Expression of novel DNA-binding protein with zinc finger structure in various tumor cells.

We have isolated from B16 mouse melanoma cells a complementary DNA (Mel-18), whose deduced amino acid sequence possesses a characteristic zinc finger structure. Immunostaining with antibodies raised against partial Mel-18 peptide sequences demonstrated nuclear localization of the gene product. We have also demonstrated that this protein has DNA-binding capacity, and the zinc finger is responsible for the DNA binding. At the transcriptional level the Mel-18 mRNA was detected in all tumor cells examined as well as melanoma cells (ontogenically of neural origin) but was scarcely present in normal tissues except neural organs. The transcript is developmentally regulated. These data suggest that Mel-18 may play a role in transcriptional regulation and also in control of cell proliferation and/or neural cell development.