1 interacted with beta-catenin, the family member with the greatest homology to Armadillo. Wg and Notch interactions are mediated by the Dishevelled gene, which may form a signaling complex with PS1 and Wg pathway intermediates to regulate the function of the Notch/lin-12 gene.
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PMID:Presenilin 1 interaction in the brain with a novel member of the Armadillo family. 922 6

The catenin ARVCF is a member of the p120(ctn) subfamily of Armadillo proteins. A number of catenins directly bind cadherin cytoplasmic tails, contributing to the modulation of cell-cell adhesion and motility processes. Some catenins, such as beta-catenin (and likely p120(ctn)), have additional roles within signaling pathways regulating gene transcription. We have isolated the Xenopus homolog of human ARVCF. Utilizing the cadherin membrane proximal region known to bind p120(ctn) and delta-catenin, coimmunoprecipitation experiments demonstrate that Xarvcf, likewise, binds cadherin in this region and that corresponding point mutations within conserved residues abrogate the Xarvcf-cadherin association. Western blot analysis of Xarvcf protein across a series of developmental stages reveals changes in protein mobility, likely due to changes in phosphorylation. Xarvcf is a maternally provided transcript and expressed in the embryo throughout all stages of development. Interestingly, Xarvcf mRNA is differentially spliced to produce several isoforms, one of which is developmentally regulated. In common with the putative post-translational modifications of the Xarvcf protein, the presence of alternative splice isoforms suggests that Xarvcf possesses the capacity to effect developmental functions in a regulatable manner.
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PMID:Xarvcf, Xenopus member of the p120 catenin subfamily associating with cadherin juxtamembrane region. 1089 58

Erbin is a recently described member of the LAP (leucine-rich repeat and PDZ domain) protein family. We used a C-terminally displayed phage peptide library to identify optimal ligands for the Erbin PDZ domain. Phage-selected peptides were type 1 PDZ ligands that bound with high affinity and specificity to the Erbin PDZ domain in vitro. These peptides most closely resembled the C-terminal PDZ domain-binding motifs of three p120-related catenins: delta-catenin, ARVCF, and p0071 (DSWV-COOH). Analysis of the interactions of the Erbin PDZ domain with synthetic peptides matching the C termini of ARVCF or delta-catenin also demonstrated specific high affinity binding. We characterized the interactions between the Erbin PDZ domain and both ARVCF and delta-catenin in vitro and in vivo. The Erbin PDZ domain co-localized and coprecipitated with ARVCF or delta-catenin complexed with beta-catenin and E/N-cadherin. Mutagenesis and peptide competition experiments showed that the association of Erbin with the cadherin-catenin complex was mediated by the interaction of its PDZ domain with the C-terminal PDZ domain-binding motifs (DSWV-COOH) of ARVCF and delta-catenin. Finally, we showed that endogenous delta-catenin and Erbin co-localized in and co-immunoprecipitated from neurons. These results suggest that delta-catenin and ARVCF may function to mediate the association of Erbin with the junctional cadherin-catenin complex. They also demonstrate that C-terminal phage-display technology can be used to predict physiologically relevant ligands for PDZ domains.
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PMID:The Erbin PDZ domain binds with high affinity and specificity to the carboxyl termini of delta-catenin and ARVCF. 1182 34

