SINE化合物通过异质机制激活出口蛋白1的降解
Casey E Wing1, Ho Yee Joyce Fung1,2, Bert Kwanten3
1Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX, USA.
Nature chemical biology
|November 25, 2025
概括
核出口选择性抑制剂 (SINEs) 通过异质机制触发癌细胞蛋白出口蛋白1 (XPO1) 的降解. 这一过程涉及ASB8的招募,并利用原生细胞通路,扩大向蛋白质降解策略.
科学领域:
- 分子生物学分子生物学
- 结构生物学 结构生物学
- 在瘤学瘤学.
背景情况:
- 在癌细胞中过度表达出口因1 (XPO1/CRM1) 会导致核出口货物的错位.
- 选择性核出口抑制剂 (SINEs),如selinexor,通过阻止XPO1-货物相互作用来恢复核局部化.
- 此外,SINE还会诱导由库林-RING E3酶 (CRL) 基质受体ASB8.8介导的XPO1降解.
研究的目的:
- 阐明SINE诱导的XPO1降解的结构基础和机制.
- 研究ASB8在SINE介导的XPO1降解中的作用.
- 为了确定合成XPO1抑制剂是否模仿本源细胞降解途径.
主要方法:
- 电子显微镜 (cryo-EM) 用于确定与SINE结合的XPO1.1结合的ASB8的结构.
- 生物化学测试以评估蛋白质-蛋白质相互作用和无处不在.
- 研究由内源性化合物诱导的ASB8介导的降解.
主要成果:
- 冷-EM结构显示ASB8与SINE结合时暴露的神秘XPO1位点结合.
- SINEs独立于ASB8结合XPO1,启动一个用于高亲和度ASB8招募的全oster机制.
- 通过CRL途径,SINEs诱导XPO1的无化和降解.
- 内源性伊塔科纳酸衍生物4-octyl伊塔科纳酸也会触发ASB8介导的XPO1降解.
结论:
- SINEs通过一种新的全性机制诱导XPO1降解,与典型的分子合物不同.
- 这种机制涉及ASB8的招聘到SINE-bound XPO1.
- 合成XPO1抑制剂利用原生细胞降解途径,扩大向蛋白质降解策略超出现有的模式.
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