Bruton's tyrosine kinase revealed as a negative regulator of Wnt-beta-catenin signaling.
Bruton's tyrosine kinase revealed as a negative regulator of Wnt-beta-catenin signaling.
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DOI：
10.1126/scisignal.2000230
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发表时间：
2009-05-26
影响因子：
7.3
通讯作者：
Moon RT
中科院分区：
文献类型：
--
作者：
James RG;Biechele TL;Conrad WH;Camp ND;Fass DM;Major MB;Sommer K;Yi X;Roberts BS;Cleary MA;Arthur WT;MacCoss M;Rawlings DJ;Haggarty SJ;Moon RT
Wnt是一种分泌型配体，可激活多种受体介导的信号转导级联反应。在成人中需要通过β-连环蛋白的稳态Wnt信号传导，因为β-连环蛋白功能的升高或减弱与多种疾病有关。为了有助于这一途径的蛋白质和药理学调节剂的鉴定，我们描述了一种组合筛选，该组合筛选将来自已知生物活性化合物的高通量筛选的数据与独立集中的小干扰RNA筛选合并。每次筛选都独立地揭示了布鲁顿酪氨酸激酶（BTK）作为Wnt-β-连环蛋白信号传导的抑制剂。在人结肠直肠癌细胞、人B细胞、斑马鱼胚胎和来源于具有突变BTK基因的X连锁无丙种球蛋白血症患者的细胞中BTK功能的丧失导致Wnt-β-连环蛋白信号传导升高，证实BTK充当该途径的负调节剂。从亲和纯化-质谱和生化结合研究中，我们发现BTK直接与Wnt-β-连环蛋白信号传导的核组分CDC 73相互作用。此外，我们发现BTK在没有刺激的情况下增加了CDC 73的丰度，并且CDC 73在人结直肠癌细胞和B细胞中充当β-连环蛋白介导的转录的阻遏物。
Wnts are secreted ligands that activate several receptor-mediated signal transduction cascades. Homeostatic Wnt signaling through β-catenin is required in adults, because either elevation or attenuation of β-catenin function has been linked to diverse diseases. To contribute to the identification of both protein and pharmacological regulators of this pathway, we describe a combinatorial screen that merged data from a high-throughput screen of known bioactive compounds with an independent focused small interfering RNA screen. Each screen independently revealed Bruton’s tyrosine kinase (BTK) as an inhibitor of Wnt–β-catenin signaling. Loss of BTK function in human colorectal cancer cells, human B cells, zebrafish embryos, and cells derived from X-linked agammaglobulinemia patients with a mutant BTK gene resulted in elevated Wnt–β-catenin signaling, confirming that BTK acts as a negative regulator of this pathway. From affinity purification–mass spectrometry and biochemical binding studies, we found that BTK directly interacts with a nuclear component of Wnt–β-catenin signaling, CDC73. Further, we show that BTK increased the abundance of CDC73 in the absence of stimulation and that CDC73 acted as a repressor of β-catenin-mediated transcription in human colorectal cancer cells and B cells.