The FXXLF motif mediates androgen receptor-specific interactions with coregulators
The FXXLF motif mediates androgen receptor-specific interactions with coregulators
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DOI：
10.1074/jbc.m111975200
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发表时间：
2002-03-22
影响因子：
4.8
通讯作者：
Wilson, EM
中科院分区：
文献类型：
--
作者：
He, B;Minges, JT;Wilson, EM
配体结合结构域的雄激素受体 (AR) 激活功能 2 区域与 p160 共激活子的 LXXLL 基序微弱结合，而是与 AR NH2 末端的 FXXLF 基序进行雄激素依赖性结构域间相互作用。在这里，我们表明 FXXLF 基序存在于先前报道的 AR 共激活剂 ARA70/RFG、AJRA55/Hic-5 和 ARA54 中，这解释了它们在酵母双杂交筛选中的选择。哺乳动物双杂交测定、配体解离率研究和谷胱甘肽 S-转移酶吸附测定表明这些 FXXLF 基序与 AR 配体结合域的雄激素依赖性选择性相互作用。激活函数 2 内残基的诱变表明不同但重叠的结合位点，其中特异性取决于 FXXLF 基序内部和侧翼的序列。 FXXLF 基序的诱变消除了与配体结合结构域的相互作用，但仅适度降低了转录测定中 AR 的共激活。研究表明，FXXLF 结合基序对 AR 具有特异性，并介导 AR 内以及与辅助调节蛋白的相互作用。
The androgen receptor (AR) activation function 2 region of the ligand binding domain binds the LXXLL motifs of p160 coactivators weakly, engaging instead in an androgen-dependent, interdomain interaction with an FXXLF motif in the AR NH2 terminus. Here we show that FXXLF motifs are present in previously reported AR coactivators ARA70/RFG, AJRA55/Hic-5, and ARA54, which account for their selection in yeast two-hybrid screens. Mammalian two-hybrid assays, ligand dissociation rate studies, and glutathione S-transferase adsorption assays indicate androgen-dependent selective interactions of these FXXLF motifs with the AR ligand binding domain. Mutagenesis of residues within activation function 2 indicates distinct but overlapping binding sites where specificity depends on sequences within and flanking the FXXLF motif. Mutagenesis of the FXXLF motifs eliminated interaction with the ligand binding domain but only modestly reduced AR coactivation in transcription assays. The studies indicate that the FXXLF binding motif is specific for the AR and mediates interactions both within the AR and with coregulatory proteins.