Role of important hydrophobic amino acids in the interaction between the glucocorticoid receptor τ1-core activation domain and target factors
Role of important hydrophobic amino acids in the interaction between the glucocorticoid receptor τ1-core activation domain and target factors
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DOI：
10.1021/bi973029x
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发表时间：
1998-06-30
期刊：
影响因子：
2.9
通讯作者：
Wright, APH
中科院分区：
文献类型：
--
作者：
Almlöf, T;Wallberg, AE;Wright, APH
在这项工作中，我们确定了影响人类糖皮质激素受体 (GR) tau 1 核心激活域内疏水残基的功能改变突变体如何影响其与转录机制的不同靶蛋白的物理相互作用。对假定靶蛋白的筛选表明，tau 1 核心可以与 CREB 结合蛋白 (CBP) 的 C 端部分相互作用。此外，之前确定的 tau 1 核心与 TATA 结合蛋白 (TBP) 和 Ada2 衔接蛋白的相互作用分别位于这些蛋白的 C 端和 N 端区域。 tau 1 核心内一组降低或增加激活电位的突变被用来探测 tau 1 核心结构域与 TBP、Ada2 和 CBP 的相互作用。我们发现，每种相互作用的突变引起的影响模式都是相似的，并且对结合的影响通常反映了对基因激活潜力的影响。因此，突变的主要效应似乎影响了所有三种相互作用所共有的 tau 1-核心特性，而不是每个目标因子相互作用单独需要的不同特性。这种特性可能是结构域采用折叠构象的能力，而折叠构象通常是与目标因子相互作用所必需的。我们还表明，TBP、Ada2 和 CBP 可以与 tau 1 核心和 GR 配体结合结构域相互作用，为 tau 1 核心和其他受体激活结构域之间的协同相互作用提供可能的机制。然而，在我们的条件下，与 GR C 末端相互作用的其他靶蛋白（例如 RIP140 和 SRC-1）并未表现出与 tau 1 核心的显着相互作用。
In this work, we determined how altered-function mutants affecting hydrophobic residues within the tau 1-core activation domain of the human glucocorticoid receptor (GR) influence its physical interaction with different target proteins of the transcriptional machinery. Screening of putative target proteins showed that the tau 1-core can interact with the C-terminal part of the CREB-binding protein (CBP). In addition, the previously identified interactions of the tau 1-core with the TATA-binding protein (TBP) and the Ada2 adaptor protein were localized to the C- and N-terminal regions of these proteins, respectively. A panel of mutations within the tau 1-core that either decrease or increase activation potential was used to probe the interaction of the tau 1-core domain with TBP, Ada2, and CBP. We found that the pattern of effects caused by the mutations was similar for each of the interactions and that the effects on binding generally reflected effects on gene activation potential. Thus, the predominant effect of the mutations appears to influence a property of the tau 1-core that is common to all three interactions, rather than properties that are differentially required by each of the target factor interactions, individually, Such a property could be the ability of the domain to adopt a folded conformation that is generally necessary for interaction with target factors. We have also shown that TBP, Ada2, and CBP can interact with both the tau 1-core and the GR ligand-binding domain, offering a possible mechanism for synergistic interaction between the tau 1-core and other receptor activation domains. However, other target proteins (e.g., RIP140, and SRC-1), which interact with the GR C terminus, did not show significant interactions with the tau 1-core under our conditions.