Betanska Katarzyna, Nieva Claudia, Spindler-Barth Margarethe, Spindler Klaus-Dieter
Department of General Zoology and Endocrinology, University of Ulm, D-89069 Ulm, Germany.
Arch Insect Biochem Physiol. 2007 Jul;65(3):134-42. doi: 10.1002/arch.20185.
The small G protein Ran, which is important for nucleocytoplasmic shuttling of proteins is present, but does not interact with EcR, Usp, and EcR/Usp. As shown by oligomycin treatment, EcR, Usp, and EcR/Usp import is energy dependent. Export of EcR and EcR/Usp is mediated by exportin-1 (CRM-1) as shown by the inhibiting effect of leptomycin B (LMB). Usp remains in the nucleus for more than 24 h. Nuclear retainment of EcR and Usp is energy dependent as shown by treatment with oligomycin. No export signal could be identified for Usp. The data confirm that EcR and Usp can enter the nucleus independently and that intracellular localization is regulated individually for each receptor. It is also demonstrated that the export signal of EcR is inaccessible after heterodimerization with Usp.
对蛋白质核质穿梭很重要的小G蛋白Ran存在，但不与蜕皮激素受体（EcR）、超气门蛋白（Usp）及EcR/Usp相互作用。如寡霉素处理所示，EcR、Usp及EcR/Usp的入核是能量依赖的。如雷帕霉素B（LMB）的抑制作用所示，EcR和EcR/Usp的出核由出核蛋白1（CRM-1）介导。Usp在细胞核内停留超过24小时。如寡霉素处理所示，EcR和Usp的核内保留是能量依赖的。未鉴定出Usp的出核信号。这些数据证实EcR和Usp可独立进入细胞核，且每个受体的细胞内定位是分别调控的。还证明EcR与Usp异二聚化后其出核信号无法接近。
