Proteins that are associated with the cytoplasmic domain of adhesion molecules such as cadherins and link them to the cytoskeleton. A second role is in regulating transcription factors. α-Catenin (906 aa) is a vinculin-related protein involved in adherens junction-mediated intercellular adhesion; abnormalities are associated with cancer invasion and metastasis. β-Catenin (781 aa) binds E-cadherin and N-cadherin. A second pool of β-catenin is cytoplasmic and coimmunoprecipitates with the adenomatous polyposis coli (APC) tumour suppressor protein, interacts with Tcf and Lef transcription factors, and is an essential member of the Wingless wnt signal transduction pathway. Ubiquitination of β-catenin is greatly reduced in Wnt-expressing cells. See dapper. Mutations in catenin B1 are associated with colorectal cancer, ovarian and prostate carcinomas, hepatoblastoma, hepatocellular carcinoma, pilomatrixoma, and medulloblastoma. γ-Catenin (desmoplakin-3, plakoglobin, 745 aa), is a major component of desmosomes. Mutations are associated with Naxos disease and familial arrhythmogenic right ventricular dysplasia type 12. δ-Catenin-1 (p120, p120ctn, cadherin-associated src substrate, 938 aa) is involved in cell–cell adhesion complexes together with E-*cadherin, α-, β-, and γ-catenins. It is tyrosine-phosphorylated by ligand-activated EGF-, PDGF-, and CSF1-receptors and loss of expression is associated with some invasive tumours. δ-Catenin-2 (neural plakophilin-related armadillo repeat protein, δ-catenin, neurojungin, CTNND2, 1225 aa) is found in neural tissues and, together with kaiso and myogenic transcription factors, regulates synapse-specific transcription of rapsyn. Hemizygosity of the gene is associated with cri-du-chat syndrome.
Subjects: Medicine and health