Y654 of β-catenin is essential for FLT3/ITD-related tyrosine phosphorylation and nuclear localization of β-catenin
Y654 of β-catenin is essential for FLT3/ITD-related tyrosine phosphorylation and nuclear localization of β-catenin
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DOI：
10.1111/j.1600-0609.2011.01738.x
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发表时间：
2012-04-01
影响因子：
3.1
通讯作者：
Naoe, Tomoki
中科院分区：
文献类型：
--
作者：
Kajiguchi, Tomohiro;Katsumi, Akira;Naoe, Tomoki
β-连环蛋白作为粘附连接调节中的关键效应物以及转录共激活物发挥双重作用。β-连环蛋白的酪氨酸磷酸化影响许多类型的人类癌细胞中的细胞粘附、迁移和基因转录，包括具有FLT 3内部串联重复的急性髓性白血病细胞（FLT 3/ITD-AML）。在这里，我们研究了三个酪氨酸残基（Y86，Y142和Y 654）在β-连环蛋白和致癌FLT 3/ITD激酶之间的关系。在使用表达FLT 3/ITD和Wt或突变的β-连环蛋白的COS-7细胞的实验中，FLT 3/ITD磷酸化Y 654，并且该残基对于通过FLT 3/ITD进行的β-连环蛋白核定位是必需的。启动子-报告基因分析表明β-catenin的Y 654磷酸化与TCF转录活性密切相关。使用重组FLT 3和包括Y 654的生物素化β-连环蛋白肽的体外激酶测定显示FLT 3直接磷酸化β-连环蛋白的Y 654。这些结果解释了FLT 3/ITD如何影响β-连环蛋白的酪氨酸磷酸化、核定位和转录活性。靶向Y 654磷酸化可能会导致FLT 3/ITD-AML治疗新方法的开发。
beta-Catenin plays a dual role as a key effecter in the regulation of adherens junctions as well as a transcriptional co-activator. Tyrosine phosphorylation of beta-catenin affects the cell adhesion, migration, and gene transcription in many types of human cancer cells, including acute myeloid leukemia cells with FLT3 internal tandem duplication (FLT3/ITD-AML). Here, we investigated the relationship between three tyrosine residues (Y86, Y142, and Y654) in beta-catenin and oncogenic FLT3/ITD kinase. In the experiments using COS-7 cells expressing FLT3/ITD and Wt or mutant beta-catenin, FLT3/ITD phosphorylated Y654, and this residue was essential for beta-catenins nuclear localization by FLT3/ITD. Promoter-reporter assays demonstrated that Y654 phosphorylation of beta-catenin was closely related to TCF transcriptional activity. In vitro kinase assays, using recombinant FLT3 and biotinylated beta-catenin peptide including Y654 showed that FLT3 directly phosphorylated Y654 of beta-catenin. These results explain how FLT3/ITD affects the tyrosine phosphorylation, nuclear localization, and transcriptional activity of beta-catenin. Targeting Y654 phosphorylation may lead to the development of novel approaches to therapy for FLT3/ITD-AML.