Otubains: a new family of cysteine proteases in the ubiquitin pathway
Otubains: a new family of cysteine proteases in the ubiquitin pathway
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DOI：
10.1038/sj.embor.embor824
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发表时间：
2003-05-01
期刊：
影响因子：
7.7
通讯作者：
Chroboczek, J
中科院分区：
文献类型：
--
作者：
Balakirev, MY;Tcherniuk, SO;Chroboczek, J
泛素（ubiquitin，Ub）对细胞蛋白质的修饰是真核生物蛋白质稳定性和功能的重要基础。蛋白质泛素化是一个动态和可逆的过程;附着的Ub可以通过去泛素化酶（DUBs）去除，DUBs是一组异质的半胱氨酸蛋白酶，可以精确地在Ub-蛋白质键处切割蛋白质。两个家庭的DUBs已确定以前。在这里，我们描述了新的，高度特异性的Ub异肽酶，没有序列同源性已知DUBs，但属于OTU（卵巢肿瘤）蛋白质超家族。通过使用DUB特异性抑制剂Ub醛（Ubal）的亲和纯化，从HeLa细胞中分离出两种新蛋白。我们将这些蛋白质命名为otubain 1和otubain 2，即OTU结构域UbaI结合蛋白。otubains的功能分析显示OTU结构域含有活性半胱氨酸蛋白酶位点。
The modification of cellular proteins by ubiquitin (Ub) is an important event that underlies protein stability and function in eukaryotes. Protein ubiquitylation is a dynamic and reversible process; attached Ub can be removed by deubiquitylating enzymes (DUBs), a heterogeneous group of cysteine proteases that cleave proteins precisely at the Ub-protein bond. Two families of DUBs have been identified previously. Here, we describe new, highly specific Ub iso-peptidases, that have no sequence homology to known DUBs, but which belong to the OTU ( ovarian tumour) superfamily of proteins. Two novel proteins were isolated from HeLa cells by affinity purification using the DUB-specific inhibitor, Ub aldehyde (Ubal). We have named these proteins otubain 1 and otubain 2, for OTU-domain Ubal-binding protein. Functional analysis of otubains shows that the OTU domain contains an active cysteine protease site.