Power R F, Mani S K, Codina J, Conneely O M, O'Malley B W
Department of Cell Biology, Baylor College of Medicine, Houston, TX 77030.
Science. 1991 Dec 13;254(5038):1636-9. doi: 10.1126/science.1749936.
The current view of how steroid hormone receptors affect gene transcription is that these receptors, on binding ligand, change to a state in which they can interact with chromatin and regulate transcription of target genes. Receptor activation is believed to be dependent only on this ligand-binding event. Selected steroid hormone receptors can be activated in a ligand-independent manner by a membrane receptor agonist, the neurotransmitter dopamine. In vitro, dopamine faithfully mimicked the effect of progesterone by causing a translocation of chicken progesterone receptor (cPR) from cytoplasm to nucleus. Dual activation by progesterone and dopamine was dissociable, and a serine residue in the cPR was identified that is not necessary for progesterone-dependent activation of cPR, but is essential for dopamine activation of this receptor.
目前关于类固醇激素受体如何影响基因转录的观点是，这些受体在结合配体后，会转变为一种能够与染色质相互作用并调节靶基因转录的状态。受体激活被认为仅依赖于这种配体结合事件。某些类固醇激素受体可被膜受体激动剂、神经递质多巴胺以不依赖配体的方式激活。在体外，多巴胺通过促使鸡孕酮受体（cPR）从细胞质转运至细胞核，忠实地模拟了孕酮的作用。孕酮和多巴胺的双重激活是可分离的，并且在cPR中鉴定出一个丝氨酸残基，它对于cPR的孕酮依赖性激活并非必需，但对于该受体的多巴胺激活至关重要。
