Importance of low affinity Elf-1 sites in the regulation of lymphoid-specific inducible gene expression.
Importance of low affinity Elf-1 sites in the regulation of lymphoid-specific inducible gene expression.
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DOI：
10.1084/jem.183.3.743
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发表时间：
1996-03-01
影响因子：
15.3
通讯作者：
Leonard, WJ
中科院分区：
文献类型：
--
作者：
John, S;Marais, R;Child, R;Light, Y;Leonard, WJ
Elf-1是一种Ets家族转录因子，调节许多诱导型淋巴特异性基因，包括编码白细胞介素3（IL-3）、粒细胞/巨噬细胞集落刺激因子（GM-CSF）和IL-2受体（IL-2 R）α链的基因。跨越IL-2 R α Elf-1位点的最小寡核苷酸（-97/-84）与Elf-1的结合较差，但当该寡核苷酸被多聚化或添加侧翼序列时，结合活性显著增加。这一结果与辅助蛋白对于有效的Elf- 1结合的要求一致，如已经对GM-CSF和IL-3启动子所证明的。结合位点选择分析显示最佳Elf-1共有基序为A（A/t）（C/a）CCGGAAGT（A/S），其与相关果蝇E74蛋白的共有基序相似。当克隆到异源启动子的上游时，该最小的高亲和力位点可以结合Elf-1，并且作为比-97/-84 IL-2 R α寡核苷酸更强的转录元件发挥作用。相反，在IL-2 R α启动子的情况下，天然存在的低亲和力Elf-1位点向最佳位点的转化降低了Jurkat细胞中报告构建体的诱导型激活。这一发现可以通过观察到另一种Ets家族蛋白，ER GB/Fli-1，可以有效地结合到最佳位点来解释，并且在这种情况下，干扰Elf-1结合。因此，高亲和力Elf-1位点可能缺乏足够的结合特异性，而天然存在的低亲和力位点可能有利于Elf-1在辅助蛋白中的结合。这些发现为任何已知的Elf-1调控基因中缺乏最佳位点提供了解释。
Elf-1 is an Ets family transcription factor that regulates a number of inducible lymphoid-specific genes, including those encoding interleukin 3 (IL-3), granulocyte/macrophage colony-stimulating factor (GM-CSF), and the IL-2 receptor (IL-2R) alpha chain. A minimal oligonucleotide spanning the IL-2R alpha Elf-1 site (-97/-84) bound Elf-1 poorly, but binding activity markedly increased when this oligonucleotide was multimerized or flanking sequences were added. This result is consistent with the requirement of accessory proteins for efficient Elf- 1 binding, as has been demonstrated for the GM-CSF and IL-3 promoters. A binding site selection analysis revealed the optimal Elf-1 consensus motif to be A(A/t)(C/a)CCGGAAGT(A/S), which is similar to the consensus motif for the related Drosophila E74 protein. This minimal high affinity site could bind Elf-1 and functioned as a stronger transcription element than the -97/-84 IL-2R alpha oligonucleotide when cloned upstream of a heterologous promoter. In contrast, in the context of the IL-2R alpha promoter, conversion of the naturally occurring low affinity Elf-1 site to an optimal site decreased inducible activation of a reporter construct in Jurkat cells. This finding may be explained by the observation that another Ets family protein, ER GB/Fli-1, can efficiently bind only to the optimal site, and in this context, interferes with Elf-1 binding. Therefore, high affinity Elf-1 sites may lack sufficient binding specificity, whereas naturally occurring low affinity sites presumably favor the association of Elf-1 in the context of accessory proteins. These findings offer an explanation for the lack of optimal sites in any of the known Elf-1-regulated genes.
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影响因子：
14.9
作者：
POLLOCK, R;TREISMAN, R
通讯作者：
TREISMAN, R
影响因子：
56.9
作者：
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通讯作者：
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影响因子：
14.9
作者：
WOODS, DB;GHYSDAEL, J;OWEN, MJ
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OWEN, MJ
DOI：
10.1073/pnas.89.4.1291
发表时间：
1992-02-15
影响因子：
11.1
作者：
DUDEK, H;TANTRAVAHI, RV;REDDY, EP
通讯作者：
REDDY, EP
影响因子：
15.3
作者：
GOTTSCHALK, LR;GIANNOLA, DM;EMERSON, SG
通讯作者：
EMERSON, SG