The molecular basis of substrate specificity for a small molecule ubiquitin ligase complex

小分子泛素连接酶复合物底物特异性的分子基础

基本信息

批准号：
9763326
负责人：
Tyler B Faust
金额：
$ 6.16万
依托单位：
DANA-FARBER CANCER INST
依托单位国家：
美国
项目类别：
财政年份：
2018
资助国家：
美国
起止时间：
2018-08-01 至 2021-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9763326
关键词：
Address Binding Biochemical Cell Line Cells Chemicals Complex Detection Development Disease Goals Human Immunomodulators In Vitro Knowledge Length Libraries Ligands Ligase Malignant Neoplasms Mass Spectrum Analysis Mediating Methods Modification Molecular Mus Mutation Post-Translational Protein Processing Protein Splicing Proteins Public Health RNA Recognition Motif RNA Splicing RNA-Binding Proteins Recruitment Activity Research Specificity Structural Models Structure Substrate Interaction Substrate Specificity Sulfonamides Surface System Thalidomide Therapeutic Intervention Ubiquitin Ubiquitination Work analog anticancer activity cell type design exhaustion experimental study in vivo insight lenalidomide multicatalytic endopeptidase complex mutant novel novel drug class novel therapeutics pomalidomide protein degradation protein expression receptor recruit small molecule therapeutic development transcription factor ubiquitin ligase ubiquitin-protein ligase

Address Binding Biochemical Cell Line Cells Chemicals Complex Detection Development Disease Goals Human Immunomodulators In Vitro Knowledge Length Libraries Ligands Ligase Malignant Neoplasms Mass Spectrum Analysis Mediating Methods Modification Molecular Mus Mutation Post-Translational Protein Processing Protein Splicing Proteins Public Health RNA Recognition Motif RNA Splicing RNA-Binding Proteins Recruitment Activity Research Specificity Structural Models Structure Substrate Interaction Substrate Specificity Sulfonamides Surface System Thalidomide Therapeutic Intervention Ubiquitin Ubiquitination Work analog anticancer activity cell type design exhaustion experimental study in vivo insight lenalidomide multicatalytic endopeptidase complex mutant novel novel drug class novel therapeutics pomalidomide protein degradation protein expression receptor recruit small molecule therapeutic development transcription factor ubiquitin ligase ubiquitin-protein ligase

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项目摘要

Project Summary Post-translational modification of proteins with ubiquitin leads to their degradation by the proteasome. Ubiquitin ligases confer substrate specificity in the ubiquitin-proteasome system by binding target proteins and presenting them for ubiquitination. While thousands of proteins in the cell are ubiquitinated by over 600 ligases, the direct targets of ubiquitin ligases are still difficult to identify. As such, the general principles of substrate recognition remain unclear. Remarkably, a class of small molecules termed IMiDs (immunomodulatory drugs), including thalidomide, lenalidomide and pomalidomide, can bind ubiquitin ligases and alter their substrate specificity by inducing the degradation of novel targets. Recently, another class of compounds (sulfonamides) has been shown to act in an analogous manner by inducing the degradation of the splicing factor RBM39. The long-term goal of the proposal is to understand how small molecules can rewire ubiquitin ligase selectivity from endogenous targets to neo-substrates. The objective of the application is to determine how the sulfonamide compound E7820 alters the target specificity of the ubiquitin ligase substrate receptor DCAF15. The central hypothesis is that E7820 binding to DCAF15 generates a novel small molecule-protein interaction surface that provides specificity for substrates containing an RNA recognition motif (RRM), including RBM39. To address this hypothesis, Aim 1 will utilize a combination of biochemical and structural methods to provide a molecular basis for E7820-mediated recruitment of RBM39 to CRL4DCAF15 for degradation. Visualizing the CRL4DCAF15-E7820-RBM39 complex will reveal how the substrate interaction surface of DCAF15 is repurposed for novel targets. Structure-guided mutants will be generated to support this molecular picture in vivo. Aim 2 will employ a degradation screen of a human RRM-GFP library, which will uncover the full repertoire of E7820- dependent CRL4DCAF15 substrates. Any RRMs stabilized by E7820 treatment are likely natural targets of the CRL4DCAF15 ligase. Insight from these studies will provide a framework for the design of compounds that can alter selectivity of other ubiquitin ligases and facilitate the discovery of natural ligands that similarly regulate ligase-substrate interactions. Finally, targeted protein degradation is an exciting new avenue of therapeutic development, and the proposed work will accelerate the design of new classes of drugs that can degrade a broader range of targets, enabling novel therapies for currently incurable diseases.

项目摘要用泛素对蛋白质的翻译后修饰导致蛋白酶体的降解。泛素连接酶通过结合靶蛋白和呈现它们以进行泛素化。虽然细胞中成千上万的蛋白质被超过600个连接酶泛素化，但泛素连接酶的直接靶标仍然难以识别。因此，底物的一般原则识别仍然不清楚。值得注意的是，一类称为Imids（免疫调节药物）的小分子，包括沙利度胺，莱纳略胺和果皮胺可以结合泛素连接酶并改变其底物通过诱导新目标的降解来特异性。最近，另一种化合物（磺酰胺）已显示通过诱导剪接因子RBM39的降解来以类似的方式起作用。这该提案的长期目标是了解小分子如何从泛素连接酶中重新从内源性目标到新材料。应用的目的是确定磺酰胺如何复合E7820改变了泛素连接酶底物受体DCAF15的靶特异性。中央假设是E7820与DCAF15结合产生了一种新型的小分子 - 蛋白质相互作用表面，该表面是为包含RNA识别基序（RRM）（包括RBM39）的底物提供了特异性。为了解决这一假设，AIM 1将利用生化和结构方法的组合来提供 E7820介导的RBM39募集到CRL4DCAF15降解的分子基础。可视化 CRL4DCAF15-E7820-RBM39复合物将揭示DCAF15的底物相互作用表面如何重新使用对于新颖的目标。将生成结构引导的突变体，以支持体内这种分子图片。目标2 将采用人类RRM-GFP库的退化屏幕，该库将揭示E7820-的完整曲目依赖性CRL4DCAF15底物。 E7820处理稳定的任何RRM都可能是自然靶标的 CRL4DCAF15连接酶。这些研究的洞察力将为可以设计的化合物设计框架改变其他泛素连接酶的选择性，并促进发现类似调节的天然配体连接酶 - 基底相互作用。最后，靶向蛋白质降解是一种令人兴奋的治疗方法开发，拟议的工作将加速新的药物的设计，这些药物可以降解范围更广泛的目标，为目前无法治愈的疾病提供新的疗法。