Structural insights into Parkin substrate lysine targeting from minimal Miro substrates
Structural insights into Parkin substrate lysine targeting from minimal Miro substrates
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DOI：
10.1038/srep33019
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发表时间：
2016-09-08
影响因子：
4.6
通讯作者：
Rice, Sarah E.
中科院分区：
文献类型：
--
作者：
Klosowiak, Julian L.;Park, Sungjin;Rice, Sarah E.
遗传性帕金森病通常是由蛋白激酶PINK 1或E3泛素连接酶Parkin突变引起的，它们共同作用以消除受损的线粒体。PINK 1磷酸化帕金蛋白和泛素，以刺激线粒体外膜表面上数十种蛋白质的泛素化。然而，帕金识别特定蛋白质进行修饰的机制在很大程度上尚未探索。在这里，我们表明，C-末端GTdR（cGTdR）的帕金主要底物人米罗是必要的，足够的有效的泛素化。我们提出了几个新的X射线晶体结构的人Miro 1和Miro 2，揭示底物识别和泛素转移是特定的蛋白质结构域和赖氨酸残基。我们还提供了证据表明，帕金底物识别功能上是独立的底物修饰。最后，我们表明，优先考虑修改特定的赖氨酸侧链的cGTdR（K572）在人类Miro 1是依赖于它的位置和化学微环境。通过磷酸化或通过pUb的结合激活帕金是K572修饰的优先级所需的，这表明帕金激活和底物特异性的获得是耦合的。
Hereditary Parkinson's disease is commonly caused by mutations in the protein kinase PINK1 or the E3 ubiquitin ligase Parkin, which function together to eliminate damaged mitochondria. PINK1 phosphorylates both Parkin and ubiquitin to stimulate ubiquitination of dozens of proteins on the surface of the outer mitochondrial membrane. However, the mechanisms by which Parkin recognizes specific proteins for modification remain largely unexplored. Here, we show that the C-terminal GTPase (cGTPase) of the Parkin primary substrate human Miro is necessary and sufficient for efficient ubiquitination. We present several new X-ray crystal structures of both human Miro1 and Miro2 that reveal substrate recognition and ubiquitin transfer to be specific to particular protein domains and lysine residues. We also provide evidence that Parkin substrate recognition is functionally separate from substrate modification. Finally, we show that prioritization for modification of a specific lysine sidechain of the cGTPase (K572) within human Miro1 is dependent on both its location and chemical microenvironment. Activation of Parkin by phosphorylation or by binding of pUb is required for prioritization of K572 for modification, suggesting that Parkin activation and acquisition of substrate specificity are coupled.