Aberrant activation of Notch signaling, mediated by the Notch intracellular domain (NICD), is linked to certain types of cancer. The NICD is released through γ-secretase-mediated cleavage of the Notch receptor. Therefore, development of a γ-secretase inhibitor (GSI) represents an anticancer strategy. Here we report the cryo-electron microscopy structures of human γ-secretase bound individually to five clinically tested GSIs (RO4929097, crenigacestat, BMS906024, nirogacestat and MK-0752) at overall resolutions of 2.4–3.0 Å. Three of the five GSIs are in active anticancer clinical trials, while nirogacestat was recently approved. Each of these GSIs similarly occupies the substrate-binding site of presenilin 1 but shows characteristic differences in detailed recognition pattern. The size and shape of the binding pocket are induced by the bound GSI. Analysis of these structural features suggest strategies for modification of the GSI with improved inhibition potency.

由 Notch 胞内结构域 （NICD） 介导的 Notch 信号转导的异常激活与某些类型的癌症有关。NICD 通过 γ-secretase 介导的 Notch 受体裂解释放。因此，γ-分泌酶抑制剂 （GSI） 的开发代表了一种抗癌策略。在这里，我们报告了人 γ-分泌酶的冷冻电子显微镜结构，它们分别与五个临床测试的 GSI（RO4929097、crenigacestat、BMS906024、nirogacestat 和 MK-0752）结合，总分辨率为 2.4–3.0 Å。5 个 GSI 中有 3 个正在进行积极的抗癌临床试验，而 nirogacestat 最近获得批准。这些 GSI 中的每一个都类似地占据早老素 1 的底物结合位点，但在详细识别模式方面表现出特征差异。结合口袋的大小和形状由结合的 GSI 诱导。对这些结构特征的分析提出了提高抑制效力的 GSI 修饰策略。