The Beta-catenin-like protein 1 (CTNNBL1) contains an acidic domain, a putative bipartite nuclear localization signal, a nuclear export signal, a leucine-isoleucine zipper, and phosphorylation motifs, as well as Armadillo/beta-catenin-like repeats. Transient expression of CTNNBL1 resulted in translocation to the nucleus and apoptosis, suggesting it may be involved in the apoptotic pathway. CTNNBL1 interacts with the Prp19 complex of the spliceosome and the Ig class switching enzyme activation-induced deaminase (AID) and had been suggested to play a role in antibody-diversification and class switching, but recent studies have shown CTNNBL1 to be dispensable for Ig class switch recombination. Other studies have identified CTTNBL1 as a novel gene for obesity.