Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, MA, USA; Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA, USA.
Cutaneous Biology Research Center, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA.
Cell Stem Cell. 2020 May 7;26(5):675-692.e8. doi: 10.1016/j.stem.2020.03.002. Epub 2020 Apr 6.
Intestinal homeostasis is tightly regulated by complex yet poorly understood signaling networks. Here, we demonstrate that Lats1/2, the core Hippo kinases, are essential to maintain Wnt pathway activity and intestinal stem cells. Lats1/2 deletion leads to loss of intestinal stem cells but drives Wnt-uncoupled crypt expansion. To explore the function of downstream transcriptional enhanced associate domain (TEAD) transcription factors, we identified a selective small-molecule reversible inhibitor of TEAD auto-palmitoylation that directly occupies its lipid-binding site and inhibits TEAD-mediated transcription in vivo. Combining this chemical tool with genetic and proteomics approaches, we show that intestinal Wnt inhibition by Lats deletion is Yes-associated protein (YAP)/transcriptional activator with PDZ-binding domain (TAZ) dependent but TEAD independent. Mechanistically, nuclear YAP/TAZ interact with Groucho/Transducin-Like Enhancer of Split (TLE) to block Wnt/T-cell factor (TCF)-mediated transcription, and dual inhibition of TEAD and Lats suppresses Wnt-uncoupled Myc upregulation and epithelial over-proliferation in Adenomatous polyposis coli (APC)-mutated intestine. Our studies highlight a pharmacological approach to inhibit TEAD palmitoylation and have important implications for targeting Wnt and Hippo signaling in human malignancies.
肠道内稳态受到复杂但尚未完全理解的信号网络的严格调控。在这里,我们证明 Lats1/2(Hippo 激酶的核心)对于维持 Wnt 通路活性和肠道干细胞是必不可少的。Lats1/2 的缺失会导致肠道干细胞丢失,但会驱动 Wnt 解偶联的隐窝扩张。为了探索下游转录增强相关结构域(TEAD)转录因子的功能,我们鉴定了一种选择性小分子可逆 TEAD 自身棕榈酰化抑制剂,该抑制剂可直接占据其脂质结合位点并抑制体内 TEAD 介导的转录。结合这种化学工具以及遗传和蛋白质组学方法,我们表明 Lats 缺失导致的肠道 Wnt 抑制依赖于 Yes 相关蛋白 (YAP)/含有 PDZ 结合域的转录激活因子(TAZ),但不依赖于 TEAD。在机制上,核 YAP/TAZ 与 Groucho/Transducin-Like Enhancer of Split (TLE) 相互作用,阻断 Wnt/T 细胞因子 (TCF) 介导的转录,双重抑制 TEAD 和 Lats 可抑制 APC 突变肠道中 Wnt 解偶联 Myc 的上调和上皮过度增殖。我们的研究强调了一种抑制 TEAD 棕榈酰化的药理学方法,对于靶向人类恶性肿瘤中的 Wnt 和 Hippo 信号具有重要意义。