Notch受体的激活由胞内膜蛋白酶γ-分泌酶调控，该酶切割并释放出Notch胞内域（Nicd），从而调节基因转录。虽然γ-分泌酶切割是必要的，但我们证明它对于Notch的激活是不充分的，需要囊泡转运。在这里，我们报道二价金属转运蛋白1（Dmt1, Slc11A2）作为一个新的和必需的Notch信号传导调节因子。Dmt1缺陷的细胞在Notch信号传导中存在缺陷，并且内质体溶酶体转运和功能受到了干扰。Dmt1编码两种不同的亚型，即具有和不具有铁响应元件（ire）的亚型。我们展示了Dmt1-ire和Dmt1+ire的亚型特异性沉默在细胞系和肠道器官样体的Notch依赖性细胞命运方面具有相反的影响。Dmt1-ire的丧失抑制了Notch的激活并促进分化，而Dmt1+ire的丧失导致了Notch的激活并维持干细胞-前体细胞命运。Dmt1亚型表达与Apc缺陷的肠道器官样体和人类结直肠癌中的Notch和Wnt信号传导相关。一致地，Dmt1-ire沉默诱导结直肠癌细胞中的Notch依赖性分化。这些数据确定了Dmt1亚型作为控制正常细胞和肿瘤细胞Notch细胞命运决策的二进制开关。本文受版权保护。版权所有。

Notch receptor activation is regulated by the intramembrane protease γ-secretase, which cleaves and liberates the Notch intracellular domain (Nicd) that regulates gene transcription. While γ-secretase cleavage is necessary, we demonstrate it is insufficient for Notch activation and requires vesicular trafficking. Here, we report Divalent metal transporter 1 (Dmt1, Slc11A2) as a novel and essential regulator of Notch signalling. Dmt1-deficient cells are defective in Notch signalling and have perturbed endolysosomal trafficking and function. Dmt1 encodes for two isoforms, with and without an iron response element (ire). We show that isoform-specific silencing of Dmt1-ire and Dmt1+ire have opposite consequences on Notch-dependent cell fates in cell lines and intestinal organoids. Loss of Dmt1-ire suppresses Notch activation and promotes differentiation, whereas loss of Dmt1+ire causes Notch activation and maintains stem-progenitor cell fates. Dmt1 isoform expression correlates with Notch and Wnt signalling in Apc-deficient intestinal organoids and human colorectal cancers. Consistently Dmt1-ire silencing induces Notch-dependent differentiation in colorectal cancer cells. These data identify Dmt1 isoforms as binary switches controlling Notch cell fate decisions in normal and tumour cells.This article is protected by copyright. All rights reserved.