Watanabe F, Shirakawa H, Yoshida M, Tsukada K, Teraoka H
Medical Research Institute, Tokyo Medical and Dental University, Japan.
Biochem Biophys Res Commun. 1994 Jul 29;202(2):736-42. doi: 10.1006/bbrc.1994.1992.
After incubation of high mobility group (HMG) proteins 1 and 2 with DNA-dependent protein kinase (DNA-PK) and [gamma-32P]ATP in the presence of double-stranded DNA, not only phosphorylation of HMG proteins but also enhancement of autophosphorylation of the catalytic polypeptide of 350 kDa in DNA-PK was observed. DNA-PK activity determined with a synthetic peptide and alpha-casein as substrates was stimulated several-fold by HMG1, HMG2, and the DNA-binding domains. The stimulation was decreased at higher concentrations of HMG proteins, and DNA-PK activity was inhibited by histone H1. Electrophoretic mobility shift analysis suggests that HMG proteins facilitate the binding of DNA-PK to DNA.
在双链DNA存在的情况下，将高迁移率族（HMG）蛋白1和2与DNA依赖性蛋白激酶（DNA-PK）及[γ-32P]ATP一起孵育后，不仅观察到HMG蛋白的磷酸化，还观察到DNA-PK中350 kDa催化多肽的自身磷酸化增强。以合成肽和α-酪蛋白为底物测定的DNA-PK活性受到HMG1、HMG2及DNA结合结构域的数倍刺激。在较高浓度的HMG蛋白时刺激作用减弱，并且DNA-PK活性受到组蛋白H1的抑制。电泳迁移率变动分析表明，HMG蛋白促进DNA-PK与DNA的结合。
