B-Myc Background Information The Myc family of genes includes five functional members, including c-Myc, L-Myc, N-Myc, B-Myc, and S-Myc. The B-Myc gene maps to the rat chromosome 3 and encodes a 178 amino acid protein. B-Myc is a short-lived nuclear protein which is phosphorylated on residues Ser 60 and Ser 68. B-Myc-specific mRNA is most higly expressed in rat brain and closely resembles the expression pattern of c-Myc. The B-Myc protein is primarily expressed in hormonally-controlled tissues, with the highest level of expression in the epididymis. B-Myc shows extensive homology to c-Myc in the N-terminal region, which contains a transcriptional activation domain. B-Myc inhibits both neoplastic transformation and transcriptionl activation by c-Myc, and therefore may function as an inhibitor of cellular proliferation.
