Phospho-c-Myb (Ser11) (F6D5K) Rabbit Monoclonal Antibody #44427

c-Myb is a transcriptional activator that specifically recognizes the sequence 5'-YAAC[GT]G-3'. It is expressed in hematopoietic progenitor cells, where it plays an important role in the control of proliferation and differentiation (1-3). c-Myb is required for transcription of genes involved in self-renewal of intestinal stem cells. Importantly, c-Myb regulates expression of Lgr5, a protein expressed in putative intestinal stem cells that give rise to all cell lineages of small intestinal crypts (4). c-Myb is reported to be expressed in colon crypt cells and in human colorectal cancer cell lines (5,6). Research has shown that MYB gene translocations and copy number alterations are found in several leukemias, breast cancer, and other solid tumors (7,8).

The c-Myb DNA-binding domain (DBD) can be phosphorylated at Ser11/Ser12 by casein kinase 2 (CK2), which similarly phosphorylates a-Myb and b-Myb, while it is uniquely phosphorylated by protein kinase A (PKA) (9,10). Ser11/Ser12 phosphorylation reduces c-Myb transactivation to target genes and alters its interaction with the cooperative transcription factor C/EBP beta (10). These inhibitory sites are frequently deleted in c-Myb-driven cancers (11), and c-Myb isoforms lacking the DBD are aberrantly expressed in adenoid cystic carcinomas through an alternative MYB promoter (12).