DNA contains 57419 bp composed of 21 exons, 19 of which are coding exons.

Alternative transcription produces several distinct mRNAs ranging from 5676 bp to 6329 bp, transcribed in centromeric to telomeric orientation, with open reading frames ranging from 2802 bp to 2904 bp.

None.

This gene encodes a member of the Armadillo (Arm) family of proteins, which function in cell-cell adhesion and signal transduction, and is the prototype for a subfamily of proteins that includes p120-catenin (hereafter p120), delta-catenin, p0071, and plakophilins 1-3 (PKP1, PKP2, PKP3). CTNND1/p120 has four distinct translation start codons (isoforms 1-4) and three alternatively spliced exons (A, B, and C), potentially resulting in 32 isoforms as products of alternative splicing. A coiled-coil domain is present in the extreme amino-terminus of the long-isoform (isoform-1), and an amino terminal phosphorylation domain is present in all but the shortest isoform (isoform-4). All p120 isoforms contain a central Arm domain consisting of nine Arm repeats. p120 has been shown to be post-translationally modified by phosphorylation on tyrosine, serine, and threonine residues, as well as by cleavage by the protease calpain. Phosphorylation of p120 may be regulated in part via interactions with non-receptor tyrosine kinases, (including Fer, Fyn, and Yes) and protein tyrosine phosphatases (including PTPmu, SHP-1, and DEP-1).

p120 isoforms have been detected in all tissues examined, although cells of epithelial origin tend to predominantly express isoform 3, whereas motile, fibroblastoid cells often express isoform 1.

Cell-cell junctions (bound to cadherin molecules), cytoplasm, and nucleus.

CTNND1/p120 was originally identified as a substrate for the Src oncogene and for various receptor tyrosine kinases, though its most prominent role is in stabilizing adherens junctions. Via its Arm domain, p120 binds to the juxtamembrane region of the cytoplasmic tails of type I and II cadherins. Upon removal of p120, by either gene knock-out or shRNA-mediated knock-down, adherens junction components, namely cadherin, beta-catenin, and alpha-catenin, are internalized and rapidly degraded. p120 also likely participates in the rearrangement of the actin cytoskeleton via regulation of Rho family GTPases, and p120 may also influence gene expression via its interaction in the nucleus and cytoplasm with the transcriptional repressor Kaiso.

Pan troglodytes - CTNND1; Canis lupus familiaris - CTNND1; Bos taurus - CTNND1; Mus musculus - Ctnnd1; Rattus norvegicus - Ctnnd1; Gallus gallus - RCJMB04_21j12; Danio rerio - LOC556726.

While p120 is frequently decreased in a wide variety of cancers, the only mutated p120 identified to date is found in colonic SW48 cells. In these cells, a heterozygous nonsense mutation in exon 7 at nucleotide 1908 (C to T) yields a premature stop codon that truncates the protein in the third ARM repeat. Several other cDNA abnormalities, including deletion of exon 17, retention of intron 19, or retention of both introns 19 and 20, were also identified in both p120 alleles in these cells, resulting in premature stop codons that eliminate the normal p120 COOH terminus.