Palvimo J, Mahonen A, Mäenpää P H
Department of Biochemistry, University of Kuopio, Finland.
Biochim Biophys Acta. 1987 Dec 10;931(3):376-83. doi: 10.1016/0167-4889(87)90229-1.
Chromosomal high-mobility-group (HMG) proteins have been examined as substrates for calcium/phospholipid-dependent protein kinase C. Protein kinase C from rat brain phosphorylated efficiently both HMG 14 and HMG 17 derived from calf thymus and the reactions were calcium/phospholipid-dependent. About 1 mol of 32P was incorporated per mol of HMG 14 and HMG 17. Phosphopeptide mapping suggested that the same major site was phosphorylated in both proteins at serine. The apparent Km values for HMG 14 and HMG 17 were about 5 microM. HMG 14, HMG 17 and the five histone H1 subtypes prepared from rat thymus, liver and spleen were phosphorylated by the kinase. HMG 14 and HMG 17 from transformed human lymphoblasts (Wi-L2) were also phosphorylated in a calcium/phospholipid-dependent manner. HMG 1 and HMG 2 from the tissues examined were found to be poor substrates for the kinase.
已将染色体高迁移率族（HMG）蛋白作为钙/磷脂依赖性蛋白激酶C的底物进行了研究。来自大鼠脑的蛋白激酶C能高效磷酸化源自小牛胸腺的HMG 14和HMG 17，且反应是钙/磷脂依赖性的。每摩尔HMG 14和HMG 17约掺入1摩尔32P。磷酸肽图谱分析表明，两种蛋白中相同的主要位点在丝氨酸处被磷酸化。HMG 14和HMG 17的表观Km值约为5 microM。该激酶可磷酸化从大鼠胸腺、肝脏和脾脏制备的HMG 14、HMG 17以及五种组蛋白H1亚型。来自转化的人淋巴母细胞（Wi-L2）的HMG 14和HMG 17也以钙/磷脂依赖性方式被磷酸化。在所检测的组织中发现，HMG 1和HMG 2是该激酶的不良底物。
