A FancD2-monoubiquitin fusion reveals hidden functions of Fanconi anemia core complex in DNA repair
A FancD2-monoubiquitin fusion reveals hidden functions of Fanconi anemia core complex in DNA repair
复制标题
DOI：
10.1016/j.molcel.2005.08.018
复制
发表时间：
2005-09-16
期刊：
影响因子：
16
通讯作者：
Takata, M
中科院分区：
文献类型：
--
作者：
Matsushita, N;Kitao, H;Takata, M
在DNA损伤反应中，范可尼贫血（FA）蛋白FancD 2靶向染色质并在其单泛素化后形成核灶，这一过程可能由FA核心复合物催化。在这里，我们表明，鸡FancD 2-泛素融合蛋白，携带一个Lys-Arg取代去除天然monoubiquitination网站（D2 KR-Ub），可以逆转顺铂超敏反应和本地化FANCD 2缺陷的DT 40细胞的染色质。重要的是，染色质靶向依赖于三个核心复合物组分以及可能指导蛋白质-蛋白质相互作用的泛素的疏水表面。此外，D2 KR-组蛋白H2 B的组成性染色质结合融合物可以补充FANCD 2-而不是FANCC-，FANCG-或FANCL-缺陷细胞中的顺铂敏感性。因此，这些核心复合物组分在DNA修复中具有额外的功能，其独立于FancD 2的单泛素化和染色质靶向。这些结果定义了FancD 2单泛素化的功能后果，并揭示了FA蛋白核心复合物先前隐藏的功能。
In DNA damage responses, the Fanconi anemia (FA) protein, FancD2, is targeted to chromatin and forms nuclear foci following its monoubiquitination, a process likely catalyzed by the FA core complex. Here, we show that a chicken FancD2-ubiquitin fusion protein, carrying a Lys-Arg substitution removing the natural monoubiquitination site (D2KR-Ub), could reverse cisplatin hypersensitivity and localize to chromatin in FANCD2-deficient DT40 cells. Importantly, the chromatin targeting was dependent on three core complex components as well as the hydrophobic surface of ubiquitin that may direct protein-protein interactions. Furthermore, a constitutively chromatin bound fusion of D2KR-histone H2B could complement cisplatin sensitivity in FANCD2- but not FANCC-, FANCG-, or FANCL-deficient cells. Thus these core complex components have an additional function in the DNA repair, which is independent of the monoubiquitination and chromatin targeting of FancD2. These results define functional consequences of FancD2 monoubiquitination and reveal previously hidden functions for the FA protein core complex.