THE LOOP REGION OF THE HELIX-LOOP-HELIX PROTEIN ID1 IS CRITICAL FOR ITS DOMINANT-NEGATIVE ACTIVITY
THE LOOP REGION OF THE HELIX-LOOP-HELIX PROTEIN ID1 IS CRITICAL FOR ITS DOMINANT-NEGATIVE ACTIVITY
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DOI：
10.1128/mcb.13.12.7874
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发表时间：
1993-12-01
影响因子：
5.3
通讯作者：
BENEZRA, R
中科院分区：
文献类型：
--
作者：
PESCE, S;BENEZRA, R
Id 1是一种缺乏DNA结合结构域的螺旋-环-螺旋（HLH）蛋白，已被证明通过直接的蛋白质-蛋白质相互作用在体外和体内负调节HLH家族的其他成员。在这项研究中，我们报告的定点突变实验的结果，目的是确定该地区的Id 1是重要的，其活动。我们发现Id 1的HLH结构域是其活性所必需的，并且几乎足够。此外，我们表明，两个氨基酸残基的Id 1环的氨基末端是其活动的关键，也许通过指定正确的二聚化合作伙伴。在这方面，用Id 1的相应氨基酸替换碱性HLH蛋白E12和E47的环的前四个氨基酸赋予Id 1二聚化特异性。这些研究指出环区作为HLH蛋白Id亚家族的重要结构和功能元件。
Id1, a helix-loop-helix (HLH) protein which lacks a DNA binding domain, has been shown to negatively regulate other members of the HLH family by direct protein-protein interactions, both in vitro and in vivo. In this study, we report the results of site-directed mutagenesis experiments aimed at defining the regions of Id1 which are important for its activity. We have found that the HLH domain of Id1 is necessary and nearly sufficient for its activity. In addition, we show that two amino acid residues at the amino terminus of the Id1 loop are critical for its activity, perhaps by specifying the correct dimerization partners. In this regard, replacing the first four amino acids of the loops of the basic HLH proteins E12 and E47 with the corresponding amino acids of Id1 confers Id1 dimerization specificity. These studies point to the loop region as an important structural and functional element of the Id subfamily of HLH proteins.