Catenin alpha-1

Catenin alpha-1 (CTNNA1) is a cytoplasmic protein that associates with the intracellular domains of cadherins, particularly E- and N-cadherins, to link them to the actin cytoskeleton at adherens junctions (UniProt: P35221). The protein regulates actin filament dynamics and may control cell differentiation through its interactions with transcriptional regulators YAP1 and TAZ. While CTNNA1 is primarily associated with ocular disease (macular dystrophy, patterned, 2), it plays a fundamental role in cellular adhesion and cytoskeletal organization.

In Alzheimer's Disease, CTNNA1 is upregulated in post-mortem brain tissue compared to age-matched controls (Chaparral AD proteomics). The protein shows an average log2 fold-change of +0.6375 across analyzed subcellular fractions in a TMT-labeled proteomic study of four brain compartments. This upregulation may reflect compensatory responses to synaptic dysfunction or changes in cell-adhesion architecture that occur during neurodegeneration, though the functional significance of increased CTNNA1 in AD pathology requires further investigation.