Chromatin association of XRCC5/6 in the absence of DNA damage depends on the XPE gene product DDB2.
Chromatin association of XRCC5/6 in the absence of DNA damage depends on the XPE gene product DDB2.
复制标题
在没有DNA损伤的情况下，XRCC5/6的染色质缔合取决于XPE基因产物DDB2。
DOI：
10.1091/mbc.e16-08-0573
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发表时间：
2017-01-01
影响因子：
3.3
通讯作者：
Raychaudhuri P
中科院分区：
文献类型：
--
作者：
Fantini D;Huang S;Asara JM;Bagchi S;Raychaudhuri P
DDB 2是一种多功能蛋白，参与核苷酸切除修复和基因转录调控。在结肠癌细胞中，在没有DNA损伤的情况下，XRCC 5/6的染色质缔合依赖于DDB 2，DDB 2-XRCC 5/6相互作用促进抗血管生成基因SEMA 3A的转录。受损的DNA结合蛋白2（DDB 2）是一种核蛋白，参与核苷酸切除修复和mRNA转录。DDB 2的转录调节功能在结肠癌中是重要的，因为它调节转移。为了表征DDB 2参与转录的机制，我们研究了结肠癌细胞中的蛋白质伴侣。在这里，我们发现DDB 2与XRCC 5/6大量相关，而不涉及CUL 4和DNA-PKcs。诱导DNA双链断裂（DSB）的DNA损伤剂不会影响DDB 2和XRCC 5之间的相互作用。此外，DSB诱导的XRCC 5的核富集或染色质缔合不涉及DDB 2，这表明DDB 2/XRCC 5/6复合物代表了不直接参与DNA断裂修复（NHEJ）的XRCC 5/6的独特池。另一方面，在没有DNA损伤的情况下，XRCC 5的染色质缔合需要DDB 2。我们发现DDB 2将XRCC 5募集到DDB 2刺激的基因SEMA 3A的启动子上。此外，XRCC 5的消耗抑制SEMA 3A表达，而不影响VEGFA（DDB 2的抑制靶标）的表达。总之，我们的研究结果表明，DDB 2是至关重要的染色质协会的XRCC 5/6在DNA损伤的情况下，并提供证据表明，XRCC 5/6是DDB 2在其转录刺激活性的功能伙伴。
DDB2 is a multifunctional protein that participates in both nucleotide excision repair and regulation of gene transcription. In colon cancer cells, chromatin association of XRCC5/6, in the absence of DNA damage, depends on DDB2, and the DDB2–XRCC5/6 interaction promotes the transcription of the antiangiogenic gene SEMA3A. Damaged DNA-binding protein 2 (DDB2), a nuclear protein, participates in both nucleotide excision repair and mRNA transcription. The transcriptional regulatory function of DDB2 is significant in colon cancer, as it regulates metastasis. To characterize the mechanism by which DDB2 participates in transcription, we investigated the protein partners in colon cancer cells. Here we show that DDB2 abundantly associates with XRCC5/6, not involving CUL4 and DNA-PKcs. A DNA-damaging agent that induces DNA double-stranded breaks (DSBs) does not affect the interaction between DDB2 and XRCC5. In addition, DSB-induced nuclear enrichment or chromatin association of XRCC5 does not involve DDB2, suggesting that the DDB2/XRCC5/6 complex represents a distinct pool of XRCC5/6 that is not directly involved in DNA break repair (NHEJ). In the absence of DNA damage, on the other hand, chromatin association of XRCC5 requires DDB2. We show that DDB2 recruits XRCC5 onto the promoter of SEMA3A, a DDB2-stimulated gene. Moreover, depletion of XRCC5 inhibits SEMA3A expression without affecting expression of VEGFA, a repression target of DDB2. Together our results show that DDB2 is critical for chromatin association of XRCC5/6 in the absence of DNA damage and provide evidence that XRCC5/6 are functional partners of DDB2 in its transcriptional stimulatory activity.