Barnikol-Watanabe et al. (1994) isolated a partial NUCB2 cDNA clone. They assembled a full-length clone encoding a deduced 420-amino acid protein, which they called NEFA, with a calculated molecular mass of 48 kD. The protein contains a basic amino acid-rich putative DNA-binding domain with a potential nuclear targeting signal, 2 helix-loop-helix motif regions, 2 concurrent EF-hand motifs, an acidic amino acid region between the EF-hands, and a leucine zipper motif. The protein shares high homology with human NUCB1. Isoelectric focusing demonstrated the presence of NUCB2 on the plasma membrane, in the cytosol, and in the culture supernatant. NUCB2 is a highly charged protein with a relative molecular mass of 55 kD by SDS-PAGE, despite the lack of N- or O-glycosylation sites.