Regulation of receptor protein-tyrosine phosphatase α by oxidative stress
Regulation of receptor protein-tyrosine phosphatase α by oxidative stress
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DOI：
10.1093/emboj/21.4.493
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发表时间：
2002-02-15
期刊：
影响因子：
11.4
通讯作者：
den Hertog, J
中科院分区：
文献类型：
--
作者：
Blanchetot, C;Tertoolen, LGJ;den Hertog, J
两个蛋白酪氨酸磷酸酶（PTP）结构域的存在是大多数跨膜受体PTP （RPTPs）的一个显著特征。通常失活的膜-远端PTP结构域（RPTP-D2）的功能尚不清楚。在这里，我们报道了RPTPalpha中间隔区（Sp）和c端之间的分子内相互作用禁止分子间相互作用。有趣的是，H2O2、UV和热休克等应激因子诱导了RPTPalpha和RPTPalpha- spd2之间可逆的、依赖自由基的分子间相互作用，表明RPTPalpha- spd2的构象和结合发生了可诱导的转换。RPTPalpha- spd2的催化位点Cys723是H2O2作用于RPTPalpha所需的半胱氨酸。通过荧光共振能量转移检测，H2O2在体内诱导了快速、可逆、依赖于cys723的构象变化，在单个嵌合蛋白中，青色荧光蛋白（CFP）和黄色荧光蛋白（YFP）位于RPTPalpha-SpD2的两侧。重要的是，H2O2处理稳定了RPTPalpha二聚体，导致失活。我们提出了一个氧化应激诱导RPTPalpha- d2构象变化的模型，导致RPTPalpha二聚体稳定，从而抑制RPTPalpha活性。
The presence of two protein-tyrosine phosphatase (PTP) domains is a striking feature in most transmembrane receptor PTPs (RPTPs). The function of the generally inactive membrane-distal PTP domain (RPTP-D2) is unknown. Here we report that an intramolecular interaction between the spacer region (Sp) and the C-terminus in RPTPalpha prohibited intermolecular interactions. Interestingly, stress factors such as H2O2, UV and heat shock induced reversible, free radical-dependent, intermolecular interactions between RPTPalpha and RPTPalpha-SpD2, suggesting an inducible switch in conformation and binding. The catalytic site cysteine of RPTPalpha-SpD2, Cys723, was required for the H2O2 effect on RPTPalpha. H2O2 induced a rapid, reversible, Cys723-dependent conformational change in vivo, as detected by fluorescence resonance energy transfer, with cyan fluorescent protein (CFP) and yellow fluorescent protein (YFP) flanking RPTPalpha-SpD2 in a single chimeric protein. Importantly, H2O2 treatment stabilized RPTPalpha dimers, resulting in inactivation. We propose a model in which oxidative stress induces a conformational change in RPTPalpha-D2, leading to stabilization of RPTPalpha dimers, and thus to inhibition of RPTPalpha activity.