Unique proteasome subunit Xrpn10c is a specific receptor for the antiapoptotic ubiquitin-like protein Scythe
Unique proteasome subunit Xrpn10c is a specific receptor for the antiapoptotic ubiquitin-like protein Scythe
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DOI：
10.1111/j.1742-4658.2005.05032.x
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发表时间：
2005-12-01
期刊：
影响因子：
5.4
通讯作者：
Kawahara, H
中科院分区：
文献类型：
--
作者：
Kikukawa, Y;Minami, R;Kawahara, H
26 S蛋白酶体的Rpn 10亚基可以通过泛素相互作用基序（UIMs）与多聚泛素化和/或泛素样蛋白结合。脊椎动物Rpn 10由五种不同的剪接异构体组成，但这些变体的具体功能在很大程度上仍然未知。我们在这里报告，非洲爪蟾Rpn 10的替代产品之一，命名为Xrpn 10 c，功能作为一个特定的受体镰刀/BAG-6，据报道，调节收割机诱导的细胞凋亡。缺失分析显示，镰刀至少有两个不同的结构域负责其结合Xrpn 10 c。相反，Xrpn 10 c有一个不依赖UIM的Scythe结合位点。在非洲爪蟾胚胎中缺乏Xrpn 10 c结合结构域的镰刀突变蛋白的强制表达诱导了不适当的胚胎死亡，而野生型镰刀没有显示出任何异常。结果表明，Xrpn 10 c结合位点的镰刀作为一个重要的部分连接泛素/蛋白酶体机制的控制适当的胚胎发育。
The Rpn10 subunit of the 26S proteasome can bind to polyubiquitinoylated and/or ubiquitin-like proteins via ubiquitin-interacting motifs (UIMs). Vertebrate Rpn10 consists of five distinct spliced isoforms, but the specific functions of these variants remain largely unknown. We report here that one of the alternative products of Xenopus Rpn10, named Xrpn10c, functions as a specific receptor for Scythe/BAG-6, which has been reported to regulate Reaper-induced apoptosis. Deletional analyses revealed that Scythe has at least two distinct domains responsible for its binding to Xrpn10c. Conversely, an Xrpn10c has a UIM-independent Scythe-binding site. The forced expression of a Scythe mutant protein lacking Xrpn10c-binding domains in Xenopus embryos induces inappropriate embryonic death, whereas the wild-type Scythe did not show any abnormality. The results indicate that Xrpn10c-binding sites of Scythe act as an essential segment linking the ubiquitin/proteasome machinery to the control of proper embryonic development.