An androgen receptor NH2-terminal conserved motif interacts with the COOH terminus of the Hsp70-interacting protein (CHIP)
An androgen receptor NH2-terminal conserved motif interacts with the COOH terminus of the Hsp70-interacting protein (CHIP)
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DOI：
10.1074/jbc.m403117200
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发表时间：
2004-07-16
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;Bai, SX;Wilson, EM
类固醇受体的NH2末端序列在不同的受体之间以及不同物种的同一受体中有很大的差异。在这项研究中，通过初步的序列同源性比较，确定了人雄激素受体(AR)的一个14个氨基酸的NH2末端基序，该基序在所有已报道的物种中都是共同的，包括低等脊椎动物。除了高等物种糖皮质激素受体的部分序列外，进化上保守的基序是AR所独有的。AR和糖皮质激素受体中保守基序的存在和其他类固醇受体中的缺失提示了趋同进化。从酵母双杂交筛选中推测了AR NH2末端保守基序的功能，该筛选鉴定了Hsp70相互作用蛋白(CHIP)的COOH末端为结合伙伴。我们发现，CHIP通过促进AR的降解，对AR转录活性起负调控作用。为了支持这一点，先前在转基因小鼠前列腺癌模型中发现的AR NH2末端保守基序的两个突变减少了CHIP和AR之间的相互作用。我们的结果表明，AR NH2末端结构域包含一个进化保守的基序，其功能是限制AR的转录活性。此外，我们证明了以短保守肽为诱饵的比较序列比对和酵母双杂交筛选相结合的方法为探索类固醇受体NH2末端结构域和其他内在非结构化转录调节蛋白的结构与功能关系提供了一种有效的策略。
The NH2-terminal sequence of steroid receptors is highly variable between different receptors and in the same receptor from different species. In this study, a primary sequence homology comparison identified a 14-amino acid NH2-terminal motif of the human androgen receptor (AR) that is common to AR from all species reported, including the lower vertebrates. The evolutionarily conserved motif is unique to AR, with the exception of a partial sequence in the glucocorticoid receptor of higher species. The presence of the conserved motif in AR and the glucocorticoid receptor and its absence in other steroid receptors suggests convergent evolution. The function of the AR NH2-terminal conserved motif was suggested from a yeast two-hybrid screen that identified the COOH terminus of the Hsp70-interacting protein (CHIP) as a binding partner. We found that CHIP functions as a negative regulator of AR transcriptional activity by promoting AR degradation. In support of this, two mutations in the AR NH2-terminal conserved motif previously identified in the transgenic adenocarcinoma of mouse prostate model reduced the interaction between CHIP and AR. Our results suggest that the AR NH2-terminal domain contains an evolutionarily conserved motif that functions to limit AR transcriptional activity. Moreover, we demonstrate that the combination of comparative sequence alignment and yeast two-hybrid screening using short conserved peptides as bait provides an effective strategy to probe the structure-function relationships of steroid receptor NH2-terminal domains and other intrinsically unstructured transcriptional regulatory proteins.