Julio Ashley R, Shikwana Flowreen, Truong Cindy, Burton Nikolas R, Dominguez Emil R, Turmon Alexandra C, Cao Jian, Backus Keriann M
Department of Biological Chemistry, David Geffen School of Medicine, UCLA, Los Angeles, CA, USA.
Department of Chemistry and Biochemistry, UCLA, Los Angeles, CA, USA.
Nat Chem Biol. 2025 May;21(5):693-705. doi: 10.1038/s41589-024-01760-9. Epub 2024 Oct 24.
Covalent modulators and covalent degrader molecules have emerged as drug modalities with tremendous therapeutic potential. Toward realizing this potential, mass spectrometry-based chemoproteomic screens have generated proteome-wide maps of potential druggable cysteine residues. However, beyond these direct cysteine-target maps, the full scope of direct and indirect activities of these molecules on cellular processes and how such activities contribute to reported modes of action, such as degrader activity, remains to be fully understood. Using chemoproteomics, we identified a cysteine-reactive small molecule degrader of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nonstructural protein 14 (nsp14), which effects degradation through direct modification of cysteines in both nsp14 and in host protein disulfide isomerases. This degrader activity was further potentiated by generalized electrophile-induced global protein ubiquitylation, proteasome activation and widespread aggregation and depletion of host proteins, including the formation of stress granules. Collectively, we delineate the wide-ranging impacts of cysteine-reactive electrophilic compounds on cellular proteostasis processes.
共价调节剂和共价降解分子已成为具有巨大治疗潜力的药物形式。为了实现这一潜力，基于质谱的化学蛋白质组学筛选生成了全蛋白质组范围内潜在可成药半胱氨酸残基的图谱。然而，除了这些直接的半胱氨酸靶点图谱外，这些分子在细胞过程中的直接和间接活性的全貌，以及这些活性如何促成所报道的作用模式，如降解活性，仍有待充分了解。利用化学蛋白质组学，我们鉴定出一种针对严重急性呼吸综合征冠状病毒2（SARS-CoV-2）非结构蛋白14（nsp14）的半胱氨酸反应性小分子降解剂，它通过直接修饰nsp14和宿主蛋白二硫键异构酶中的半胱氨酸来实现降解。普遍的亲电试剂诱导的全局蛋白质泛素化、蛋白酶体激活以及宿主蛋白的广泛聚集和消耗，包括应激颗粒的形成，进一步增强了这种降解活性。我们共同描绘了半胱氨酸反应性亲电化合物对细胞蛋白质稳态过程的广泛影响。
