The Octopus vulgaris estrogen receptor is a constitutive transcriptional activator:: Evolutionary and functional implications
The Octopus vulgaris estrogen receptor is a constitutive transcriptional activator:: Evolutionary and functional implications
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DOI：
10.1210/en.2006-0363
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发表时间：
2006-08-01
期刊：
影响因子：
4.8
通讯作者：
Thornton, Joseph W.
中科院分区：
文献类型：
--
作者：
Keay, June;Bridgham, Jamie T.;Thornton, Joseph W.
类固醇激素如雌激素和雄激素是包括脊椎动物和软体动物在内的多种动物类群的生殖、生理和发育的重要调节剂。类固醇激素受体，介导这些激素的经典细胞反应，被认为是脊椎动物特异性的，这使得类固醇在无脊椎动物中作用的分子机制尚未解决。最近，雌激素受体（ER）的直系同源物被分离出的海兔，但受体的功能意义尚不清楚，因为雌激素和其他类固醇是不知道是重要的，在该物种。此外，发现Aparasia ER是一种组成型转录激活因子，但目前还不清楚ER的雌激素独立性是Aparasia特有的新奇现象还是软体动物更古老的特征。在这里，我们报告的第一ER直系同源物的分离和功能特性，从无脊椎动物中产生雌激素，并发挥明显的作用，头足类章鱼寻常。我们表明，章鱼ER是一个强大的组成性转录激活剂从典型的雌激素反应元件。该受体不结合雌二醇，对雌激素和其他脊椎动物类固醇激素无反应。这些特点是类似的，观察到的Aaplasia ER和支持的假设，不断发展的ER获得组成活动深入的软体动物谱系。雌激素在章鱼和其他软体动物中的明显生殖作用不太可能由ER介导，并且可能通过古老的非ER介导的途径发生。
Steroid hormones such as estrogens and androgens are important regulators of reproduction, physiology, and development in a variety of animal taxa, including vertebrates and mollusks. Steroid hormone receptors, which mediate the classic cellular responses to these hormones, were thought to be vertebrate specific, which left the molecular mechanisms of steroid action in invertebrates unresolved. Recently an estrogen receptor (ER) ortholog was isolated from the sea hare Aplysia californica, but the functional significance of the receptor was unclear because estrogens and other steroids are not known to be important in that species. Furthermore, the Aplysia ER was found to be a constitutive transcriptional activator, but it was unclear whether the estrogen independence of the ER was an Aplysia-specific novelty or a more ancient character general to the mollusks. Here we report on the isolation and functional characterization of the first ER ortholog from an invertebrate in which estrogens are produced and play an apparent role, the cephalopod Octopus vulgaris. We show that the Octopus ER is a strong constitutive transcriptional activator from canonical estrogen response elements. The receptor does not bind estradiol and is unresponsive to estrogens and other vertebrate steroid hormones. These characteristics are similar to those observed with the Aplysia ER and support the hypothesis that the evolving ER gained constitutive activity deep in the mollusk lineage. The apparent reproductive role of estrogens in Octopus and other mollusks is unlikely to be mediated by the ER and may take place through an ancient, non-ER-mediated pathway.