PAX3对靶基因MITF转录活性调控的实验研究

Experimental Studies on Regulation of PAX3 on Transcriptional Activities of Target Gene MITF

张华;常尚揆;冯永;钱敏飞;李吉平;张淳;

1:上海交通大学医学院附属仁济医院耳鼻咽喉科

2:新疆医科大学第一附属医院耳鼻咽喉科

3:新疆昌吉州中医医院耳鼻咽喉科

4:中南大学湘雅医院耳鼻咽喉科

摘要
目的探讨配对盒基因(pair box 3,PAX3)突变对小眼球畸形相关转录因子(microphthalmia-associated transcription factor,MITF)基因转录活性的影响及其在I型Waardenburg综合征(Waardenburg syndrome,WS)发病中的作用。方法野生型PAX3及其致病突变H80D和H186fsX5表达质粒瞬时转染293T细胞,应用荧光素酶活性检测系统对MITF报告基因活性检测,观察野生/突变PAX3蛋白对其靶基因MITF转录活性的调控作用及二个突变蛋白对野生PAX3蛋白功能的影响;应用生物素标记的含序列attaat的DNA寡核苷酸链探针分别沉淀PAX3、H80D和H186fsX5蛋白,检测野生/突变PAX3蛋白与靶基因MITF启动子的结合力。结果尽管H80D蛋白仍残余部分功能可增加MITF启动子转录活性,但与野生PAX3蛋白相比,二者差异有显著统计学意义(P<0.01),而H186fsX5蛋白则完全失去调控MITF启动子转录活性作用(P<0.01);二者均未对野生PAX3蛋白功能产生显性负效应作用(P>0.05)。突变H80D蛋白与野生PAX3蛋白均可与MITF启动子特异DNA序列attaat结合,而突变H186fsX5蛋白则不能与之结合。结论 H80D和H186fsX5影响靶基因MITF转录活性,使其表达下调、黑色素合成减少,以单倍体剂量不足效应致I型WS。
关键词
Waardenburg综合征;配对盒基因;基因突变;小眼球畸形相关转录因子
基金项目(Foundation):
国家自然科学基金(81260160)资助
作者
张华;常尚揆;冯永;钱敏飞;李吉平;张淳;
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