Characterization of two nuclear androgen receptors in Atlantic croaker: comparison of their biochemical properties and binding specificities.
Characterization of two nuclear androgen receptors in Atlantic croaker: comparison of their biochemical properties and binding specificities.
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DOI：
10.1210/endo.140.4.6631
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发表时间：
1999-04
期刊：
影响因子：
4.8
通讯作者：
T. Sperry;Peter Thomas
中科院分区：
文献类型：
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作者：
T. Sperry;Peter Thomas
在波状小梭子鱼（Micropogonias atus）脑和卵巢中鉴定出两种具有不同特征的雄激素受体。在大脑中发现了一种核AR AR1，它对睾酮具有高亲和力结合位点（T; Kd, 1.1 +/- 0.15 nM；结合能力，1.4 +/- 0.14 pmol/g组织；n = 16）。在卵巢中发现了第二个核AR AR2，它对5 α -二氢睾酮具有高亲和力结合位点（DHT, Kd, 0.62 +/- 0.1 nM；结合力，0.38 +/- 0.06 pmol/g组织，n = 14）。AR2具有与其他脊椎动物ARs相似的物理化学性质。AR2对广泛的天然和合成雄激素具有高亲和力结合，包括17α -甲基-5 α -二氢睾酮，其相对结合亲和力DHT = 100% > T >米bolerone > 11-酮睾酮= 16%，快速结合（t1/2, 44 min）和缓慢解离（t1/2, 45 h）速率，并与纯化DNA特异性结合。胞质AR2与热休克蛋白的相互作用方式与其他类固醇受体类似，钼酸钠稳定受体，在5-20%蔗糖梯度下具有7.4-7.8S的沉降系数。相比之下，AR1仅对少数雄激素具有高度特异性，其相对结合亲和力为T = 100%, >> DHT >> 11-酮睾酮>米bolerone > 17α -甲基-5 α -二氢睾酮= 0，具有快速的结合（t1/2, 15分钟）和解离（t1/2, 2.6 +/- 0.7小时）速率，并且在热激活后与纯化的DNA具有特异性结合。胞质结合组分在5-20%蔗糖梯度下在5.6-5.7S沉积，不受钼酸钠的影响，这表明AR1不以通常的方式与热休克蛋白相互作用。这是首次报道在单一脊椎动物物种中存在两种不同的核ar，显示出明显不同的类固醇结合特异性。
Two distinct androgen receptors (ARs) with different characteristics were identified in the brain and ovary of Atlantic croaker, Micropogonias undulatus. A nuclear AR, AR1, was identified in the brain that had high affinity binding sites for testosterone (T; Kd, 1.1 +/- 0.15 nM; binding capacity, 1.4 +/- 0.14 pmol/g tissue; n = 16). A second nuclear AR, AR2, was found in the ovary that had high affinity binding sites for 5alpha-dihydrotestosterone (DHT; Kd, 0.62 +/- 0.1 nM; binding capacity, 0.38 +/- 0.06 pmol/g tissue; n = 14). AR2 has physiochemical properties similar to those of other vertebrate ARs. AR2 has high affinity binding for a broad spectrum of natural and synthetic androgens, including 17alpha-methyl-5alpha-dihydrotestosterone, which has a relative binding affinity of DHT = 100% > T > mibolerone > 11-ketotestosterone = 16%, a rapid association (t1/2, 44 min) and a slow dissociation (t1/2, 45 h) rate, as well as specific binding to purified DNA. The cytosolic AR2 interacts with heat shock proteins in a manner similar to other steroid receptors, as sodium molybdate stabilizes the receptor, and it has a 7.4-7.8S sedimentation coefficient in a 5-20% sucrose gradient. In contrast, AR1 is highly specific for only a few androgens, with T = 100% relative binding affinity >> DHT >> 11-ketotestosterone > mibolerone > 17alpha-methyl-5alpha-dihydrotestosterone = 0, has rapid association (t1/2, 15 min) and dissociation (t1/2, 2.6 +/- 0.7 h) rates, and has specific binding to purified DNA upon heat activation. The cytosolic binding component sediments at 5.6-5.7S in a 5-20% sucrose gradient and is not affected by sodium molybdate, which suggests that AR1 does not interact with heat shock proteins in the usual manner. This is the first report of the presence of two different nuclear ARs displaying markedly different steroid binding specificities within a single vertebrate species.