Y-box binding protein 1 enhances DNA topoisomerase 1 activity and sensitivity to camptothecin via direct interaction.
Y-box binding protein 1 enhances DNA topoisomerase 1 activity and sensitivity to camptothecin via direct interaction.
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Y-box 结合蛋白 1 通过直接相互作用增强 DNA 拓扑异构酶 1 的活性和对喜树碱的敏感性。
DOI：
10.1186/s13046-014-0112-7
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发表时间：
2014-12-24
期刊：
影响因子：
--
通讯作者：
Kohno K
中科院分区：
文献类型：
--
作者：
Wu Y;Wang KY;Li Z;Liu YP;Izumi H;Uramoto H;Nakayama Y;Ito K;Kohno K
Y-box结合蛋白1(YB-1)通过与多种细胞蛋白的相互作用而具有多效性，其高表达水平使其有可能成为预测肿瘤细胞预后的生物标志物。真核细胞中的DNA拓扑异构酶，如DNA拓扑异构酶1(TOPO1)和DNA拓扑异构酶2(TOPO2)，是在癌细胞中过表达的必需的DNA代谢调节因子，已有多个蛋白质被报道调节其抑制物的酶活性和临床疗效。本研究揭示了YB-1与TOPO1的相互作用，并进一步研究了相互作用中的相关功能和可能的机制。通过免疫共沉淀和GST下拉实验，探讨TOPO1与YB-1的特异性结构域之间的直接联系。通过DNA松弛实验、免疫共沉淀实验和WST-8体外功能得失模型进一步阐明了相互作用的功能。我们发现YB-1与TOPO1(而不是TOPO2)直接相互作用，并促进TOPO1的催化活性。当TOPO1抑制剂喜树碱(CPT)处理癌细胞时，YB-1和TOPO1之间的相互作用增加，但TOPO2抑制剂阿霉素(ADM)处理癌细胞时，YB-1和TOPO1之间的相互作用不增加。此外，我们发现抗氧化剂N-乙酰半胱氨酸可以阻止这种相互作用，而YB-1的下调使细胞对CPT产生抗性。我们的发现表明，核YB-1是TOPO1催化活性的细胞内启动子，通过与TOPO1的直接相互作用来增强CPT的敏感性。
The Y-box binding protein 1 (YB-1) possesses pleiotropic functions through its interactions with various cellular proteins, and its high expression levels make it a potential useful prognostic biomarker for cancer cells. Eukaryotic DNA topoisomerases, such as DNA topoisomerase 1 (TOPO1) and DNA topoisomerase 2 (TOPO2), are the essential DNA metabolism regulators that usually overexpressed in cancer cells, and multiple proteins have been reported to regulate the enzyme activity and the clinical efficacy of their inhibitors. The present study unraveled the interaction of YB-1 with TOPO1, and further investigated the related function and potential mechanisms during the interaction. The direct association of TOPO1 with specific domain of YB-1 was explored by co-immunoprecipitation and GST pull-down assays. The interaction function was further clarified by DNA relaxation assays, co-immunoprecipitation and WST-8 assays with in vitro gain- and loss- of function models. We found that YB-1 interacts directly with TOPO1 (but not with TOPO2) and promotes TOPO1 catalytic activity. Interactions between YB-1 and TOPO1 increased when cancer cells were treated with the TOPO1 inhibitor, camptothecin (CPT), but not with the TOPO2 inhibitor, adriamycin (ADM). Furthermore, we found that the interaction is prevented by pretreatment with the antioxidant agent, N-acetyl cysteine, and that YB-1 downregulation renders cells resistant to CPT. Our findings suggest that nuclear YB-1 serves as an intracellular promoter of TOPO1 catalytic activity that enhances CPT sensitivity through its direct interaction with TOPO1.
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影响因子：
8.8
作者：
Gilbert, D. C.;Chalmers, A. J.;El-Khamisy, S. F.
通讯作者：
El-Khamisy, S. F.
影响因子：
8.4
作者：
Basaki, Yuji;Taguchi, Ken-ichi;Kuwano, Michihiko
通讯作者：
Kuwano, Michihiko
影响因子：
6.4
作者：
Dong, YB;Yang, HL;McMasters, KM
通讯作者：
McMasters, KM
影响因子：
5.7
作者：
Guay, David;Garand, Chantal;Lebel, Michel
通讯作者：
Lebel, Michel
影响因子：
4.8
作者：
Das, Soumita;Chattopadhyay, Ranajoy;Hazra, Tapas K.
通讯作者：
Hazra, Tapas K.