A Ubl/ubiquitin switch in the activation of Parkin.
A Ubl/ubiquitin switch in the activation of Parkin.
复制标题
DOI：
10.15252/embj.201592237
复制
发表时间：
2015-10-14
期刊：
影响因子：
--
通讯作者：
Gehring K
中科院分区：
文献类型：
--
作者：
Sauvé V;Lilov A;Seirafi M;Vranas M;Rasool S;Kozlov G;Sprules T;Wang J;Trempe JF;Gehring K
Parkin和PINK 1的突变导致遗传性早发性帕金森病。这两种蛋白质在线粒体质量控制途径中一起起作用，从而PINK 1在受损的线粒体上积累并激活帕金以诱导线粒体自噬。PINK 1激酶活性如何释放帕金自身抑制的泛素连接酶活性仍不清楚。在这里，我们确定磷酸泛素（PUB）和泛素样结构域（UBL）的帕金之间的结合开关作为一个关键因素。通过诱变和小角X射线散射，我们表明，pUb结合帕金的RING 1在一个由His 302和Arg 305形成的位点。pUb结合促进Ubl从RING 1脱离和随后的帕金磷酸化。帕金Δ86-130在2.54 nm分辨率下的晶体结构允许设计从RING 1特异性释放Ubl结构域的突变。这些突变模拟pUb结合并促进帕金磷酸化。E2泛素结合酶UbcH 7结合帕金和帕金E3连接酶活性的测量表明，帕金磷酸化调节E3连接酶活性的pUb结合下游。
Mutations in Parkin and PINK1 cause an inherited early-onset form of Parkinson's disease. The two proteins function together in a mitochondrial quality control pathway whereby PINK1 accumulates on damaged mitochondria and activates Parkin to induce mitophagy. How PINK1 kinase activity releases the auto-inhibited ubiquitin ligase activity of Parkin remains unclear. Here, we identify a binding switch between phospho-ubiquitin (pUb) and the ubiquitin-like domain (Ubl) of Parkin as a key element. By mutagenesis and SAXS, we show that pUb binds to RING1 of Parkin at a site formed by His302 and Arg305. pUb binding promotes disengagement of the Ubl from RING1 and subsequent Parkin phosphorylation. A crystal structure of Parkin Δ86–130 at 2.54 Å resolution allowed the design of mutations that specifically release the Ubl domain from RING1. These mutations mimic pUb binding and promote Parkin phosphorylation. Measurements of the E2 ubiquitin-conjugating enzyme UbcH7 binding to Parkin and Parkin E3 ligase activity suggest that Parkin phosphorylation regulates E3 ligase activity downstream of pUb binding.