p-B-Myb Anticuerpo(Thr 490): sc-20209

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A member of the myb proto-oncogene family, B-Myb is a cell cycle-regulated transcription factor that is essential for the transition from G1 to S phase. This nuclear protein becomes phosphorylated at the onset of S phase by the cyclin A/Cdk2 complex. Ten phosphorylation sites have been identified and all sites were on either serine or threonine residues that were followed by a proline residue, suggesting that phosphorylation is due to a proline-directed kinase. Transactivation properties of B-Myb are apparently dependent upon the protein’s hyperphosphorylation. Several phosphorylation sites, including threonine 447, threonine 490, threonine 497 and serine 581, are located near the protein’s C-terminus. Phosphorylation of these C-terminal residues plays a critical role in enhancing the transcriptional activity of B-Myb. Poly(ADP-ribose) polymerase (PARP), which has a role in cellular proliferation, binds to B-Myb and thus enhances B-Myb transactivation. PARP is a B-Myb co-factor and promotes phosphorylation of B-Myb by the Cyclin/Cdk2 complex.