Niedergang C P, de Murcia G, Ittel M E, Pouyet J, Mandel P
Eur J Biochem. 1985 Jan 2;146(1):185-91. doi: 10.1111/j.1432-1033.1985.tb08637.x.
Isolated rat pancreatic polynucleosomes were poly(ADP-ribosylated) with purified calf thymus poly(ADP-ribose) polymerase. A time course study was performed using an NAD concentration of 200 microM and changes in nucleosomal structure were investigated by means of electron microscopy visualization and sedimentation velocity determinations. In parallel, analyses of histone H1 poly(ADP-ribosylation) and determinations of DNA polymerase alpha activity on ADP-ribosylated polynucleosomes were done at different time intervals. A direct kinetic correlation between ADP-ribose incorporation, polynucleosome relaxation amd histone H1 hyper-ADP-ribosylation was established. In addition, DNA polymerase alpha activity was highly stimulated on ADP-ribosylated polynucleosomes as compared to control ones, suggesting increased accessibility of DNA to enzymatic action. Because of the strong evidence implicating histone H1 in the maintenance of higher-ordered chromatin structures, the present study may provide a basis for the interpretation of the involvement of the histone H1 ADP-ribosylation reaction in DNA rearrangements during DNA repair, replication or gene expression.
将纯化的小牛胸腺多聚（ADP - 核糖）聚合酶与分离的大鼠胰腺多核小体进行多聚（ADP - 核糖基化）反应。使用200微摩尔的NAD浓度进行了时间进程研究，并通过电子显微镜观察和沉降速度测定来研究核小体结构的变化。同时，在不同时间间隔对组蛋白H1的多聚（ADP - 核糖基化）进行分析，并测定ADP - 核糖基化多核小体上的DNA聚合酶α活性。建立了ADP - 核糖掺入、多核小体松弛和组蛋白H1超ADP - 核糖基化之间的直接动力学相关性。此外，与对照多核小体相比，ADP - 核糖基化多核小体上的DNA聚合酶α活性受到高度刺激，这表明DNA对酶促作用的可及性增加。由于有充分证据表明组蛋白H1参与维持高阶染色质结构，本研究可能为解释组蛋白H1 ADP - 核糖基化反应在DNA修复、复制或基因表达过程中的DNA重排中的作用提供基础。
