Nakashima Izumi, Kawamoto Yoshiyuki, Takeda Kozue, Kato Masashi
Department of Biomedical Sciences, College of Life and Health Sciences, Chubu University, Kasugai, Aichi 487-8501, Japan.
Enzyme Res. 2011;2011:896567. doi: 10.4061/2011/896567. Epub 2011 Jun 26.
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.
近期有关环境对基因规定的细胞激活或细胞死亡信号系统的调控的观察结果已得到综述，重点关注蛋白酪氨酸激酶（PTK）活性的调节。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，并在细胞中诱导活性氧（ROS）的产生。如此产生的ROS可能通过使使自磷酸化的PTK去磷酸化并使其失活的蛋白酪氨酸磷酸酶失活，从而上调PTK的催化活性。然而，最近的证据表明，ROS也可以直接氧化PTK上基因保守的特定半胱氨酸的SH基团，有时会产生PTK蛋白的二硫键连接的二聚体，以上调或下调其催化活性。本文讨论了氧化还原反应/共价键介导的蛋白质三级结构连接的非共价键导向信号系统修饰在生物体中的基本作用。
