Van Mater D, Sowden M P, Cianci J, Sparks J D, Sparks C E, Ballatori N, Smith H C
Departments of Biochemistry and Biophysics, University of Rochester School of Medicine and Dentistry, Rochester, New York, 14642, USA.
Biochem Biophys Res Commun. 1998 Nov 18;252(2):334-9. doi: 10.1006/bbrc.1998.9647.
Apolipoprotein B (apoB) mRNA editing involves a site-specific cytidine to uridine transition catalyzed by the cytidine deaminase, APOBEC-1, in the context of and regulated by a multi-protein-containing editosome. ApoB mRNA editing in vivo is subject to tissue specific, developmental and metabolic regulation. We demonstrate for the first time that the amount of edited apoB mRNA in rat primary hepatocytes is markedly increased subsequent to transient treatment with ethanol in vitro. The apparent change in editing efficiency was dose-dependent (from 0.1%-2.4% initial ethanol dose) and occurred with rapid onset. The proportion of edited apoB mRNA was also markedly enhanced in a rat hepatoma cell line, McArdle RH7777 cells and in a stable McArdle cell line over-expressing APOBEC-1 by transient treatment with 2.5 % ethanol. In contrast, the apoB mRNA editing in a human hepatoma cell line, HepG2 cells and a stable HepG2 cell line over-expressing APOBEC-1 did not respond to ethanol treatment. The data support the possibility that editing activity is ethanol-responsive but suggest that this change is cell type-specific.
载脂蛋白B（apoB）mRNA编辑涉及由胞苷脱氨酶APOBEC-1催化的位点特异性胞苷向尿苷的转变，这一过程发生在含有多种蛋白质的编辑体环境中，并受其调控。体内的apoB mRNA编辑受组织特异性、发育和代谢的调节。我们首次证明，体外短暂用乙醇处理大鼠原代肝细胞后，编辑后的apoB mRNA量显著增加。编辑效率的明显变化呈剂量依赖性（初始乙醇剂量为0.1%-2.4%），且起效迅速。通过用2.5%乙醇短暂处理，在大鼠肝癌细胞系McArdle RH7777细胞以及过表达APOBEC-1的稳定McArdle细胞系中，编辑后的apoB mRNA比例也显著提高。相比之下，人肝癌细胞系HepG2细胞以及过表达APOBEC-1的稳定HepG2细胞系中的apoB mRNA编辑对乙醇处理无反应。这些数据支持编辑活性对乙醇有反应的可能性，但表明这种变化具有细胞类型特异性。
