Biofisika Institute (UPV/EHU, CSIC) and Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), Leioa, Spain.
Department of Biomedicine, University of Bergen, Bergen, Norway.
Sci Rep. 2017 Oct 24;7(1):13959. doi: 10.1038/s41598-017-14497-4.
Nucleophosmin (NPM) is a nucleolar protein involved in ribosome assembly and cell homeostasis. Mutations in the C-terminal domain of NPM that impair native folding and localization are associated with acute myeloid leukemia (AML). We have performed a high-throughput screening searching for compounds that stabilize the C-terminal domain. We identified three hit compounds which show the ability to increase the thermal stability of both the C-terminal domain as well as full-length NPM. The best hit also seemed to favor folding of an AML-like mutant. Computational pocket identification and molecular docking support a stabilization mechanism based on binding of the phenyl/benzene group of the compounds to a particular hydrophobic pocket and additional polar interactions with solvent-accessible residues. Since these results indicate a chaperoning potential of our candidate hits, we tested their effect on the subcellular localization of AML-like mutants. Two compounds partially alleviated the aggregation and restored nucleolar localization of misfolded mutants. The identified hits appear promising as pharmacological chaperones aimed at therapies for AML based on conformational stabilization of NPM.
核仁磷酸蛋白（Nucleophosmin，NPM）是一种参与核糖体组装和细胞内稳态的核仁蛋白。NPM 中 C 末端结构域的突变会破坏其天然折叠和定位，与急性髓系白血病（acute myeloid leukemia，AML）有关。我们进行了高通量筛选，寻找能够稳定 C 末端结构域的化合物。我们确定了三种有潜力的化合物，它们能够提高 C 末端结构域以及全长 NPM 的热稳定性。其中最好的一种化合物似乎还能促进 AML 样突变体的折叠。计算口袋鉴定和分子对接支持一种基于化合物的苯/苯环基团与特定疏水性口袋结合以及与可及溶剂残基的额外极性相互作用的稳定机制。由于这些结果表明我们的候选化合物具有分子伴侣的潜力，我们测试了它们对 AML 样突变体亚细胞定位的影响。两种化合物部分缓解了聚集并恢复了错误折叠突变体的核仁定位。鉴定出的化合物具有很大的应用潜力，可作为基于 NPM 构象稳定的 AML 治疗的药理学伴侣。
