CTNND1

CTNND1, encoding the protein p120 catenin (p120ctn), is a gene in humans that encodes a cytoplasmic and membrane-associated protein of the catenin family. p120 catenin associates with classical cadherins at adherens junctions, most notably E-cadherin, stabilizing them at the cell surface and regulating cell-cell adhesion. Loss of p120 catenin from the cadherin complex can promote cadherin endocytosis and weaken cell adhesion, impacting tissue architecture during development and tumor progression.

Beyond its adhesive role, CTNND1 participates in signaling to regulate the actin cytoskeleton. Through interactions with Rho family GTPases and regulators such as p190RhoGAP, p120 catenin modulates RhoA, Rac1, and Cdc42 activity, influencing cell motility, shape, and junction dynamics. It can also shuttle to the nucleus, where it binds transcriptional regulators such as Kaiso and modulates gene expression, linking cell adhesion to transcriptional programs.

CTNND1 produces multiple isoforms by alternative splicing, with distinct tissue distributions and functions. In development, proper CTNND1 function is important for epithelial integrity and morphogenesis; experimentally, CTNND1 disruption can cause defects in model organisms.

Clinically, altered CTNND1 expression and localization have been reported in cancers and other diseases, and germline or mosaic alterations have been described in case reports of developmental disorders, underscoring the gene's role in adhesion, signaling, and development.