Molecular cloning of human epimorphin: identification of isoforms and their unique properties

Epithelial-mesenchymal interactions are crucial for various epithelial tissue organizations and epimorphin is one of the important signaling molecules from the mesenchyme. The sequence analysis of a human homologue revealed that both of primary and predicted secondary structures of epimorphin are highly conserved among species and this molecule has some isoforms including a putative soluble type. I found that human epimorphins also have a large discrepancy in molecular masses as the case of mouse (around 33kD are predicted by the sequences whereas two protein bands of 60-70kD and 150kD are detected in the cells), and it can be explained, at least in part, by the SDS-resistant complexes formed in the microsomal membranes.