CTNNB1/A0112

Catenin, beta 1 (CTNNB1), also known as A0112, is a cadherin-associated protein.

Catenin, beta 1 (CTNNB1), also known as A0112, is a cadherin-associated protein. It belongs to the family of beta-catenin that functions as adherens junction proteins. CTNNB1 is involved in intercellular adhesion and Wnt signaling, and is responsible for the establishment and maintenance of epithelial layer. CTNNB1 is found in a cytoplasmic complex consists of presenilin/cadherin/catenin. Presenilin is a protein associated with Alzheimer’s disease. CTNNB1 is phosphorylated by various proteins including glycogen synthase kinase 3 (GSK3). CTNNB1 is mainly expressed in hair follicle cells and in the colon. CTNNB1 mutations in humans are associated with tumors such as medulloblastoma (an invasive tumor of the cerebellum) and pilomatrixoma (a common skin tumor). Multiple CTNNB1 mutant mouse models have been developed, which give various proliferation defects including intestinal polyps, brain and spinal cord size anomalies. Transgenic mice over-expressing a N-terminal truncated form of CTNNB1 have enlarged brains with an increased cerebral cortical surface area, probably due to an expansion of the neuroepithelial precursor population. This suggests that CTNNB1 plays a role in neuronal development. Homozygous null mice embryos die by E7, and show anterior-posterior axis formation anomalies.