Homophilic cell adhesion mediated by classical cadherins is important for many developmental processes. Proteins that interact with the cytoplasmic domain of cadherin, in particular the catenins, are thought to regulate the strength and possibly the dynamics of adhesion. beta-catenin links cadherin to the actin cytoskeleton via alpha-catenin. The role of p120/delta-catenin proteins in regulating cadherin function is less clear. Both beta-catenin and p120/delta-catenin are conserved in Drosophila. Here, we address the importance of cadherin-catenin interactions in vivo, using mutant variants of Drosophila epithelial cadherin (DE-cadherin) that are selectively defective in p120ctn (DE-cadherin-AAA) or beta-catenin-armadillo (DE-cadherin-Delta beta) interactions. We have analyzed the ability of these proteins to substitute for endogenous DE-cadherin activity in multiple cadherin-dependent processes during Drosophila development and oogenesis; epithelial integrity, follicle cell sorting, oocyte positioning, as well as the dynamic adhesion required for border cell migration. As expected, DE-cadherin-Delta beta did not substitute for DE-cadherin in these processes, although it retained some residual activity. Surprisingly, DE-cadherin-AAA was able to substitute for the wild-type protein in all contexts with no detectable perturbations. Thus, interaction with p120/delta-catenin does not appear to be required for DE-cadherin function in vivo.
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PMID:Binding site for p120/delta-catenin is not required for Drosophila E-cadherin function in vivo. 1255 56

p120-catenin stabilizes epithelial cadherin (E-cadherin) in SW48 cells, but the mechanism has not been established. Here, we show that p120 acts at the cell surface to control cadherin turnover, thereby regulating cadherin levels. p120 knockdown by siRNA expression resulted in dose-dependent elimination of epithelial, placental, neuronal, and vascular endothelial cadherins, and complete loss of cell-cell adhesion. ARVCF and delta-catenin were functionally redundant, suggesting that proper cadherin-dependent adhesion requires the presence of at least one p120 family member. The data reveal a core function of p120 in cadherin complexes, and strongly predict a dose-dependent loss of E-cadherin in tumors that partially or completely down-regulate p120.
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PMID:A core function for p120-catenin in cadherin turnover. 1461 49

Delta-catenin (delta-catenin) is a neuron-specific catenin, which has been implicated in adhesion and dendritic branching. Moreover, deletions of delta-catenin correlate with the severity of mental retardation in Cri-du-Chat syndrome (CDCS), which may account for 1% of all mentally retarded individuals. Interestingly, delta-catenin was first identified through its interaction with Presenilin-1 (PS1), the molecule most frequently mutated in familial Alzheimer's Disease (FAD). We investigated whether deletion of delta-catenin would be sufficient to cause cognitive dysfunction by generating mice with a targeted mutation of the delta-catenin gene (delta-cat(-/-)). We observed that delta-cat(-/-) animals are viable and have severe impairments in cognitive function. Furthermore, mutant mice display a range of abnormalities in hippocampal short-term and long-term synaptic plasticity. Also, N-cadherin and PSD-95, two proteins that interact with delta-catenin, are significantly reduced in mutant mice. These deficits are severe but specific because delta-cat(-/-) mice display a variety of normal behaviors, exhibit normal baseline synaptic transmission, and have normal levels of the synaptic adherens proteins E-cadherin and beta-catenin. These data reveal a critical role for delta-catenin in brain function and may have important implications for understanding mental retardation syndromes such as Cri-du-Chat and neurodegenerative disorders, such as Alzheimer's disease, that are characterized by cognitive decline.
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PMID:Deletion of the neuron-specific protein delta-catenin leads to severe cognitive and synaptic dysfunction. 1538 68

Delta-catenin belongs to the p120-catenin (p120(ctn)) protein family, which is characterized by ten, characteristically spaced Armadillo repeats that bind to the juxtamembrane segment of the classical cadherins. Delta-catenin is the only member of this family that is expressed specifically in neurons, where it binds to PDZ domain proteins in the post-synaptic compartment. As a component of both adherens and synaptic junctions, delta-catenin can link the adherens junction to the synapse and, thereby, coordinate synaptic input with changes in the adherens junction. By virtue of its restriction to the post-synaptic area, delta-catenin creates an asymmetric adherens junction in the region of the synapse. The crucial nature of the specialized function of delta-catenin in neurons is demonstrated by a targeted gene mutation, which causes deficits in learning and in synaptic plasticity. Taken together, recent evidence indicates that delta-catenin is a sensor of synaptic activity and implements activity-related morphological changes at the synapse.
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PMID:Delta-catenin at the synaptic-adherens junction. 1575 81

