Differential expression of alpha-E-catenin and alpha-N-catenin in the developing cerebral cortex

Alpha (α) catenin proteins can regulate both cell adhesion and cell proliferation. Here, we characterize the expression of two forms of α-catenin, αE-catenin and αN-catenin, in the developing cerebral cortex and primary cortical cultures. In situ hybridization and immunofluorescence studies reveal that αE-catenin is highly expressed in neuroepithelial precursor cells in the developing cortical ventricular zone, with markedly reduced expression in the cortical plate; in contrast, αN-catenin expression is low in the ventricular zone and high in the developing cortical plate. In the ventricular zone, immunoreactivity for both αE-catenin and αN-catenin is enriched in rings at the lumenal surface, reflecting localization at adherens junctions together with β-catenin. Expression of αE-catenin in primary cortical precursor cultures is initially robust, but declines as neural precursors differentiate into neurons. Reflecting its expression pattern in vivo, αN-catenin is expressed in both neural precursors as well in neurons differentiated in culture. These differential expression patterns of αE-catenin and αN-catenin suggest both distinct and overlapping functions during cortical development.