Catenin alpha-2 (CTNNA2) Isoform 5

Catenin alpha-2 is an adherens junction protein encoded by CTNNA2 (UniProt: P26232-5). As a member of the catenin family, it functions in cell-cell adhesion by linking cadherins to the actin cytoskeleton, playing roles in maintaining epithelial and neuronal tissue integrity.

CTNNA2 is expressed across multiple tissues and is particularly relevant in the nervous system, where adherens junctions are critical for synaptic stability and neuronal organization. The protein has been implicated in neurodevelopmental processes and neural circuit formation.

In Alzheimer's Disease, CTNNA2 isoform 5 is significantly downregulated in post-mortem AD brain tissue compared to age-matched controls (mean log2 fold-change: −0.75; Chaparral AD proteomics). This downregulation was detected via TMT-labeled quantitative proteomics across subcellular fractions, suggesting potential disruption of adherens junction integrity as a feature of AD pathology.