Structure-guided probing of the leukotriene C4 binding site in human multidrug resistance protein 1 (MRP1; ABCC1)
Structure-guided probing of the leukotriene C4 binding site in human multidrug resistance protein 1 (MRP1; ABCC1)
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DOI：
10.1096/fj.201900140r
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发表时间：
2019-10-01
期刊：
影响因子：
4.8
通讯作者：
Cole, Susan P. C.
中科院分区：
文献类型：
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作者：
Conseil, Gwenaelle;Arama-Chayoth, May;Cole, Susan P. C.
人类多药耐药蛋白 1 (hMRP1) 转运蛋白与癌症多药耐药性以及涉及其生理底物谷胱甘肽 (GSH) 结合的白三烯 C-4 (LTC4) 的免疫反应有关。 LTC4 结合 hMRP1 上的二分位点，最近 LTC4 结合牛 Mrp1 的冷冻电子显微镜结构将其描述为由带正电的口袋和疏水 (H) 口袋组成，分别结合 LTC4 的 GSH 部分和围绕脂肪酸部分。在这里，我们表明 H 袋 hMRP1-Met (1093) 的单个 Ala 和 Leu 取代对 LTC4 结合或转运没有影响。雌酮 3-硫酸盐转运也不受影响，但两个 hMRP1-Met(1093) 突变消除了雌二醇葡萄糖苷酸转运，表明这些类固醇缀合物具有彼此不同且与 LTC4 不同的结合位点。为了消除 hMRP1 对 LTC4 的转运，需要对 3 个 H 袋残基进行突变 (W553/M1093/W1246A)，这表明 H 袋氨基酸是 hMRP1 对 LTC4 与单独 GSH 的亲和力截然不同的关键。与有机阴离子转运不同，Ala 取代 Met 比 Leu 取代更能降低 hMRP1 介导的耐药性 (1093)。尽管我们的研究结果普遍支持 H 口袋残基结合 LTC4 脂质尾部的结构，但它们在结合雌激素和抗癌药物转运中的关键和差异作用仍然无法解释。-Conseil, G., Arama-Chayoth, M., Tsfadia, Y., Cole, S. P. C. 人类多药耐药蛋白 1 (MRP1; 中白三烯 C-4 结合位点的结构引导探测) ABCC1）。
The human multidrug resistance protein 1 (hMRP1) transporter is implicated in cancer multidrug resistance as well as immune responses involving its physiologic substrate, glutathione (GSH)-conjugated leukotriene C-4 (LTC4). LTC4 binds a bipartite site on hMRP1, which a recent cryoelectron microscopy structure of LTC4-bound bovine Mrp1 depicts as composed of a positively charged pocket and a hydrophobic (H) pocket that binds the GSH moiety and surrounds the fatty acid moiety, respectively, of LTC4. Here, we show that single Ala and Leu substitutions of H-pocket hMRP1-Met(1093) have no effect on LTC4 binding or transport. Estrone 3-sulfate transport is also unaffected, but both hMRP1-Met(1093) mutations eliminate estradiol glucuronide transport, demonstrating that these steroid conjugates have binding sites distinct from each other and from LTC4. To eliminate LTC4 transport by hMRP1, mutation of 3 H-pocket residues was required (W553/M1093/W1246A), indicating that H-pocket amino acids are key to the vastly different affinities of hMRP1 for LTC4 vs. GSH alone. Unlike organic anion transport, hMRP1-mediated drug resistance was more diminished by Ala than Leu substitution of Met(1093). Although our findings generally support a structure in which H-pocket residues bind the lipid tail of LTC4, their critical and differential role in the transport of conjugated estrogens and anticancer drugs remains unexplained.-Conseil, G., Arama-Chayoth, M., Tsfadia, Y., Cole, S. P. C. Structure-guided probing of the leukotriene C-4 binding site in human multidrug resistance protein 1 (MRP1; ABCC1).