Chiesa G, Johnson D F, Yao Z, Innerarity T L, Mahley R W, Young S G, Hammer R H, Hobbs H H
Department of Molecular Genetics, Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas 75235.
J Biol Chem. 1993 Nov 15;268(32):23747-50.
Apolipoprotein B (apoB) is a large glycoprotein that circulates in plasma as a major constituent of numerous lipoproteins. ApoB exists in two forms: apoB48 and apoB100. ApoB48 is identical in sequence to the N-terminal region of apoB100 and is generated by sequence-specific mRNA editing of the apoB100 transcript. Here, we describe the development of a line of mice expressing a human apoB transgene driven by promoter/enhancer sequences from the transthyretin gene. In these mice, immunodetectable human apoB100 is synthesized by the liver, kidney, and brain. Human apoB100 is found in low concentration (approximately 0.1 mg/dl) in the plasma of the transgenic mice and circulates in the low density lipoprotein fraction. The hepatic human apoB100 transcripts undergo mRNA editing at only slightly lower efficiency than the endogenous mouse apoB100 message. Therefore, there is no absolute species specificity to the apoB100 mRNA editing process.
载脂蛋白B（apoB）是一种大型糖蛋白，作为众多脂蛋白的主要成分在血浆中循环。ApoB有两种形式：apoB48和apoB100。ApoB48在序列上与apoB100的N端区域相同，由apoB100转录本的序列特异性mRNA编辑产生。在此，我们描述了一种小鼠品系的培育过程，该品系小鼠表达由甲状腺素运载蛋白基因的启动子/增强子序列驱动的人apoB转基因。在这些小鼠中，肝脏、肾脏和大脑可合成免疫可检测的人apoB100。在转基因小鼠的血浆中发现人apoB100的浓度较低（约0.1mg/dl），并在低密度脂蛋白组分中循环。肝脏中的人apoB100转录本进行mRNA编辑的效率仅略低于内源性小鼠apoB100信息。因此，apoB100 mRNA编辑过程不存在绝对的物种特异性。
