Basis for metabolite-dependent Cullin-RING ligase deneddylation by the COP9 signalosome
Basis for metabolite-dependent Cullin-RING ligase deneddylation by the COP9 signalosome
复制标题
COP9 信号体依赖代谢物的 Cullin-RING 连接酶去甲基化的基础。
DOI：
10.1073/pnas.1911998117
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发表时间：
2020-02-25
影响因子：
11.1
通讯作者：
Rao, Feng
中科院分区：
文献类型：
--
作者：
Lin, Hong;Zhang, Xiaozhe;Rao, Feng
Cullin-RING连接酶（CRL）是最大的泛蛋白E3家族，通过neddylation激活并受去核酶COP 9信号体（CSN）调节。肌醇多磷酸代谢产物促进CRL-CSN复合物的形成，但作用机制尚不清楚。在这里，我们提供的结构和遗传证据支持肌醇六磷酸（IP 6）作为一个通用的CSN辅因子招募CRL。我们确定了与CSN亚基2（CSN 2）复合的IP 6的晶体结构，基于此，我们在CRL 4A-CSN复合物的冷冻电子显微镜图中鉴定了IP 6对应的电子密度。IP 6与CSN 2和Rbx 1/Roc 1的保守赖氨酸残基形成的同源口袋结合，从而加强CRL-CSN相互作用，从CRL中去除E2 CDC 34/UBE 2 R，并促进CRL去卷曲化。IP 6结合缺陷型Csn 2（K70 E/K70 E）敲入小鼠是胚胎致死的。相同的突变使粟酒裂殖酵母Csn 2无法拯救csn 2缺失酵母的紫外线超敏反应。这些数据表明。CRL从E2-结合的活性状态到CSN-结合的螯合状态的转变关键地由界面IP 6小分子辅助，其代谢可以耦合到CRL-CSN复合物动力学。
The Cullin-RING ligases (CRLs) are the largest family of ubiquitin E3s activated by neddylation and regulated by the deneddylase COP9 signalosome (CSN). The inositol polyphosphate metabolites promote the formation of CRL-CSN complexes, but with unclear mechanism of action. Here, we provide structural and genetic evidence supporting inositol hexakisphosphate (IP6) as a general CSN cofactor recruiting CRLs. We determined the crystal structure of IP6 in complex with CSN subunit 2 (CSN2), based on which we identified the IP6-corresponding electron density in the cryoelectron microscopy map of a CRL4A-CSN complex. IP6 binds to a cognate pocket formed by conserved lysine residues from CSN2 and Rbx1/Roc1, thereby strengthening CRL-CSN interactions to dislodge the E2 CDC34/UBE2R from CRL and to promote CRL deneddylation. IP6 binding-deficient Csn2(K70E/K70E) knockin mice are embryonic lethal. The same mutation disabled Schizosaccharomyces pombe Csn2 from rescuing UV-hypersensitivity of csn2-null yeast. These data suggest. that CRL transition from the E2-bound active state to the CSN-bound sequestered state is critically assisted by an interfacial IP6 small molecule, whose metabolism may be coupled to CRL-CSN complex dynamics.