Cytoplasmic FKBPs are involved in molting and metamorphosis through regulating the nuclear localization of EcR

RNAi of 2 cytoplasmicFKBPs, specificallyFKBP45 andFKBP12b, prevented the nuclear localization ofEcR, and ultimately affected molting and metamorphosis in insects. AbstractMolting and metamorphosis are important physiological processes in insects that are tightly controlled by ecdysone receptor (EcR) through the 20-hydroxyecdysone (20E) signaling pathway. EcR is a steroid nuclear receptor (SR). Several FK506-binding proteins (FKBPs) have been identified from the mammal SR complex, and are thought to be involved in the subcellular trafficking of SR. However, their roles in insects are poorly understood. To explore whether FKBPs are involved in insect molting or metamorphosis, we injected an FKBP inhibitor (FK506) into a lepidopteran insect,Spodoptera litura, and found that molting was inhibited in 61.11% of the larvae, and that the time for larvae to pupate was significantly extended. A total of 10 FKBP genes were identified from the genome ofS.  litura and were clustered into 2 distinct groups, according to their subcellular localization, with FKBP13 and FKBP14 belonging to the endoplasmic reticulum (ER) group and with the other members belonging to the cytoplasmic (Cy) group. All theCyFKBPs were significantly upregulated in the prepupal or pupal stages, with the opposite being observed for the ER group members. FK506 completely blocked the transfer of EcR to the nucleus under 20E induction, and significantly downregulated the transcriptional expression of many 20E signaling ...

Source: Insect Science - October 12, 2023 Category: Biology Authors: Xian Zhang, Qiao ‐Ran Wang, Qian Wu, Jun Gu, Li‐Hua Huang Tags: ORIGINAL ARTICLE Source Type: research