A Redox-Linked Novel Pathway for Arsenic-Mediated RET Tyrosine Kinase Activation
A Redox-Linked Novel Pathway for Arsenic-Mediated RET Tyrosine Kinase Activation
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DOI：
10.1002/jcb.22550
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发表时间：
2010-05-15
影响因子：
4
通讯作者：
Kawamoto, Yoshiyuki
中科院分区：
文献类型：
--
作者：
Kato, Masashi;Takeda, Kozue;Kawamoto, Yoshiyuki
我们检测了砷对RET原癌基因（c-RET蛋白酪氨酸激酶）和RET致癌基因（RET- men2a和RET- ptc1蛋白酪氨酸激酶）产物活性的生化影响。砷通过促进二硫键介导的c-RET蛋白二聚化活化c-RET激酶。砷进一步激活了RET-MEN2A激酶，与c-RET激酶活性相比，基因突变已经增加了3- 10倍，促进了RET-MEN2A蛋白的二硫键介导的二聚化（超激活）。砷还通过促进二硫键介导的RET-PTC1蛋白二聚化，增加细胞外结构域缺失的RET-PTC1激酶活性。砷增加了RET-PTC1激酶活性，丙氨酸替代半胱氨酸365 （C365）促进了二聚体的形成，而丙氨酸替代半胱氨酸376 （C376）则没有。我们的研究结果表明，砷介导的RET激酶活性的调节依赖于RET蛋白的构象变化，通过调节RET蛋白胞内结构域的特殊半胱氨酸（RET- ptc1蛋白中C376的相关半胱氨酸）。此外，砷通过增加巯基依赖性二聚体的形成，增强了免疫沉淀RET蛋白的活性。在砷培养的细胞中检测到砷（14.2 μ M），砷与细胞内RET的直接关联可能调节二聚体的形成。因此，我们证明了砷介导的RET原癌基因和癌基因产物激活的一种新的氧化还原连接机制。j .细胞。中国生物医学工程学报，2010,31(2):379 - 379。(C) 2010 Wiley-Liss, Inc。
We examined the biochemical effects of arsenic on the activities of RET proto-oncogene (c-RET protein tyrosine kinases) and RET oncogene (RET-MEN2A and RET-PTC1 protein tyrosine kinases) products. Arsenic activated c-RET kinase with promotion of disulfide bond-mediated dimerization of c-RET protein. Arsenic further activated RET-MEN2A kinase, which was already 3- to 10-fold augmented by genetic mutation compared with c-RET kinase activity, with promotion of disulfide bond-mediated dimerization of RET-MEN2A protein (superactivation). Arsenic also increased extracellular domain-deleted RET-PTC1 kinase activity with promotion of disulfide bond-mediated dimerization of RET-PTC1 protein. Arsenic increased RET-PTC1 kinase activity with cysteine 365 (C365) replaced by alanine with promotion of dimer formation but not with cysteine 376 (C376) replaced by alanine. Our results suggest that arsenic-mediated regulation of RET kinase activity is dependent on conformational change of RET protein through modulation of a special cysteine sited at the intracellular domain in RET protein (relevant cysteine of C376 in RET-PTC1 protein). Moreover, arsenic enhanced the activity of immunoprecipitated RET protein with increase in thiol-dependent dimer formation. As arsenic (14.2 mu M) was detected in the cells cultured with arsenic (100 direct association between arsenic and RET in the cells might modulate dimer formation. Thus, we demonstrated a novel redox-linked mechanism of activation of arsenic-mediated RET proto-oncogene and oncogene products. J. Cell. Biochem. 110: 399-407, 2010. (C) 2010 Wiley-Liss, Inc.