alpha-catenin binding domain found in catenin beta-1 (CTNNB1), catenin gamma (CTNNG) and similar proteins
This family includes alpha-catenin binding domain found in catenin beta-1 (CTNNB1), catenin gamma (CTNNG), as well as Drosophila melanogaster armadillo segment polarity protein (dArm). CTNNB1, also called beta-catenin, is a key downstream component of the canonical Wnt signaling pathway. It is involved in the regulation of cell adhesion, as component of an E-cadherin:catenin adhesion complex. It acts as a negative regulator of centrosome cohesion. It is involved in the CDK2/PTPN6/CTNNB1/CEACAM1 pathway of insulin internalization. It blocks anoikis of malignant kidney and intestinal epithelial cells, and promotes their anchorage-independent growth by down-regulating DAPK2. It disrupts PML function and PML-NB formation by inhibiting RANBP2-mediated sumoylation of PML. CTNNG, also called junction plakoglobin (JUP), or desmoplakin III, or desmoplakin-3 (DP3), is a common junctional plaque protein. The membrane-associated plaques are architectural elements in an important strategic position to influence the arrangement and function of both the cytoskeleton and the cells within the tissue. The presence of plakoglobin in both the desmosomes and in the intermediate junctions suggests that it plays a central role in the structure and function of submembranous plaques. CTNNG acts as a substrate for VE-PTP and is required to stimulate VE-cadherin function in endothelial cells. It can replace beta-catenin in E-cadherin/catenin adhesion complexes which are proposed to couple cadherins to the actin cytoskeleton. dArm, which shows high sequence similarity with CTNNB1, is a Drosophila catenin that plays a role during central nervous system development. It can associate with alpha-catenin. Its neural isoform may associate with CadN and participate in the transmission of developmental information. Its cytoplasmic isoform accumulates through Wingless (Wg) signaling; arm function in Wg signal transduction is required early in development for determination of neuroblast fate. Arm and Abl proteins function cooperatively at adherens junctions in both the CNS and epidermis. This model corresponds to a small region at the C-termini of dArm, CTNNB1 and CTNNG; in CTNNB1, this region is responsible for alpha-catenin binding.
Jiyao W et al.(2023). "The conserved domain database in 2023.",