Rines/RNF180, a novel RING finger gene-encoded product, is a membrane-bound ubiquitin ligase
Rines/RNF180, a novel RING finger gene-encoded product, is a membrane-bound ubiquitin ligase
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DOI：
10.1111/j.1365-2443.2008.01169.x
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发表时间：
2008-04-01
期刊：
影响因子：
2.1
通讯作者：
Aruga, Jun
中科院分区：
文献类型：
--
作者：
Ogawa, Miyuki;Mizugishi, Kiyomi;Aruga, Jun
我们发现并鉴定了一个新的RING指基因Rines/RNF 180，该基因在脊椎动物中非常保守。推测Rines基因产物（Rines）包含一个RING指结构域、一个基本卷曲螺旋结构域、一个新保守结构域（DSPRC）和一个预测为跨膜结构域的C端疏水区。在培养的哺乳动物细胞中，在内质网膜/核膜中检测到N-末端表位标记的Rines（Nt-Rines）。Nt-Rines不能被高盐或碱性缓冲液提取，并且在用蛋白酶K处理的完整内质网中降解，表明Nt-Rines是一种完整的膜蛋白，其大部分N-末端区域在细胞质中。Rines在成年小鼠的脑、肾、睾丸和子宫中均有表达，在发育中的透镜和脑中也有表达，特别是在胚胎期大脑皮层的脑室层。在培养的细胞中，Nt-Rines可以结合另一种蛋白质并促进其降解。蛋白酶体抑制剂可抑制降解。此外，Nt-Rines本身被大量泛素化并被蛋白酶体降解。Rines参与泛素-蛋白酶体途径进一步得到了其与UbcH 6泛素缀合酶的结合及其反式泛素化增强活性的支持。这些结果表明，Rines是一种膜结合的E3泛素连接酶。
We identified and characterized a novel RING finger gene, Rines/RNF180, which is well conserved among vertebrates. Putative Rines gene product (Rines) contains a RING finger domain, a basic coiled-coil domain, a novel conserved domain (DSPRC) and a C-terminal hydrophobic region that is predicted to be a transmembrane domain. N-terminally epitope tagged-Rines (Nt-Rines) was detected in the endoplasmic reticulum membrane/nuclear envelope in cultured mammalian cells. Nt-Rines was not extracted by high salt or alkaline buffers and was degraded in intact endoplasmic reticulum treated with proteinase K, indicating that Nt-Rines is an integral membrane protein with most of its N-terminal regions in the cytoplasm. Rines was expressed in brain, kidney, testis and uterus of adult mice, and in developing lens and brain, particularly in the ventricular layer of the cerebral cortex at embryonic stages. In cultured cells, Nt-Rines can bind another protein and promoted its degradation. The degradation was inhibited by proteasomal inhibitors. In addition, Nt-Rines itself was heavily ubiquitinated and degraded by proteasome. The involvement of Rines in the ubiquitin-proteasome pathway was further supported by its binding to the UbcH6 ubiquitin-conjugating enzyme and by its trans-ubiquitination enhancing activities. These results suggest that Rines is a membrane-bound E3 ubiquitin ligase.