Park Pil-Hoon, Miller Rebecca, Shukla Shivendra D
Department of Medical Pharmacology and Physiology, School of Medicine, University of Missouri at Columbia, One Hospital Drive, Rm. M517B Med. Sci. Bldg., Columbia, MO 65212, USA.
Biochem Biophys Res Commun. 2003 Jun 27;306(2):501-4. doi: 10.1016/s0006-291x(03)01040-4.
Histone acetylation plays an important role in transcriptional activation. We have investigated the effect of ethanol on nuclear histone H3 acetylation in rat hepatocytes. Hepatocytes were incubated with ethanol (5-200 mM) for 24h and then acetylation states of nuclear histone H3 at specific lysine residues (Lys(9) and Lys(14)) were measured by immunoblot analysis using site-specific antibodies. Ethanol increased acetylation of histone H3 at Lys(9) in a dose-dependent manner; 3-fold at 5mM and maximum of 8-fold at 100mM. Sensitivity to low dose of ethanol was remarkable. This ethanol-induced acetylation was also time-dependent, showing a maximal response at 24h. Ethanol did not alter the level of histone H3 expression. Trichostatin A, a histone deacetylase inhibitor, was used as a positive control and it also increased acetylation. However, acetylation at Lys(14) was not affected by ethanol. Treatment of cells with ethanol metabolizing enzyme inhibitors (4-methylpyrazole and cyanamide) decreased ethanol-induced histone H3 acetylation at Lys(9). This is the first report of ethanol-induced selective, post-translational acetylation of histone H3 at Lys(9). This is not due to increased histone expression or a direct physical effect of ethanol but is dependent on ethanol metabolism.
组蛋白乙酰化在转录激活中起重要作用。我们研究了乙醇对大鼠肝细胞中核组蛋白H3乙酰化的影响。将肝细胞与乙醇（5 - 200 mM）孵育24小时，然后使用位点特异性抗体通过免疫印迹分析测量核组蛋白H3在特定赖氨酸残基（Lys(9)和Lys(14)）处的乙酰化状态。乙醇以剂量依赖的方式增加组蛋白H3在Lys(9)处的乙酰化；在5 mM时增加3倍，在100 mM时最大增加8倍。对低剂量乙醇的敏感性显著。这种乙醇诱导的乙酰化也是时间依赖性的，在24小时时显示出最大反应。乙醇不改变组蛋白H3的表达水平。曲古抑菌素A，一种组蛋白脱乙酰酶抑制剂，用作阳性对照，它也增加乙酰化。然而，Lys(14)处的乙酰化不受乙醇影响。用乙醇代谢酶抑制剂（4 - 甲基吡唑和氰胺）处理细胞可降低乙醇诱导的组蛋白H3在Lys(9)处的乙酰化。这是关于乙醇诱导组蛋白H3在Lys(9)处选择性翻译后乙酰化的首次报道。这不是由于组蛋白表达增加或乙醇的直接物理作用，而是依赖于乙醇代谢。
