RNF138 interacts with RAD51D and is required for DNA interstrand crosslink repair and maintaining chromosome integrity.
RNF138 interacts with RAD51D and is required for DNA interstrand crosslink repair and maintaining chromosome integrity.
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DOI：
10.1016/j.dnarep.2016.04.006
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发表时间：
2016-06
期刊：
影响因子：
3.8
通讯作者：
Pittman DL
中科院分区：
文献类型：
--
作者：
Yard BD;Reilly NM;Bedenbaugh MK;Pittman DL
RAD51 家族对于同源重组 (HR) 介导的 DNA 修复和维持染色体完整性至关重要。 RAD51D 是该家族的第四个成员，是一种已知的卵巢癌易感基因，是修复链间交联 DNA 损伤和保持染色体稳定性所必需的。在本报告中，我们描述了 RNF138 E3 泛素连接酶，它与 RAD51D HR 蛋白相互作用并泛素化。 RNF138 是 E3 连接酶家族的成员，该家族包含氨基末端环指结构域和假定的羧基末端泛素相互作用基序。在哺乳动物细胞中，RNF138 的消耗增加了 RAD51D 蛋白的稳定性，表明 RNF138 控制泛素蛋白酶体介导的 RAD51D 降解。然而，RNF138 的缺失赋予了对 DNA 损伤剂的敏感性，减少了 RAD51 焦点的形成，并增加了染色体的不稳定性。 RNF138 RING Finger 结构域的位点特异性诱变证明 RAD51D 泛素化是必需的。在酵母三杂交测定中，RNF138 的存在还增强了 RAD51D 与已知相互作用的 RAD51 家族成员 XRCC2 之间的相互作用。因此，RNF138 是 HR 介导的 DNA 修复途径中新发现的调节成分，对于理解泛素化如何改变 RAD51 旁系同源蛋白复合物的功能具有重要意义。
The RAD51 family is integral for homologous recombination (HR) mediated DNA repair and maintaining chromosome integrity. RAD51D, the fourth member of the family, is a known ovarian cancer susceptibility gene and required for the repair of interstrand crosslink DNA damage and preserving chromosomal stability. In this report, we describe the RNF138 E3 ubiquitin ligase that interacts with and ubiquitinates the RAD51D HR protein. RNF138 is a member of an E3 ligase family that contains an amino-terminal RING finger domain and a putative carboxyl-terminal ubiquitin interaction motif. In mammalian cells, depletion of RNF138 increased the stability of the RAD51D protein, suggesting that RNF138 governs ubiquitin-proteasome-mediated degradation of RAD51D. However, RNF138 depletion conferred sensitivity to DNA damaging agents, reduced RAD51 focus formation, and increased chromosomal instability. Site-specific mutagenesis of the RNF138 RING finger domain demonstrated that it was necessary for RAD51D ubiquitination. Presence of RNF138 also enhanced the interaction between RAD51D and a known interacting RAD51 family member XRCC2 in a yeast three-hybrid assay. Therefore, RNF138 is a newly identified regulatory component of the HR mediated DNA repair pathway that has implications toward understanding how ubiquitination modifies the functions of the RAD51 paralog protein complex.