RNF144A, an E3 ubiquitin ligase for DNA-PKcs, promotes apoptosis during DNA damage
RNF144A, an E3 ubiquitin ligase for DNA-PKcs, promotes apoptosis during DNA damage
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DOI：
10.1073/pnas.1323107111
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发表时间：
2014-07-01
影响因子：
11.1
通讯作者：
Lin, Weei-Chin
中科院分区：
文献类型：
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作者：
Ho, Shiuh-Rong;Mahanic, Christina S.;Lin, Weei-Chin
一些环指（RBR）结构域蛋白，如Parkin和Parc，已被证明是参与重要生物过程的E3连接酶。在这里，我们确定了一个很差的特点RBR蛋白，环指蛋白144 A（RNF 144 A），作为第一个，据我们所知，哺乳动物E3泛素连接酶的DNA-PKcs。我们发现DNA损伤以p53依赖的方式诱导RNF 144 A的表达。RNF 144 A主要定位于细胞质囊泡和质膜，并与细胞质DNA依赖性蛋白激酶催化亚基（DNA-PKcs）相互作用。DNA-PKcs在非同源末端连接DNA修复途径中起关键作用，并在DNA损伤期间提供促存活信号。我们发现RNF 144 A在体外和体内诱导DNA-PKcs的泛素化，并促进其降解。RNF 144 A的消耗导致DNA-PKcs水平的增加和对DNA损伤剂的抗性，这被DNA-PK抑制剂逆转。综上所述，我们的数据表明，RNF 144 A可能参与p53介导的细胞凋亡，通过下调DNA-PKcs时，细胞遭受持续或严重的DNA损伤的侮辱。
Several ring between ring fingers ( RBR) -domain proteins, such as Parkin and Parc, have been shown to be E3 ligases involved in important biological processes. Here, we identify a poorly characterized RBR protein, Ring Finger protein 144A ( RNF144A), as the first, to our knowledge, mammalian E3 ubiquitin ligase for DNA-PKcs. We show that DNA damage induces RNF144A expression in a p53-dependent manner. RNF144A is mainly localized in the cytoplasmic vesicles and plasma membrane and interacts with cytoplasmic DNA-dependent protein kinase, catalytic subunit (DNA-PKcs). DNA-PKcs plays a critical role in the nonhomologous end-joining DNA repair pathway and provides prosurvival signaling during DNA damage. We show that RNF144A induces ubiquitination of DNA-PKcs in vitro and in vivo and promotes its degradation. Depletion of RNF144A leads to an increased level of DNA-PKcs and resistance to DNA damaging agents, which is reversed by a DNA-PK inhibitor. Taken together, our data suggest that RNF144A may be involved in p53-mediated apoptosis through down-regulation of DNA-PKcs when cells suffer from persistent or severe DNA damage insults.