Elements of the ERAD ubiquitin ligase Doa10 regulating sequential poly-ubiquitylation of its targets.
Elements of the ERAD ubiquitin ligase Doa10 regulating sequential poly-ubiquitylation of its targets.
复制标题
DOI：
10.1016/j.isci.2022.105351
复制
发表时间：
2022-11-18
期刊：
影响因子：
5.8
通讯作者：
Hochstrasser, Mark
中科院分区：
文献类型：
--
作者：
Mehrtash, Adrian B.;Hochstrasser, Mark
在内质网相关降解（ERAD）中，错误折叠的内质网蛋白在泛素化后被蛋白酶体降解。酵母Doa10（人MARCHF6/TEB4）是一种膜嵌入的E3泛素连接酶，与E2s的Ubc6和Ubc7起作用。Ubc6将单个泛素附着在底物上，由Ubc7延伸形成多泛素链。我们发现Doa10的保守c端元件（CTE）促进e3介导的Ubc6活性。经历另一种泛素化机制的Doa10底物在cte突变细胞中仍然被降解。AlphaFold2的结构预测表明，CTE结合在催化RING-CH结构域附近，这意味着在底物泛素化中起直接作用，我们通过基因内抑制证实了这种相互作用。截断分析定义了Doa10的最小e2结合区；结构预测表明，Doa10形成了一个逆转录易位通道，E2s在这里定义的辅因子结合区域内结合。这些结果为Doa10及其潜在的其他连接酶如何与其辅因子相互作用并介导ERAD提供了机制见解。保守的Doa10 c端促进e3介导的Ubc6活性，Doa10的最小e2结合区包括TMs 1-9， Doa10的N端和c端相互作用，可能形成ERAD蛋白通道
In ER-associated degradation (ERAD), misfolded ER proteins are degraded by the proteasome after undergoing ubiquitylation. Yeast Doa10 (human MARCHF6/TEB4) is a membrane-embedded E3 ubiquitin ligase that functions with E2s Ubc6 and Ubc7. Ubc6 attaches a single ubiquitin to substrates, which is extended by Ubc7 to form a polyubiquitin chain. We show the conserved C-terminal element (CTE) of Doa10 promotes E3-mediated Ubc6 activity. Doa10 substrates undergoing an alternative ubiquitylation mechanism are still degraded in CTE-mutant cells. Structure prediction by AlphaFold2 suggests the CTE binds near the catalytic RING-CH domain, implying a direct role in substrate ubiquitylation, and we confirm this interaction using intragenic suppression. Truncation analysis defines a minimal E2-binding region of Doa10; structural predictions suggest that Doa10 forms a retrotranslocation channel and that E2s bind within the cofactor-binding region defined here. These results provide mechanistic insight into how Doa10, and potentially other ligases, interact with their cofactors and mediate ERAD. The conserved Doa10 C-terminus promotes E3-mediated activity of Ubc6 The minimal E2-binding region of Doa10 includes TMs 1–9 The N- and C-terminus of Doa10 interact, likely forming an ERAD protein channel Natural sciencesBiological sciencesMolecular biologyMolecular interaction
登录
查看更多内容
影响因子：
16
作者：
Das, Ranabir;Mariano, Jennifer;Tsai, Yien Che;Kalathur, Ravi C.;Kostova, Zlatka;Li, Jess;Tarasov, Sergey G.;McFeeters, Robert L.;Altieri, Amanda S.;Ji, Xinhua;Byrd, R. Andrew;Weissman, Allan M.
通讯作者：
Weissman, Allan M.
影响因子：
4.8
作者：
JOHNSON, ES;MA, PCM;VARSHAVSKY, A
通讯作者：
VARSHAVSKY, A
影响因子：
7.2
作者：
Braakman, Ineke;Hebert, Daniel N.
通讯作者：
Hebert, Daniel N.
影响因子：
16
作者：
Bagola, Katrin;von Delbrueck, Maximilian;Sommer, Thomas
通讯作者：
Sommer, Thomas
DOI：
10.1083/jcb.201408088
发表时间：
2015-04-27
期刊：
The Journal of cell biology
影响因子：
--
作者：
Habeck G;Ebner FA;Shimada-Kreft H;Kreft SG
通讯作者：
Kreft SG