Werner helicase-interacting protein 1 binds polyubiquitin via its zinc finger domain
Werner helicase-interacting protein 1 binds polyubiquitin via its zinc finger domain
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DOI：
10.1074/jbc.m701042200
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发表时间：
2007-08-10
影响因子：
4.8
通讯作者：
Myers, Michael P.
中科院分区：
文献类型：
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作者：
Bish, Rebecca A.;Myers, Michael P.
DNA修复在许多水平上受到泛素化的调控。为了确定DNA修复途径和泛素信号之间的新联系，我们使用质谱法来鉴定与赖氨酸6连接的多聚泛素链相互作用的蛋白质。从这个蛋白质组学筛选，我们确定了DNA修复蛋白WRNIP 1（沃纳解旋酶相互作用蛋白1），沿着核小体组装蛋白1，作为新的泛素相互作用蛋白。我们发现，一个小的锌指结构域在N端的WRNIP1是足够的，必要的非共价泛素结合。这种泛素结合锌指（UBZ）结构域结合多聚泛素，但不结合单泛素，似乎对多聚泛素链连接没有特异性。RAD18中的同源锌指结构域也结合多聚泛素，表明UBZ结构域在DNA修复中具有更广泛的作用。WRNIP 1的泛素结合功能，沿着其先前建立的ATP酶活性，表明WRNIP 1在泛素化蛋白的代谢中起作用。支持这一模型，MGS1，WRNIP1的酵母同源物的删除，减缓泛素周转率，使酵母耐放线菌酮。我们还发现WRNIP1被泛素和SUMO大量修饰，揭示了泛素途径蛋白参与DNA修复调控的复杂层。WRNIP1的新型泛素结合能力揭示了UBZ结构域蛋白在复制后DNA修复中的作用。
DNA repair is regulated on many levels by ubiquitination. In order to identify novel connections between DNA repair pathways and ubiquitin signaling, we used mass spectrometry to identify proteins that interact with lysine 6-linked polyubiquitin chains. From this proteomic screen, we identified the DNA repair protein WRNIP1 (Werner helicase-interacting protein 1), along with nucleosome assembly protein 1, as novel ubiquitin-interacting proteins. We found that a small zinc finger domain at the N terminus of WRNIP1 is sufficient and necessary for noncovalent ubiquitin binding. This ubiquitin-binding zinc finger (UBZ) domain binds polyubiquitin but not monoubiquitin and appears to show no specificity for polyubiquitin chain linkage. A homologous zinc finger domain in RAD18 also binds polyubiquitin, suggesting a wider role for the UBZ domain in DNA repair. The WRNIP1 ubiquitin-binding function, along with its previously established ATPase activity, suggests that WRNIP1 plays a role in the metabolism of ubiquitinated proteins. Supporting this model, deletion of MGS1, the yeast homolog of WRNIP1, slows the rate of ubiquitin turnover, rendering yeast resistant to cycloheximide. We also find that WRNIP1 is heavily modified with ubiquitin and SUMO, revealing complex layers in the involvement of ubiquitin pathway proteins in the regulation of DNA repair. The novel ubiquitin-binding ability of WRNIP1 sheds light on the role of UBZ domain-containing proteins in postreplication DNA repair.