鼠生长激素基因中的c-erb-A结合位介导甲状腺激素的转激活
C K Glass1, R Franco, C Weinberger
1Centre for Molecular Genetics, University of California, San Diego, La Jolla 92093.
Nature
|October 22, 1987
概括
甲状腺激素 (T3) 通过与DNA结合的核受体刺激生长激素基因转录. 研究人员在老鼠生长激素基因上确定了一个特定的T3受体结合部位,证实了c-erb-A基因产物.
科学领域:
- 分子内分泌学分子内分泌学
- 基因法规 基因法规
- 核受体的功能 核受体的功能
背景情况:
- 甲状腺激素 (3,5,3-triiodothyronine,T3) 调节基因转录,包括 pituitary 细胞中的生长激素 (GH) 基因表达.
- T3的作用是由核T3受体与DNA调节元件结合的介导,但由于丰度较低,其净化和特定的结合位点难以确定.
- 最近的研究确定了c-erb-A基因产物作为具有受体特征的高亲和度甲状腺激素结合剂.
研究的目的:
- 开发一种检测特定T3受体-DNA相互作用的方法.
- 识别大鼠生长激素 (GH) 基因促进体中T3受体识别的DNA序列.
- 研究c-erb-A基因产物在调节T3调节的GH基因转录中的作用.
主要方法:
- 开发一种阿维丁-生物复合物的DNA结合测定,以检测核T3受体结合.
- 在大鼠垂体GC2细胞中进行寡核酸转染试验,以评估T3调节.
- 在体外结合试验中使用人类胎盘c-erb-A基因的体外翻译产物.
主要成果:
- 阿维丁-生物素测定检测到特定的,高亲和力结合大鼠垂体T3受体的序列5'CAGGGACGTGACCGCA3'位于大鼠GH基因开始地点的164bp上游.
- 含有这种序列的寡核酸将T3调节赋予了转染细胞中的异质促进体 (简单疹病毒胆氨酸激酶).
- 鉴定的DNA序列在体外特别结合了人类胎盘c-erb-A基因产物.
结论:
- 人类c-erb-A基因产物可能是T3对GH基因转录效应的调解者.
- 已识别的DNA序列代表了大鼠GH基因中的T3反应元素.
- 下垂体细胞中的额外的核因子可能会调节T3受体与GH基因T3反应元素的结合.
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