Lüscher B, Christenson E, Litchfield D W, Krebs E G, Eisenman R N
Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington 98104.
Nature. 1990 Apr 5;344(6266):517-22. doi: 10.1038/344517a0.
The c-Myb nuclear oncoprotein is phosphorylated in vitro and in vivo at an N-terminal site near its DNA-binding domain by casein kinase II (CK-II) or a CK-II-like activity. This in vitro phosphorylation reversibly inhibits the sequence-specific binding of c-Myb to DNA. The site of this phosphorylation is deleted in nearly all oncogenically activated Myb proteins, resulting in DNA-binding that is independent of CK-II. Because CK-II activity is modulated by growth factors, loss of the site could uncouple c-Myb from its normal physiological regulator.
原癌基因蛋白c-Myb在体外和体内靠近其DNA结合结构域的N端位点被酪蛋白激酶II（CK-II）或类似CK-II的活性磷酸化。这种体外磷酸化可逆地抑制c-Myb与DNA的序列特异性结合。几乎所有致癌激活的Myb蛋白中该磷酸化位点都缺失，导致与DNA的结合独立于CK-II。由于CK-II活性受生长因子调节，该位点的缺失可能使c-Myb与其正常生理调节因子解偶联。
