The Popdc gene family in the rat: Molecular cloning, characterization and expression analysis in the heart and cultured cardiomyocytes

Three Popeye domain-containing (Popdc 1–3) family-members are known in vertebrates. Their exact function is as yet unknown although involvement in cell adhesion has been suggested. We report herein sequencing of the rat Popdc 1–3 cDNAs that show high homology to other vertebrate orthologs and are expressed primarily in the heart and skeletal muscles. Popdc2 splice variants were identified, with Popdc2C showing a distinctive age-dependent decline. In isolated cardiomyocytes, Popdc genes were negatively regulated by serum, an effect that was reversed by EGFR-kinase inhibition, suggesting an EGFR-dependent modulation of Popdc gene expression.