The vertebrate adhesive junction proteins beta-catenin and plakoglobin and the Drosophila segment polarity gene armadillo form a multigene family with similar properties.
Three proteins identified by quite different criteria in three different systems, the Drosophila segment polarity gene armadillo, the human desmosomal protein plakoglobin, and the Xenopus E-cadherin-associated protein beta-catenin, share amino acid sequence similarity. These findings raise questions about the relationship among the three molecules and their roles in different cell-cell adhesive junctions. We have found that antibodies against the Drosophila segment polarity gene armadillo cross react with a conserved vertebrate protein. This protein is membrane associated, probably via its interaction with a cadherin-like molecule. This cross-reacting protein is the cadherin-associated protein beta-catenin. Using anti-armadillo and antiplakoglobin antibodies, it was shown that beta-catenin and plakoglobin are distinct molecules, which can coexist in the same cell type. Plakoglobin interacts with the desmosomal glycoprotein desmoglein I, and weakly with E-cadherin. Although beta-catenin interacts tightly with E-cadherin, it does not seem to be associated with either desmoglein I or with isolated desmosomes. Anti-armadillo antibodies have been further used to determine the intracellular localization of beta-catenin, and to examine its tissue distribution. The implications of these results for the structure and function of different cell-cell adhesive junctions are discussed.
Peifer
M
M
Department of Biology, University of North Carolina, Chapel Hill 27599.
McCrea
P D
PD
Green
K J
KJ
Wieschaus
E
E
Gumbiner
B M
BM
D000595:Amino Acid Sequence; D000818:Animals; D051186:Armadillo Domain Proteins; D015820:Cadherins / Q000235:genetics* / Q000378:metabolism; D015815:Cell Adhesion Molecules / Q000235:genetics* / Q000276:immunology / Q000378:metabolism; D002460:Cell Line; D003429:Cross Reactions; D003598:Cytoskeletal Proteins / Q000235:genetics* / Q000276:immunology / Q000378:metabolism; D051183:Desmoglein 1; D051182:Desmogleins; D051180:Desmoplakins; D004330:Drosophila / Q000235:genetics*; D029721:Drosophila Proteins; D004591:Electrophoresis, Polyacrylamide Gel; D005455:Fluorescent Antibody Technique; D006801:Humans; D007365:Intercellular Junctions / Q000378:metabolism; D051379:Mice; D008969:Molecular Sequence Data; D005810:Multigene Family; D011506:Proteins / Q000235:genetics* / Q000276:immunology / Q000378:metabolism; D012689:Sequence Homology, Nucleic Acid; D015534:Trans-Activators; D014157:Transcription Factors; D051176:beta Catenin; D051185:gamma Catenin
C495305:ARM protein, Drosophila; D051186:Armadillo Domain Proteins; C495270:CTNNB1 protein, human; C495267:CTNNB1 protein, mouse; D015820:Cadherins; D015815:Cell Adhesion Molecules; D003598:Cytoskeletal Proteins; D051183:Desmoglein 1; D051182:Desmogleins; D051180:Desmoplakins; D029721:Drosophila Proteins; D011506:Proteins; D015534:Trans-Activators; D014157:Transcription Factors; D051176:beta Catenin; D051185:gamma Catenin