G-Protein Pathway Suppressor 2 (GPS2) 是一种由 E2 泛素结合酶 Ubc13 介导的非蛋白水解 K63 泛素化的抑制剂。先前的研究已将 GPS2 介导的泛素化限制与不同组织和细胞类型之间的胰岛素信号传导、炎症反应和线粒体-核通讯的调节联系起来。然而，缺乏对 GPS2/Ubc13 活动目标的详细了解。在这里，我们剖析了小鼠胚胎成纤维细胞和人乳腺癌细胞中 GPS2 调节的 K63 泛素组，意外地发现线粒体外膜上参与 RNA 结合和翻译的蛋白质富集。对 GPS2 介导的调节的选定靶标（包括 RNA 结合蛋白 PABPC1 和翻译因子 RPS1、RACK1 和 eIF3M）的验证揭示了一种通过非蛋白水解泛素化调节核编码线粒体蛋白翻译的线粒体特异性策略。通过基因删除或应激诱导的核易位来消除 GPS2 介导的抑制，可促进选定 mRNA 的导入偶联翻译，从而导致适应性抗氧化程序的表达增加。鉴于 GPS2 在核线粒体通讯中的作用，这些发现揭示了一个通过空间协调转录和翻译来调节线粒体基因表达的精致调控网络。版权所有 © 2024。由 Elsevier Ltd 出版。

G-Protein Pathway Suppressor 2 (GPS2) is an inhibitor of non-proteolytic K63 ubiquitination mediated by the E2 ubiquitin-conjugating enzyme Ubc13. Previous studies have associated GPS2-mediated restriction of ubiquitination with the regulation of insulin signaling, inflammatory responses and mitochondria-nuclear communication across different tissues and cell types. However, a detailed understanding of the targets of GPS2/Ubc13 activity is lacking. Here, we have dissected the GPS2-regulated K63 ubiquitome in mouse embryonic fibroblasts and human breast cancer cells, unexpectedly finding an enrichment for proteins involved in RNA binding and translation on the outer mitochondrial membrane. Validation of selected targets of GPS2-mediated regulation, including the RNA-binding protein PABPC1 and translation factors RPS1, RACK1 and eIF3M, revealed a mitochondrial-specific strategy for regulating the translation of nuclear-encoded mitochondrial proteins via non-proteolytic ubiquitination. Removal of GPS2-mediated inhibition, either via genetic deletion or stress-induced nuclear translocation, promotes the import-coupled translation of selected mRNAs leading to the increased expression of an adaptive antioxidant program. In light of GPS2 role in nuclear-mitochondria communication, these findings reveal an exquisite regulatory network for modulating mitochondrial gene expression through spatially coordinated transcription and translation.Copyright © 2024. Published by Elsevier Ltd.