Catenin beta-1

Catenin beta-1 (CTNNB1) is a key downstream component of the canonical Wnt signaling pathway that functions as a transcriptional coactivator (UniProt: P35222). In the absence of Wnt ligands, CTNNB1 is phosphorylated and ubiquitinated by a complex including AXIN1, APC, and GSK3B, leading to proteasomal degradation. When Wnt signaling is active, CTNNB1 accumulates in the nucleus and acts as a coactivator for TCF/LEF transcription factors to activate Wnt-responsive genes. The protein also participates in cell adhesion, epithelial-mesenchymal transition, and neurogenesis.

CTNNB1 is involved in multiple cellular and developmental contexts, including centrosome regulation, insulin internalization, and chondrocyte and odontoblast differentiation. Disease associations include colorectal cancer, medulloblastoma, ovarian cancer, and pilomatrixoma, reflecting its role in cell proliferation and cancer pathways.

CTNNB1 carries SFARI classification tags indicating a curated association with autism spectrum disorder (SFARI Cat 1), specifically as a syndromic autism gene. Mutations in CTNNB1 have been linked to neurodevelopmental disorder with spastic diplegia and visual defects (NEDSDV), an autosomal dominant condition characterized by developmental delay, intellectual disability, microcephaly, and spasticity (UniProt: P35222).