The disclosure relates to isolated polynucleotides and purified polypeptides of the Neu family of proteins, which have been shown to demonstrate transcriptional regulatory activity. For example, the purified polynucleotide can encode a Neu polypeptide, wherein the Neu polypeptide comprises at least one neuralized homology repeat domain and a C3HC4 RING-zinc finger domain is disclosed. A purified Neu polypeptide, wherein the Neu polypeptide comprises at least one neuralized homology repeat domain and a C3HC4 RING-zinc finger domain is disclosed. Antibodies capable of specifically binding to the disclosed Neu polypeptides are disclosed. Vectors expressing the disclosed Neu protein coding regions and host cells containing the vectors are disclosed. Methods of making the Neu proteins disclosed are also provided, as are method of identifying binding partners that interact with a Neu protein family member.