High impact information on alpha-Cat

• We find that in zygotic shg nulls the level of Dalpha-catenin and Armadillo at adherens junctions is dramatically reduced, surprisingly also in epithelia that differentiate normally and possess a zonula adherens [1].
• Cadherin-catenin complexes, localized to adherens junctions, are essential for cell-cell adhesion [2].
• Finally, loss of Abl reduces Arm and alpha-catenin accumulation in adherens junctions, while having little or no effect on other components of the cytoskeleton or cell polarity machinery [3].
• In this paper, we show that the basal accumulation of Arm colocalizes with DE-cadherin and Dalpha-catenin, and corresponds to a region of tight membrane association, which we refer to as the basal junction [4].
• This region interacts with C-cadherin and with the APC tumor suppressor protein, but not with alpha-catenin, that requires the amino-terminal region of beta-catenin to bind to the complex [5].

Biological context of alpha-Cat

• We mapped the binding sites for DE-cadherin and alpha-catenin [6].
• Single amino acid substitutions in proteins of the armadillo gene family abolish their binding to alpha-catenin [7].
• The catenin p120(ctn) interacts with Kaiso, a novel BTB/POZ domain zinc finger transcription factor [8].
• Removal of PKG's head and first ARM repeat, which includes its alpha-catenin binding site, resulted in a polypeptide that, when expressed in the embryo, generated alpha dramatic cell adhesion defect [9].

Anatomical context of alpha-Cat

• Here we show interactions between Drosophila Rho1 and the adherens junction components alpha-catenin and p120(ctn) [10].
• Genes such as egalitarian, Bicaudal D, stonewall, and encore are important for oocyte determination, while differential adhesion between the oocyte and its surrounding prefollicle cells, as mediated by armadillo, alpha-catenin, shotgun, and the spindle genes, is crucial for oocyte translocation [11].
• In this study, we constructed Dalpha-catenin fused with a green fluorescent protein (Dalpha-catenin-GFP), and found that it targeted apically located AJ-based contacts but not other lateral contacts in epithelial cells of living Drosophila embryos [12].
• Roles of Armadillo, a Drosophila catenin, during central nervous system development [13].
• Using Xenopus embryos we show by expression of murine p120cas1B (mp120cas1B) in ventral blastomeres that this catenin cannot replace beta-catenin function in dorsal axis formation [14].

Associations of alpha-Cat with chemical compounds

• A monoclonal antibody to Drosophila alpha-catenin (D alpha-catenin) copurifies a 150-kDa glycoprotein (gp150) along with the alpha-catenin [15].
• Co-immunoprecipitation assays have demonstrated that tyrosine hyper-phosphorylation does not cause the dissociation of Drosophila (D)E-cadherin and alpha-catenin or Armadillo, suggesting that abrogation in adhesion is most likely attributable to the detachment of actin-associated proteins from the CCC [16].

Physical interactions of alpha-Cat

• The alpha-catenin binding site is fully encoded within exon 3 of plakoglobin but only partially represented in Armadillo repeat 1 [7].

Other interactions of alpha-Cat

• Therefore, we utilized the two hybrid system and confirmatory co-immunoprecipitations to identify a novel catenin, termed gamma-catenin, which interacts with PS1 and is principally expressed in brain [17].

Analytical, diagnostic and therapeutic context of alpha-Cat

• Site-directed mutagenesis identified residues in the alpha-catenin binding site indispensable for binding in vitro [7].

References