THE PROTEIN ID - A NEGATIVE REGULATOR OF HELIX-LOOP-HELIX DNA-BINDING PROTEINS
THE PROTEIN ID - A NEGATIVE REGULATOR OF HELIX-LOOP-HELIX DNA-BINDING PROTEINS
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DOI：
10.1016/0092-8674(90)90214-y
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发表时间：
1990-04-06
期刊：
影响因子：
64.5
通讯作者：
WEINTRAUB, H
中科院分区：
文献类型：
--
作者：
BENEZRA, R;DAVIS, RL;WEINTRAUB, H
我们已经分离到一个编码新的螺旋-环-螺旋(HLH)蛋白ID的cDNA克隆。ID缺失HLH域附近的碱性区域，该区域是另一种HL蛋白MyoD中特定DNA结合所必需的。ID的体外翻译产物可以与至少三种HLH蛋白(MyoD、E12和E47)特异性结合，并减弱它们以同二聚体或异二聚体的形式与DNA结合的能力。ID在所有被测试的细胞系中都有不同程度的表达。在三个可被诱导为终末分化的细胞系中，ID RNA水平在诱导后下降。转基因实验表明，过表达ID抑制了MyoD对肌酸激酶增强子的反式激活。基于这些发现，我们认为，缺乏碱性区域的HLH蛋白可能通过形成无功能的异二聚体复合体来负调控其他HLH蛋白。
We have isolated a cDNA clone encoding a novel helix-loop-helix (HLH) protein, Id. Id is missing the basic region adjacent to the HLH domain that is essential for specific DNA binding in another HL protein, MyoD. An in vitro translation product of Id can associate specifically with at least three HLH proteins (MyoD, E12, and E47) and attenuate their ability to bind DNA as homodimeric or heterodimeric complexes. Id is expressed at varying levels in all cell lines tested. In three cell lines that can be induced to undergo terminal differentiation, Id RNA levels decrease upon induction. Transfection experiments indicate that overexpression of Id inhibits the trans-activation of the muscle creatine kinase enhancer by MyoD. Based on these findings, we propose that HLH proteins lacking a basic region may negatively regulate other HLH proteins through the formation of nonfunctional heterodimeric complexes.