Akinshola B E, Potter J J, Mezey E
Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205.
Alcohol. 1993 Mar-Apr;10(2):163-7. doi: 10.1016/0741-8329(93)90098-9.
Ethanol was shown previously to increase ADP-ribosylation of hepatocyte proteins. The purpose of this study was to determine the effect of ethanol on ADP-ribosylation of histones in hepatocyte nuclei. Freshly isolated hepatocytes were exposed to 100 mM ethanol for 2 h and ADP-ribosylated histones were separated from nonribosylated histones by phenylboronate agarose chromatography. Both histone factions were then separated into the individual histones by 12% acetic-urea-triton polyacrylamide gel electrophoresis. Ethanol did not change the amounts of outer histone H1 or amounts of core histones (H2A, H2B, H3.1, and H4) but increased the histone variants H3.2 and H3.3. The principal effect of ethanol was to increase the ADP-ribosylation of all the above histones. Exposure of hepatocytes in culture to 100 mM ethanol for 3 days did not increase the synthesis of histones as determined by the incorporation of 14C-L-lysine, but increased the ADP-ribosylation of histones, principally histone H2A, determined from the incorporation of 2, 8, 3H adenosine. These results show that ethanol increases the ADP-ribosylation of histones. This is a potential mechanism for effects of ethanol on the regulation of gene expression and cell differentiation.
先前的研究表明，乙醇可增加肝细胞蛋白质的ADP-核糖基化。本研究的目的是确定乙醇对肝细胞核中组蛋白ADP-核糖基化的影响。将新鲜分离的肝细胞暴露于100 mM乙醇中2小时，然后通过苯基硼酸琼脂糖色谱法将ADP-核糖基化组蛋白与未核糖基化组蛋白分离。接着，通过12%乙酸-尿素- Triton聚丙烯酰胺凝胶电泳将两个组蛋白组分分离为单个组蛋白。乙醇并未改变组蛋白H1的含量或核心组蛋白（H2A、H2B、H3.1和H4）的含量，但增加了组蛋白变体H3.2和H3.3的含量。乙醇的主要作用是增加上述所有组蛋白的ADP-核糖基化。通过14C-L-赖氨酸掺入量测定，将培养的肝细胞暴露于100 mM乙醇中3天，并未增加组蛋白的合成，但通过2, 8, 3H腺苷掺入量测定，增加了组蛋白的ADP-核糖基化，主要是组蛋白H2A。这些结果表明，乙醇可增加组蛋白的ADP-核糖基化。这是乙醇影响基因表达调控和细胞分化的一种潜在机制。
