A GLUTAMINE-RICH HYDROPHOBIC PATCH IN TRANSCRIPTION FACTOR-SP1 CONTACTS THE DTAF(II)110 COMPONENT OF THE DROSOPHILA TFIID COMPLEX AND MEDIATES TRANSCRIPTIONAL ACTIVATION
A GLUTAMINE-RICH HYDROPHOBIC PATCH IN TRANSCRIPTION FACTOR-SP1 CONTACTS THE DTAF(II)110 COMPONENT OF THE DROSOPHILA TFIID COMPLEX AND MEDIATES TRANSCRIPTIONAL ACTIVATION
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DOI：
10.1073/pnas.91.1.192
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发表时间：
1994-01-04
影响因子：
11.1
通讯作者：
TJIAN, R
中科院分区：
文献类型：
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作者：
GILL, G;PASCAL, E;TJIAN, R
由启动子特异性因子Sp1激活转录需要与TFIID复合体中的TATA盒结合蛋白(TBP)紧密相关的辅助激活子。最近的研究表明，Sp1的两个富含谷氨酰胺的激活结构域A和B可以与该复合体的至少一个成分TBP相关因子dTAF(II)110相互作用。在这里，我们报道了Sp1的一个区域的定位，该区域含有交替的谷氨酰胺和疏水残基，这是与dTAF(II)110相互作用所必需的，并且对于介导转录激活是重要的。该区域内大量疏水残基的替代减少了与dTAF(II)110的相互作用和果蝇细胞中的转录激活。相反，该区域谷氨酰胺残基的突变没有影响。因此，Sp1-TAF相互作用的强度与Sp1作为转录激活因子的效力相关，表明这种激活因子-TAF相互作用是转录激活机制的重要组成部分。对与dTAF(II)110结合的三个激活域的序列比较表明，利用dTAF(II)110作为共激活剂的不同激活子可能具有共同的序列特征，我们已确定这些特征对Sp1-dTAF(II)110相互作用是重要的。
Activation of transcription by the promoter-specific factor Sp1 requires coactivators that are tightly associated with the TATA-box-binding protein (TBP) in the TFIID complex. Recent work has shown that the two glutamine-rich activation domains of Sp1, A and B, can interact with at least one component of this complex, the TBP-associated factor dTAF(II)110. Here we report the mapping of a region of Sp1 with alternating glutamine and hydrophobic residues which is required for the interaction with dTAF(II)110 and is important for mediating transcriptional activation. Substitution of bulky hydrophobic residues within this region decreased both interaction with dTAF(II)110 and transcriptional activation in Drosophila cells. In contrast, mutation of glutamine residues in this region had no effect. Thus, the strength of the Sp1-TAF interaction correlates with the potency of Sp1 as a transcriptional activator, indicating that this activator-TAF interaction is an important part of the mechanism of transcriptional activation. Sequence comparison of three activation domains shown to bind dTAF(II)110 suggests that different activators that utilize dTAF(II)110 as a coactivator may share common sequence features that we have determined to be important for the Sp1-dTAF(II)110 interaction.