Structure of the Rpn13-Rpn2 complex provides insights for Rpn13 and Uch37 as anticancer targets.
Structure of the Rpn13-Rpn2 complex provides insights for Rpn13 and Uch37 as anticancer targets.
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DOI：
10.1038/ncomms15540
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发表时间：
2017-06-09
影响因子：
16.6
通讯作者：
Walters KJ
中科院分区：
文献类型：
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作者：
Lu X;Nowicka U;Sridharan V;Liu F;Randles L;Hymel D;Dyba M;Tarasov SG;Tarasova NI;Zhao XZ;Hamazaki J;Murata S;Burke TR Jr;Walters KJ
蛋白酶体-泛素受体hRpn13/Adrm1结合并激活去泛素酶Uch37/UCHL5，并被双苄基哌酮RA190靶向，从而限制小鼠异种移植物的肿瘤生长。在这里，我们用hRpn2的一个片段作为其蛋白酶体的对接位点来解决hRpn13的结构；富含脯氨酸的c端hRpn2延伸延伸穿过泛素结合hRpn13 Pru结构域的狭窄峡谷，阻断ra190结合表面。生物物理分析和基于细胞的实验表明，hRpn13比RA190更倾向于与hRpn2和蛋白酶体结合。hRpn13也存在于蛋白酶体外，可能对RA190敏感。RA190不影响hRpn13与Uch37的相互作用，而是直接结合Uch37并使其失活。HCT116细胞中hRpn13的缺失消除了ra190诱导的蛋白酶体底物积累。我们认为RA190通过平行机制作用于hRpn13和Uch37，在蛋白酶体上，RA190失活的Uch37不能分解hRpn13结合的泛素链。在蛋白酶体中，Rpn2为底物受体Rpn13提供对接位点。本文作者介绍了人类Rpn13 Pru结构域与Rpn2结合位点的结构，并提供了Rpn13靶向分子RA190的作用模式，该分子具有抗癌特性。
Proteasome–ubiquitin receptor hRpn13/Adrm1 binds and activates deubiquitinating enzyme Uch37/UCHL5 and is targeted by bis-benzylidine piperidone RA190, which restricts cancer growth in mice xenografts. Here, we solve the structure of hRpn13 with a segment of hRpn2 that serves as its proteasome docking site; a proline-rich C-terminal hRpn2 extension stretches across a narrow canyon of the ubiquitin-binding hRpn13 Pru domain blocking an RA190-binding surface. Biophysical analyses in combination with cell-based assays indicate that hRpn13 binds preferentially to hRpn2 and proteasomes over RA190. hRpn13 also exists outside of proteasomes where it may be RA190 sensitive. RA190 does not affect hRpn13 interaction with Uch37, but rather directly binds and inactivates Uch37. hRpn13 deletion from HCT116 cells abrogates RA190-induced accumulation of substrates at proteasomes. We propose that RA190 targets hRpn13 and Uch37 through parallel mechanisms and at proteasomes, RA190-inactivated Uch37 cannot disassemble hRpn13-bound ubiquitin chains. In the proteasome, Rpn2 provides the docking site for substrate receptor Rpn13. Here the authors present the structure of human Rpn13 Pru domain bound to its binding site in Rpn2 and provide insights into the mode of action for Rpn13-targeting molecule RA190, which has anticancer properties.