Control of genetically prescribed protein tyrosine kinase activities by environment-linked redox reactions.
Control of genetically prescribed protein tyrosine kinase activities by environment-linked redox reactions.
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作者：
Nakashima I;Kawamoto Y;Takeda K;Kato M
本文综述了近年来有关环境调控基因调控细胞活化或死亡信号系统的研究进展，重点介绍了蛋白酪氨酸激酶（PTKs）活性的调控。与环境相关的氧化还原反应似乎主要影响细胞表面受体和细胞膜脂筏，并诱导细胞内活性氧（ROS）的产生。由此产生的ROS可能通过使蛋白酪氨酸磷酸酶失活而上调PTKs的催化活性，所述蛋白酪氨酸磷酸酶使PTKs脱磷酸化并使自磷酸化的PTKs活化。然而，最近的证据表明，ROS也可以直接氧化PTK上遗传保守的特定半胱氨酸的SH基团，有时产生PTK蛋白的二硫键键二聚体，用于上调或下调其催化活性。氧化还原反应/共价键介导的蛋白质三级结构连接的非共价键导向的信号系统在生物体中的基本作用进行了讨论。
Recent observations on environment-linked control of genetically prescribed signaling systems for either cell activation or cell death have been reviewed with a focus on the regulation of activities of protein tyrosine kinases (PTKs). The environment-linked redox reactions seem to primarily affect cell surface receptors and cell membrane lipid rafts, and they induce generation of reactive oxygen species (ROS) in cells. ROS thus generated might upregulate the catalytic activities of PTKs through inactivating protein tyrosine phosphatases that dephosphorylate and inactivate autophosphorylated PTKs. Recent evidence has, however, demonstrated that ROS could also directly oxidize SH groups of genetically conserved specific cysteines on PTKs, sometimes producing disulfide-bonded dimers of PTK proteins, either for upregulation or downregulation of their catalytic activities. The basic role of the redox reaction/covalent bond-mediated modification of protein tertiary structure-linked noncovalent bond-oriented signaling systems in living organisms is discussed.