Antitumor antibiotic fostriecin covalently binds to cysteine-269 residue of protein phosphatase 2A catalytic subunit in mammalian cells
Antitumor antibiotic fostriecin covalently binds to cysteine-269 residue of protein phosphatase 2A catalytic subunit in mammalian cells
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DOI：
10.1016/j.bmc.2009.09.050
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发表时间：
2009-12-01
影响因子：
3.5
通讯作者：
Sugawara, Fumio
中科院分区：
文献类型：
--
作者：
Takeuchi, Toshifumi;Takahashi, Noriyuki;Sugawara, Fumio
Fostriecin是一种磷酸单酯，对小鼠白血病具有良好的抗肿瘤活性，是一种有效的蛋白磷酸酶（PP）2A抑制剂。预计该化合物通过共轭加成反应与PP 2A催化亚基（PP 2Ac）的Cys 269残基在α，β-不饱和内酯处共价结合。然而，这种结合尚未得到实验证明。为了证实这种结合，我们合成了生物素标记的fostriecin（bio-Fos），它对小鼠白血病细胞的增殖具有抑制活性。我们表明，fostriecin直接结合到HeLa S3细胞中的PP 2Ac的下拉测定使用bio-Fos。此外，我们通过基质辅助激光解吸/电离飞行时间质谱分析直接证明了fostriecin与PP 2Ac的Cys 269残基共价结合。根据这些结果，对Fostriecin抑制PP 2A活性的机制进行了讨论。(C)2009爱思唯尔有限公司版权所有。
Fostriecin is a phosphate monoester with excellent antitumor activity against mouse leukemia, and it is a potent inhibitor of protein phosphatase (PP) 2A. This compound has been predicted to covalently bind to the Cys269 residue of the PP2A catalytic subunit (PP2Ac) at the alpha,beta-unsaturated lactone via a conjugate addition reaction. However, this binding has not yet been experimentally proven. To confirm such binding, we synthesized biotin-labeled fostriecin (bio-Fos), which has an inhibitory activity against the proliferation of mouse leukemia cells. We showed that fostriecin directly binds to PP2Ac in HeLa S3 cells by pull-down assays using bio-Fos. Moreover, we directly demonstrated that fostriecin covalently binds to the Cys269 residue of PP2Ac by matrix assisted laser desorption/ionization time-of-flight mass spectrometry analysis. From these results, the inhibitory mechanism of fostriecin on PP2A activity is discussed. (C) 2009 Elsevier Ltd. All rights reserved.