MRP3蛋白识别与结合底物的机制研究

肿瘤细胞中过表达MRP3蛋白的现象与肿瘤的增殖和多药耐药性相关。MRP3蛋白转运生理性底物LPI会促进肿瘤生长，转运抗肿瘤药物（如依托泊苷，etoposide）可引发肿瘤多药耐药。目前，MRP3识别、结合底物（LPI、etoposide）的机制尚待阐明，MRP3如何与底物结合？MRP3与底物结合后会产生什么的变化？本项目拟利用冷冻电镜单颗粒分析技术，解析MRP3、MRP3-LPI、MRP3- etoposide三种样品的高分辨率结构。分析得到MRP3与底物结合的关键氨基酸位点或结构域，并结合蛋白质定点突变实验验证结构的准确性。通过实施该项目，可阐述MRP3识别、结合LPI与etoposide的机制，充实对MRP3促进肿瘤细胞增殖及引发多药耐药性的认知和理解，为应用MRP3结构信息筛选合适的抗肿瘤药物及后续药物设计提供结构信息，具有重要的指导意义。

The overexpression of MRP3 protein in tumor cells is associated with tumor proliferation and multidrug resistance. Transporting the physiological substrate (LPI), MRP3 can promote tumor growth, and the transporting of anti-tumor drugs (such as etoposide) can induce multidrug resistance. At present, the mechanism of MRP3 recognition and binding substrate remains to be clarified. How does MRP3 bind to substrate? What happens when MRP3 binds to the substrate? We intend to use single particle analysis to determine the high-resolution structure of MRP3, MRP3-LPI and MRP3-etoposide. The key amino acid sites or domains of MRP3 binding with the substrates were analyzed, and the accuracy of the structures was verified by site-directed mutation assay. Through the implementation of this project, the mechanism of MRP3 recognizing and binding to LPI or etoposide can be elaborated, and the cognition and understanding of tumor cell proliferation and multi-drug resistance caused by MRP3 can be enriched. The structural information can be provided for screening suitable anti-tumor drugs and structure-based drug design, which has important guiding significance.