Alpha-T-catenin is expressed in peripheral nerves as a constituent of Schwann cell adherens junctions

Abstract

The adherens junction component, alpha-T-catenin (Tcat) is an established contributor to cardiomyocyte junction structure and function, but recent genomic studies link CTNNA3 polymorphisms to diseases with no clear cardiac underpinning, including asthma, autism and multiple sclerosis, suggesting causal contributions from a different cell-type. We show Ctnna3 mRNA is highly expressed in peripheral nerves (e.g., vagus and sciatic), where Tcat protein enriches at paranodes and myelin incisure adherens junctions of Schwann cells. We validate Tcat immunodetection specificity using a new Ctnna3-knockout fluorescence reporter mouse line yet find no obvious Schwann cell loss-of-function morphology at the light microscopic level. CTNNA3/Ctnna3 mRNA is also abundantly detected in oligodendrocytes of the central nervous system via public databases, supporting a general role for Tcat in these unique cell-cell junctions. These data suggest that the wide range of diseases linked to CTNNA3 may be through its role in maintaining neuroglial functions of central and peripheral nervous systems.