Extracellular Ca²⁺ induces PKP1 translocation from nucleus to plasma membrane.

<p>A, Cell proliferation was analyzed using a CCK-8 assay after stimulation with 100 ng/ml NT-4 or 1.5 mM Ca²⁺. B, AMBN expression was analyzed by qRT-PCR after stimulation with 100 ng/ml NT-4 or 1.5 mM Ca²⁺ (*P <0.01). Error bars represent the mean ± S.D. C, CLDE cells were cultured with 1.5 mM Ca²⁺ for 1 week, then the expressions of PKP1, ZO-1, E-cadherin, β-catenin, AMBN, and Sox2 were assessed by western blotting. GAPDH was used as a loading control. D. CLDE cells were cultured with or without Ca²⁺ for 48 h. Expressions of PKP1 (green, center panel) and transfected PKP1-EmGFP were detected by immunocytochemistry, and visualized by confocal microscopy. Nuclei were stained with DAPI (blue).