CTNNBL is a family of eukaryotic nuclear proteins of the catenin-beta-like 1 type that contain an armadillo motif. A human nuclear protein with this domain (Swiss:Q8WYA6) is thought to have a role in apoptosis [1]. The interaction of CTNNBL1 with its known partners (the Prp19-CDC5L complex and AID) is mediated by recognition of NLS (nuclear localisation signal) motifs. The RNA-splicing factor Prp31 is also an interactor, with recognition also occurring through the NLS. CTNNBL1 uses its central armadillo (ARM) domain to bind NLS-containing partners [2,3].

1: Sequence, gene structure, and expression pattern of CTNNBL1, a minor-class intron-containing gene--evidence for a role in apoptosis. Jabbour L, Welter JF, Kollar J, Hering TM; Genomics 2003;81:292-303. PMID:12659813

2: Armadillo-repeat protein functions: questions for little creatures. Tewari R, Bailes E, Bunting KA, Coates JC; Trends Cell Biol. 2010;20:470-481. PMID:20688255

3: CTNNBL1 is a novel nuclear localization sequence-binding protein that recognizes RNA-splicing factors CDC5L and Prp31. Ganesh K, Adam S, Taylor B, Simpson P, Rada C, Neuberger M; J Biol Chem. 2011;286:17091-17102. PMID:21385873