| The Myb family of transcription factors regulate differentiation and cellular growth through binding to promoters with the consensus sequence 5-AAC(G/T)G-3 and transactivating gene expression. The proto-oncogene c-Myb is the cellular homolog of the leukemogenic avian retroviral protein v-Myc, and c-Myc is expressed predominantly in immature and rapidly dividing hematopoietic cells. Additional members of the family include B-Myb, a 110 kDa protein that is expressed in a wide variety of proliferating cells at the G1 to S phase transition, and A-Myb, which is expressed in reproductive tissues, some neural cells and a subset of normal and neoplastic B lymphocytes. Transactivation properties of B-Myb are apparently dependent upon the proteins hyperphosphorylation at several C-terminal residues, including Thr 447, Thr 490, Thr 497 and Ser 581. Dmp1 is related to the Myb family and also functions as a transcriptional activator. Dmp1 contains three tandem Myb repeats and is a putative substrate for cyclin D-dependent kinase. |
