SUMOylation modulates the dual functions of Krüppel homolog 1 in transcriptional regulation of Broad-Complex expression

作者：Qianyu He, Jinxia Chen, Shanshan Chen, Xinyu Gao · 发表于：Journal of Advanced Research · 年份：2025 · DOI：10.1016/j.jare.2025.07.032 · 被引用次数：5 · 研究领域：Neurobiology and Insect Physiology Research、Ubiquitin and proteasome pathways、Developmental Biology and Gene Regulation

INTRODUCTION: Insects undergo intricate metamorphosis processes governed by hormonal regulatory mechanisms, exemplified by the antagonistic actions of 20-hydroxyecdysone (20E) and juvenile hormone (JH). Krüppel homolog 1 (Kr-h1) is a key transcription factor mediating JH's antagonistic effects on 20E. Previous studies have shown that Kr-h1 plays dual roles in regulating the 20E signaling gene Broad-Complex (Br-C), repressing it in larvae and activating it during pupation. However, the mechanisms underlying this dual functionality remain elusive. OBJECTIVES: This study aimed to determine whether SUMOylation, a post-translational modification, functions as part of a molecular switch mechanism for Kr-h1's stage-specific transcriptional roles. METHODS: Using Drosophila melanogaster, we analyzed Kr-h1 SUMOylation dynamics via Western blot, immunoprecipitation combined with Drosophila genetics. Immunostaining, RT-qPCR, and luciferase reporter assays were performed to investigate the impact of SUMOylation on the bidirectional transcriptional regulation of Kr-h1 on Br-C. SUMOylation sites were identified through mutagenesis and bioinformatics. Coimmunoprecipitation and mass spectrometry explored Kr-h1 interactors. Hormonal effects on regulation of Kr-h1 SUMOylation were tested using JH mimic (methoprene) and 20E treatments. RESULTS: Kr-h1 undergoes stage-specific SUMOylation: it is highly SUMOylatedin early third-instar larvae, enabling interaction with the histone methyltransferase ...