Reversible S-glutathionylation of Cys374 regulates actin filament formation by inducing structural changes in the actin molecule
Reversible S-glutathionylation of Cys374 regulates actin filament formation by inducing structural changes in the actin molecule
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DOI：
10.1016/s0891-5849(02)01182-6
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发表时间：
2003-01-01
影响因子：
7.4
通讯作者：
Milzani, A
中科院分区：
文献类型：
--
作者：
Dalle-Donne, I;Giustarini, D;Milzani, A
S-谷胱甘肽化是目标蛋白中半胱氨酰残基与谷胱甘肽混合二硫化物的可逆形成，发生在氧化应激条件下；这可能是一种翻译后机制，通过该机制蛋白质功能受到细胞氧化还原状态的调节。最近提出了由 Cys(374) 谷胱甘肽化调节的肌动蛋白聚合的新生理相关性。在本研究中，我们表明，与天然肌动蛋白相比，谷胱甘肽肌动蛋白（GS-肌动蛋白）的聚合能力降低，丝伸长实际上是聚合步骤受到抑制。肌动蛋白聚合性在脱硫后完全恢复，表明S-谷胱甘肽化不会诱导任何蛋白质变性，因此是一种可逆的氧化修饰。 S-谷胱甘肽化后观察到的蛋白质表面疏水区域暴露增加表明肌动蛋白构象发生变化。肌动蛋白亚结构域 2 的 DNase-I 结合环中 ATP 交换速率的增加以及 Met(47) 和 Gly(48) 之间的枯草杆菌蛋白酶切割位点对蛋白水解的敏感性降低证实了结构改变。S-谷胱甘肽化诱导的表面环 39-51 的结构变化可能会影响肌动蛋白聚合，因为涉及肌动蛋白的 N 末端部分。正如 F-肌动蛋白原子模型所预测的那样，单体间相互作用中存在这种循环。 (C) 2002 爱思唯尔科学公司。
S-glutathionylation, the reversible formation of mixed disulphides of cysteinyl residues in target proteins with glutathione, occurs under conditions of oxidative stress; this could be a posttranslational mechanism through which protein function is regulated by the cellular redox status. A novel physiological relevance of actin polymerization regulated by glutathionylation Of Cys(374) has been recently suggested. In the present study we showed that glutathionylated actin (GS-actin) has a decreased capacity to polymerize compared to native actin, filament elongation being the polymerization step actually inhibited. Actin polymerizability recovers completely after dethiolation, indicating that S-glutathionylation does not induce any protein denaturation and is therefore a reversible oxidative modification. The increased exposure of hydrophobic regions of protein surface observed upon S-glutathionylation indicates changes in actin conformation. Structural alterations are confirmed by the increased rate of ATP exchange as well as by the decreased susceptibility to proteolysis of the subtilisin cleavage site between Met(47) and Gly(48), in the DNase-I-binding loop of the actin subdomain 2. Structural changes in the surface loop 39-51 induced by S-glutathionylation could influence actin polymerization in view of the involvement of the N-terminal portion of this loop in intermonomer interactions, as predicted by the atomic models of F-actin. (C) 2002 Elsevier Science Inc.