THE HIGH-MOBILITY GROUP PROTEIN HMG I(Y) CAN STIMULATE OR INHIBIT DNA-BINDING OF DISTINCT TRANSCRIPTION FACTOR ATF-2 ISOFORMS
THE HIGH-MOBILITY GROUP PROTEIN HMG I(Y) CAN STIMULATE OR INHIBIT DNA-BINDING OF DISTINCT TRANSCRIPTION FACTOR ATF-2 ISOFORMS
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DOI：
10.1073/pnas.91.24.11318
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发表时间：
1994-11-22
影响因子：
11.1
通讯作者：
MANIATIS, T
中科院分区：
文献类型：
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作者：
DU, W;MANIATIS, T
高迁移率族蛋白HMG I（Y）刺激转录激活因子2（ATF-2（195））的特异性同种型与干扰素β（IFN-β）基因启动子的结合。HMG I（Y）特异性地与ATF-2的碱性亮氨酸拉链区相互作用（195），并且HMG I（Y）结合紧邻IFN-β启动子的ATF-2结合位点侧翼的两个位点。在这里，我们表明，HMG I（Y）可以刺激ATF-2（195）的结合，至少部分，通过促进ATF-2二聚化。此外，我们报告了ATF-2（ATF-2（192））的天然亚型的特征，该亚型特异性结合IFN-β启动子，但不能与HMG I（Y）相互作用。值得注意的是，HMG I（Y）抑制ATF-2（192）与IFN-β启动子的结合。因此，HMG I（Y）与ATF-2特异性相互作用的能力与其刺激ATF-2与IFN-β启动子结合的能力相关。ATF-2（195）和ATF-2（192）的碱性亮氨酸拉链结构域的氨基酸序列的比较表明，HMG I（Y）与ATF-2（195）的碱性亮氨酸拉链结构域的氨基末端附近的一小段碱性氨基酸相互作用。
The high mobility group protein HMG I(Y) stimulates the binding of a specific isoform of the activating transcription factor 2 (ATF-2(195)) to the interferon beta (IFN-beta) gene promoter. HMG I(Y) specifically interacts with the basic-leucine zipper region of ATF-2(195), and HMG I(Y) binds to two sites immediately flanking the ATF-2 binding site of the IFN-beta promoter. Here, we show that HMG I(Y) can stimulate the binding of ATF-2(195), at least in part, by promoting ATF-2 dimerization. In addition, we report the characterization of a naturally occurring isoform of ATF-2 (ATF-2(192)) that binds specifically to the IFN-beta promoter but is unable to interact with HMG I(Y). Remarkably, HMG I(Y) inhibits the binding of ATF-2(192) to the IFN-beta promoter. Thus, the ability of HMG I(Y) to specifically interact with ATF-2 correlates with its ability to stimulate ATF-2 binding to the IFN-beta promoter. Comparisons of the amino acid sequences of the basic-leucine zipper domains of ATF-2(195) and ATF-2(192) suggest that HMG I(Y) interacts with a short stretch of basic amino acids near the amino terminus of the basic-leucine zipper domain of ATF-2(195).