Bjørling-Poulsen Marina, Siehler Simone, Wiesmüller Lisa, Meek David, Niefind Karsten, Issinger Olaf-Georg
Institut for Biokemi og Molekylaer Biologi, Syddansk Universitet, Odense, Denmark.
Oncogene. 2005 Sep 8;24(40):6194-200. doi: 10.1038/sj.onc.1208762.
The 'regulatory' beta-subunit of protein kinase CK2 has previously been shown to interact with protein kinases such as A-Raf, c-Mos, Lyn and Chk1 in addition to the catalytic subunit of CK2. Sequence alignments suggest that these interactions have a structural basis, and hence other protein kinases harboring corresponding sequences may be potential interaction partners for CK2beta. We show here that Chk2 specifically interacts with CK2beta in vitro and in cultured cells, and that activation of Chk2 leads to a reduction of this interaction. Additionally, we show that the presence of the CK2beta-subunit significantly reduces the Chk2-catalysed phosphorylation of p53 in vitro. These findings support the notion that CK2beta can act as a general modulator of remote docking sites in protein kinase--substrate interactions.
蛋白激酶CK2的“调节性”β亚基此前已被证明，除了能与CK2的催化亚基相互作用外，还能与A-Raf、c-Mos、Lyn和Chk1等蛋白激酶相互作用。序列比对表明，这些相互作用具有结构基础，因此，含有相应序列的其他蛋白激酶可能是CK2β潜在的相互作用伙伴。我们在此表明，Chk2在体外和培养细胞中均能与CK2β特异性相互作用，且Chk2的激活会导致这种相互作用减少。此外，我们还表明，CK2β亚基的存在显著降低了Chk2在体外催化的p53磷酸化作用。这些发现支持了CK2β可作为蛋白激酶-底物相互作用中远程对接位点的一般调节剂这一观点。
