Borodovsky Anna, Ovaa Huib, Kolli Nagamalleswari, Gan-Erdene Tudeviin, Wilkinson Keith D, Ploegh Hidde L, Kessler Benedikt M
Department of Pathology, Harvard Medical School, 200 Longwood Avenue, Boston, MA 02115, USA.
Chem Biol. 2002 Oct;9(10):1149-59. doi: 10.1016/s1074-5521(02)00248-x.
The ubiquitin (Ub)-proteasome system includes a large family of deubiquitinating enzymes (DUBs). Many members are assigned to this enzyme class by sequence similarity but without evidence for biological activity. A panel of novel DUB-specific probes was generated by a chemical ligation method. These probes allowed identification of DUBs and associated components by tandem mass spectrometry, as well as rapid demonstration of enzymatic activity for gene products whose functions were inferred from primary structure. We identified 23 active DUBs in EL4 cells, including the tumor suppressor CYLD1. At least two DUBs tightly interact with the proteasome 19S regulatory complex. An OTU domain-containing protein, with no sequence homology to any known DUBs, was isolated. We show that this polypeptide reacts with the C terminus of Ub, thus demonstrating DUB-like enzymatic activity for this novel superfamily of proteases.
泛素（Ub）-蛋白酶体系统包含一个由去泛素化酶（DUBs）组成的大家族。许多成员通过序列相似性被归为这一酶类，但尚无生物学活性的证据。通过化学连接法生成了一组新型的DUB特异性探针。这些探针可通过串联质谱鉴定DUBs及其相关成分，并能快速证明从一级结构推断其功能的基因产物的酶活性。我们在EL4细胞中鉴定出23种活性DUBs，包括肿瘤抑制因子CYLD1。至少有两种DUBs与蛋白酶体19S调节复合物紧密相互作用。分离出一种与任何已知DUBs均无序列同源性的含OTU结构域的蛋白质。我们表明，该多肽可与Ub的C末端发生反应，从而证明了这种新型蛋白酶超家族具有类似DUB的酶活性。