delta-Catenin, or neural plakophilin-related armadillo protein, is a unique armadillo domain-containing protein in that it is neural-specific and primarily expressed in the brain. However, our recent analysis of the human genome revealed a consistent association of delta-catenin messenger RNA sequences with malignant cells, although the significance of these findings was unclear. In this study, we report that a number of delta-catenin epitopes were expressed in human prostate cancer cells. Western blot and tissue microarray revealed a close association between increased delta-catenin expression and human primary prostatic adenocarcinomas. The analyses of 90 human prostate cancer and 90 benign prostate tissue samples demonstrated that an estimated 85% of prostatic adenocarcinomas showed enhanced delta-catenin immunoreactivity. delta-Catenin expression increased with prognostically significant increased Gleason scores. By analyzing the same tumor cell clusters using consecutive sections, we showed that an increased delta-catenin immunoreactivity was accompanied by the down-regulation and redistribution of E-cadherin and p120ctn, major cell junction proteins whose inactivation is frequently associated with cancer progression. Furthermore, overexpression of delta-catenin in tumorigenic CWR-R1 cells that are derived from human prostate cancer xenograft resulted in reduced immunoreactivity for E-cadherin and p120ctn at the cell-cell junction. This is the first study comparing overexpression of delta-catenin with the E-cadherin/catenin system in cancer and shows that delta-catenin may be intimately involved in regulating E-cadherin/p120ctn cell-cell adhesion in prostate cancer progression.
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PMID:Increased expression of delta-catenin/neural plakophilin-related armadillo protein is associated with the down-regulation and redistribution of E-cadherin and p120ctn in human prostate cancer. 1622 2

The LAP [leucine-rich and postsynaptic density-95/Discs large/zona occludens-1 (PDZ)] protein erbin and delta-catenin, a component of the cadherin-catenin cell adhesion complex, are highly expressed in neurons and associate through PDZ-mediated interaction, but have incompletely characterized neuronal functions. We show that short hairpin RNA-mediated knockdown of erbin and knockdown or genetic ablation of delta-catenin severely impaired dendritic morphogenesis in hippocampal neurons. Simultaneous loss of erbin and delta-catenin does not enhance severity of this phenotype. The dendritic phenotype observed after erbin depletion is rescued by overexpression of delta-catenin and requires a domain in delta-catenin that has been shown to regulate dendritic branching. Knockdown of delta-catenin cannot be rescued by overexpression of erbin, indicating that erbin is upstream of delta-catenin. delta-Catenin-null neurons have no alterations in global levels of active Rac1/RhoA. Knockdown of erbin results in alterations in localization of delta-catenin. These results suggest a critical role for erbin in regulating dendritic morphogenesis by maintaining appropriate localization of delta-catenin.
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PMID:Erbin controls dendritic morphogenesis by regulating localization of delta-catenin. 1861 73

delta-Catenin is a member of the p120-catenin subfamily of armadillo proteins. Here, we describe distinctive features of delta-catenin localization and its association with E-cadherin in HEK293 epithelial cells. In HEK293 cells maintained in low cell densities, approximately 15% of cells overexpressing delta-catenin showed dendrite-like process formation, but there was no detectable change in RhoA activity. In addition, delta-catenin was localized mainly in the cytoplasm and was associated with p190RhoGEF. However, at high cell densities, delta-catenin localization was shifted to the plasma membrane. The association of delta-catenin with E-cadherin was strengthened, whereas its interaction with p190RhoGEF was weakened. In mouse embryonic fibroblast cell, ectopic expression of E-cadherin decreased the effect of delta-catenin on the reduction of RhoA activity as well as on dendrite-like process formation. These results suggest that delta-catenin is more dominantly bound to E-cadherin than to p190RhoGEF, and that delta-catenin's function is dependent on its cellular binding partner.
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PMID:E-Cadherin negatively modulates delta-catenin-induced morphological changes and RhoA activity reduction by competing with p190RhoGEF for delta-catenin. 1893 28


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