Asami K, Kobayashi H, Fujiwara A, Yasumasu I
National Institute of Radiological Sciences, Tokyo, Japan.
Radiat Res. 1989 Sep;119(3):500-10.
X rays (4.8 Gy) inhibit both DNA synthesis and phosphorylation of histone H1 in the regenerating liver of the rat. To determine the cause of the inhibition of histone H1 phosphorylation, changes in the nuclear protein kinase activities during the prereplicative phase of regeneration were measured. The cAMP-dependent protein kinase activity was low during regeneration, and the changes in the activity were not statistically significant. The cAMP-independent protein kinase activity increased at 15 h, decreased at 18 h, and increased again at 24 h after partial hepatectomy. X irradiation prior to partial hepatectomy did not inhibit the increase at 15 h, but it did inhibit the increase at 24 h. The activity was not inhibited by isoquinolinesulfonamide inhibitors such as H-7, and it was activated by a commercial preparation of an inhibitor protein of the cAMP-dependent kinase. It was also inhibited by quercetin. The possibility that the radiation-sensitive nuclear protein kinase is a nuclear cAMP-independent protein kinase specific for histone H1 is considered.
X射线（4.8戈瑞）抑制大鼠再生肝脏中DNA的合成以及组蛋白H1的磷酸化。为了确定组蛋白H1磷酸化受抑制的原因，我们检测了再生前期核蛋白激酶活性的变化。在再生过程中，依赖cAMP的蛋白激酶活性较低，且活性变化无统计学意义。非依赖cAMP的蛋白激酶活性在部分肝切除术后15小时升高，18小时降低，24小时再次升高。部分肝切除术前进行X射线照射并不抑制15小时时的升高，但会抑制24小时时的升高。该活性不受异喹啉磺酰胺抑制剂（如H-7）的抑制，且被一种依赖cAMP激酶的抑制蛋白的商业制剂激活。它也被槲皮素抑制。我们考虑了辐射敏感的核蛋白激酶可能是一种对组蛋白H1具有特异性的核非依赖cAMP蛋白激酶的可能性。
