Biology Department, 45 Water Street, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA.
Gen Comp Endocrinol. 2011 Sep 1;173(2):346-55. doi: 10.1016/j.ygcen.2011.06.010. Epub 2011 Jun 22.
In arthropods, ecdysteroids regulate molting by activating a heterodimer formed by the ecdysone receptor (EcR) and retinoid X receptor (RXR). While this mechanism is similar in insects and crustaceans, variation in receptor splicing, dimerization and ligand affinity adds specificity to molting processes. This study reports the EcR and RXR sequences from American lobster, a commercially and ecologically important crustacean. We cloned two EcR splice variants, both of which specifically bind ponasterone A, and two RXR variants, both of which enhance binding of ponasterone A to the EcR. Lobster EcR has high affinity for ponasterone A and muristerone and moderately high affinity for the insecticide tebufenozide. Bisphenol A, diethyl phthalate, and two polychlorinated biphenyls (PCB 29 and PCB 30), environmental chemicals shown to interfere with crustacean molting, showed little or no affinity for lobster EcR. These studies establish the molecular basis for investigation of lobster ecdysteroid signaling and signal disruption by environmental chemicals.
在节肢动物中，蜕皮激素通过激活由蜕皮激素受体 (EcR) 和视黄酸 X 受体 (RXR) 形成的异二聚体来调节蜕皮。虽然这种机制在昆虫和甲壳动物中相似，但受体剪接、二聚化和配体亲和力的变化为蜕皮过程增加了特异性。本研究报告了美洲龙虾（一种具有商业和生态重要性的甲壳类动物）的 EcR 和 RXR 序列。我们克隆了两种 EcR 剪接变体，它们都特异性结合波那甾酮 A，以及两种 RXR 变体，它们都增强了波那甾酮 A 与 EcR 的结合。龙虾 EcR 对波那甾酮 A 和 muristerone 具有高亲和力，对杀虫剂噻虫嗪具有中等亲和力。双酚 A、邻苯二甲酸二乙酯和两种多氯联苯（PCB 29 和 PCB 30）是已知会干扰甲壳动物蜕皮的环境化学物质，对龙虾 EcR 的亲和力很小或没有。这些研究为研究龙虾蜕皮激素信号转导和环境化学物质对信号的干扰奠定了分子基础。
