Enables identical protein binding activity. Involved in several processes, including modification of postsynaptic actin cytoskeleton; nervous system development; and prepulse inhibition. Located in several cellular components, including adherens junction; basolateral plasma membrane; and hippocampal mossy fiber to CA3 synapse. Is extrinsic component of postsynaptic membrane and extrinsic component of presynaptic membrane. Is active in parallel fiber to Purkinje cell synapse; postsynaptic density, intracellular component; and presynaptic active zone cytoplasmic component. Is expressed in several structures, including alimentary system; nervous system; reproductive system; respiratory system; and sensory organ. Human ortholog(s) of this gene implicated in complex cortical dysplasia with other brain malformations. Orthologous to human CTNNA2 (catenin alpha 2). [provided by Alliance of Genome Resources, Apr 2022]