Division of Molecular Medicine and Gene Therapy, Lund Stem Cell Center, Lund University, Lund, Sweden.
Division of Molecular Hematology, Lund Stem Cell Center, Lund University, Lund, Sweden.
J Biol Chem. 2023 May;299(5):104662. doi: 10.1016/j.jbc.2023.104662. Epub 2023 Mar 29.
To chemically modulate the ubiquitin-proteasome system for the degradation of specific target proteins is currently emerging as an alternative therapeutic modality. Earlier, we discovered such properties of the stem cell-supporting small molecule UM171 and identified that members of the CoREST complex (RCOR1 and LSD1) are targeted for degradation. UM171 supports the in vitro propagation of hematopoietic stem cells by transiently perturbing the differentiation-promoting effects of CoREST. Here, we employed global proteomics to map the UM171-targeted proteome and identified the additional target proteins, namely RCOR3, RREB1, ZNF217, and MIER2. Further, we discovered that critical elements recognized by Cul3 ligase in the presence of UM171 are located within the EGL-27 and MTA1 homology 2 (ELM2) domain of the substrate proteins. Subsequent experiments identified conserved amino acid sites in the N-terminus of the ELM2 domain that are essential for UM171-mediated degradation. Overall, our findings provide a detailed account on the ELM2 degrome targeted by UM171 and identify critical sites required for UM171-mediated degradation of specific substrates. Given the target profile, our results are highly relevant in a clinical context and point towards new therapeutic applications for UM171.
目前，通过化学调节泛素-蛋白酶体系统来降解特定靶蛋白已成为一种替代的治疗方法。早些时候，我们发现了小分子 UM171 的这种特性，并确定了 CoREST 复合物（RCOR1 和 LSD1）成员是其降解的靶标。UM171 通过短暂干扰 CoREST 的促分化作用，支持造血干细胞的体外增殖。在这里，我们采用了全局蛋白质组学来绘制 UM171 靶向的蛋白质组图谱，并鉴定出了其他的靶标蛋白，即 RCOR3、RREB1、ZNF217 和 MIER2。此外，我们发现，在 UM171 存在的情况下，Cul3 连接酶识别的关键元件位于底物蛋白的 EGL-27 和 MTA1 同源 2（ELM2）结构域内。随后的实验确定了 ELM2 结构域 N 端中对 UM171 介导的降解至关重要的保守氨基酸位点。总的来说，我们的研究结果详细说明了 UM171 靶向的 ELM2 降解组，并确定了 UM171 介导特定底物降解所需的关键位点。鉴于其靶标特征，我们的研究结果在临床背景下具有高度相关性，并为 UM171 的新治疗应用指明了方向。
