delta2catenin

Delta-2-catenin, encoded by the CTNND2 gene, is a member of the p120-catenin family of armadillo-repeat proteins. It is predominantly expressed in the brain, with notable presence in cortical and hippocampal neurons, and localizes to the cytoplasm and to adherens junction complexes in neurons.

As part of the cadherin–catenin system, delta-2-catenin associates with classical cadherins at adherens junctions and helps regulate cadherin stability and cell–cell adhesion. In the nervous system, it plays a role in dendritic growth, arborization, and spine maturation, contributing to synaptic development and plasticity. Through interactions that influence the actin cytoskeleton and signaling pathways, delta-2-catenin can modulate Rho family GTPase activity, affecting neurite outgrowth and neuronal connectivity.

Delta-2-catenin can interact with scaffolding proteins such as AF-6/afadin and other components of the synaptic adhesion complex, supporting junctional organization and signal transduction at developing and mature synapses. Its function intersects with neuronal activity-dependent signaling, linking cell adhesion to cytoskeletal remodeling.

Genetic alterations involving CTNND2, including deletions or loss-of-function variants, have been associated with neurodevelopmental disorders such as intellectual disability and autism spectrum disorders, though phenotypes can be variable. Experimental models with reduced delta-2-catenin show impaired dendritic morphology and synaptic function, underscoring its importance in brain development and neuronal connectivity. Delta-2-catenin is evolutionarily conserved among vertebrates and exemplifies how adhesion molecules coordinate neuronal structure and signaling.