The human Dcn1-like protein DCNL3 promotes Cul3 neddylation at membranes
The human Dcn1-like protein DCNL3 promotes Cul3 neddylation at membranes
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DOI：
10.1073/pnas.0812528106
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发表时间：
2009-07-28
影响因子：
11.1
通讯作者：
Peter, Matthias
中科院分区：
文献类型：
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作者：
Meyer-Schaller, Nathalie;Chou, Yang-Chieh;Peter, Matthias
基于Cullin（Cul）的E3泛素连接酶通过Nedd 8与Cul蛋白的连接而被激活。在酵母中，Dcn 1（Cul neddylation 1蛋白缺陷）通过与其Cul底物和Nedd 8 E2 Ubc 12相互作用而发挥支架样Nedd 8 E3连接酶的功能。人类细胞表达5种Dcn 1样（DCNL）蛋白，每种蛋白都含有C-末端增强neddylation结构域，但具有不同的氨基末端延伸。虽然含有UBA的DCNL 1和DCNL 2可能是酵母Dcn 1的功能同源物，但DCNL 3也与人类Cul相互作用，并且能够补充酵母dcn 1 Delta细胞的neddylation缺陷。通过RNAi下调DCNL 3可降低Cul neddylation，而DCNL 3结合缺陷的Cul 3突变体的过表达可干扰Cul 3体内功能。有趣的是，DCNL 3通过N端保守的脂质修饰基序在质膜上积累。膜结合的DCNL 3能够将Cul 3募集到膜上，并且对于体内Cul 3 neddylation具有重要功能。我们的结论是，DCNL蛋白的功能作为非冗余Cul Nedd 8-E3连接酶。此外，在哺乳动物Dcn 1同源物的N末端的多样化可能有助于底物特异性，通过调节其亚细胞定位。
Cullin (Cul)-based E3 ubiquitin ligases are activated through the attachment of Nedd8 to the Cul protein. In yeast, Dcn1 (defective in Cul neddylation 1 protein) functions as a scaffold-like Nedd8 E3-ligase by interacting with its Cul substrates and the Nedd8 E2 Ubc12. Human cells express 5 Dcn1-like (DCNL) proteins each containing a C-terminal potentiating neddylation domain but distinct amino-terminal extensions. Although the UBA-containing DCNL1 and DCNL2 are likely functional homologues of yeast Dcn1, DCNL3 also interacts with human Culs and is able to complement the neddylation defect of yeast dcn1 Delta cells. DCNL3 down-regulation by RNAi decreases Cul neddylation, and overexpression of a Cul3 mutant deficient in DCNL3 binding interferes with Cul3 function in vivo. Interestingly, DCNL3 accumulates at the plasma membrane through a conserved, lipid-modified motif at the N terminus. Membrane-bound DCNL3 is able to recruit Cul3 to membranes and is functionally important for Cul3 neddylation in vivo. We conclude that DCNL proteins function as nonredundant Cul Nedd8-E3 ligases. Moreover, the diversification of the N termini in mammalian Dcn1 homologues may contribute to substrate specificity by regulating their subcellular localization.