Key dowstream component of the canonical Wnt signaling pathway. In the absence of Wnt, forms a complex with AXIN1, AXIN2, APC, CSNK1A1 and GSK3B that promotes phosphorylation on N-terminal Ser and Thr residues and ubiquitination of CTNNB1 via BTRC and its subsequent degradation by the proteasome. In the presence of Wnt ligand, CTNNB1 is not ubiquitinated and accumulates in the nucleus, where it acts as a coactivator for transcription factors of the TCF/LEF family, leading to activate Wnt responsive genes. Involved in the regulation of cell adhesion. Acts as a negative regulator of centrosome cohesion. Involved in the CDK2/PTPN6/CTNNB1/CEACAM1 pathway of insulin internalization.
Specificity
Natural and recombinant Bovine Catenin beta-1
Subcellular Location
Cytoplasm Cytoplasm cytoskeleton Nucleus Cell junction adherens junction Cell junction Cell membrane Cytoplasm cytoskeleton centrosome Cytoplasm cytoskeleton spindle pole Cytoplasmic when it is unstabilized (high level of phosphorylation) or bound to CDH1. Translocates to the nucleus when it is stabilized (low level of phosphorylation). Interaction with GLIS2 and MUC1 promotes nuclear translocation. Interaction with EMD inhibits nuclear localization. The majority of beta-catenin is localized to the cell membrane. In interphase, colocalizes with CROCC between CEP250 puncta at the proximal end of centrioles, and this localization is dependent on CROCC and CEP250. In mitosis, when NEK2 activity increases, it localizes to centrosomes at spindle poles independent of CROCC. Co-localizes with CDK5 in the cell-cell contacts and plasma membrane of undifferentiated and differentiated neuroblastoma cells.
Two separate complex-associated pools are found in the cytoplasm. The majority is present as component of an E-cadherin/ catenin adhesion complex composed of at least E-cadherin/CDH1 and beta-catenin/CTNNB1, and possibly alpha-catenin/CTNNA1; the complex is located to adherens junctions. The stable association of CTNNA1 is controversial as CTNNA1 was shown not to bind to F-actin when assembled in the complex. Alternatively, the CTNNA1-containing complex may be linked to F-actin by other proteins such as LIMA1. Another cytoplasmic pool is part of a large complex containing AXIN1, AXIN2, APC, CSNK1A1 and GSK3B that promotes phosphorylation on N-terminal Ser and Thr residues and ubiquitination of CTNNB1 via BTRC and its subsequent degradation by the proteasome. Wnt-dependent activation of DVL antagonizes the action of GSK3B. When GSK3B activity is inhibited the complex dissociates, CTNNB1 is dephosphorylated and is no longer targeted for destruction. The stabilized protein translocates to the nucleus, where it binds TCF/LEF-1 family members, TBP, BCL9 and possibly also RUVBL1 and CHD8. Binds CTNNBIP and EP300. CTNNB1 forms a ternary complex with LEF1 and EP300 that is disrupted by CTNNBIP1 binding (By similarity). Interacts with TAX1BP3 (via the PDZ domain); this interaction inhibits the transcriptional activity of CTNNB1. Interacts with AJAP1, BAIAP1, CARM1, CTNNA3, CXADR and PCDH11Y. Binds SLC9A3R1. Interacts with GLIS2 and SLC30A9. Interacts with XIRP1 and MUC1. Interacts with PTPRU (via the cytoplasmic juxtamembrane domain) and with EMD. Interacts with SCRIB. Interacts with TNIK. Interacts with SESTD1 and TRPC4. Interacts directly with AXIN1; the interaction is regulated by CDK2 phosphorylation of AXIN1. Interacts with CAV1. Interacts with TRPV4. The TRPV4 and CTNNB1 complex can interact with CDH1. Interacts with VCL. Interacts with PTPRJ (By similarity). Interacts with PKT7 (By similarity). Interacts with FAT1 (via the cytoplasmic domain) (By similarity). Interacts with NANOS1 (By similarity). Interacts with NEK2, CDK2 and CDK5.