Redox regulation of Cdc25C
Redox regulation of Cdc25C
复制标题
DOI：
10.1074/jbc.m201589200
复制
发表时间：
2002-06-07
影响因子：
4.8
通讯作者：
Finkel, T
中科院分区：
文献类型：
--
作者：
Savitsky, PA;Finkel, T
Cdc 25家族的双重特异性磷酸酶是细胞周期进程和检查点控制的关键组成部分。某些压力，如紫外线刺激Cdc 25 A蛋白通过Chk 1蛋白激酶依赖性途径的快速和选择性的破坏。我们表明，在以前检查的细胞应力相反，过氧化氢暴露影响Cdc 25 C，但不影响Cdc 25 A水平。Chk 1活性的药理学抑制或缺乏Chk 1磷酸化位点的Cdc 25 C突变体仍然会在氧化剂的作用下发生降解。我们还表明，在体外过氧化氢刺激活性位点半胱氨酸在位置377和另一个不变的半胱氨酸在位置330之间的分子内二硫键。Cdc 25 C的体内稳定性通过这两个半胱氨酸残基中的任一个的突变而显著降低。相比之下，半胱氨酸330和半胱氨酸377的双（C2）突变体导致比野生型Cdc 25 C更稳定的蛋白质，并且对氧化应激诱导的降解具有抗性。此外，C2突变体不能形成分子内二硫键，在体外和体内与14-3-3的结合减少。这些结果表明，氧化应激可能会诱导细胞周期停滞，部分通过降解Cdc 25 C。
The Cdc25 family of dual specific phosphatases are critical components of cell cycle progression and checkpoint control. Certain stresses such as ultraviolet light stimulate the rapid and selective destruction of Cdc25A protein through a Chk1 protein kinase-dependent pathway. We demonstrate that in contrast to cellular stresses previously examined, hydrogen peroxide exposure affects Cdc25C but not Cdc25A levels. Pharmacological inhibition of Chk1 activity or a mutant of Cdc25C that lacks the Chk1 phosphorylation site still undergoes degradation in response to oxidants. We also demonstrate that in vitro hydrogen peroxide stimulates an intramolecular disulfide bond between the active site cysteine at position 377 and another invariant cysteine at position 330. The in vivo stability of Cdc25C is substantially reduced by the mutation of either of these two cysteine residues. In contrast, a double (C2) mutant of both cysteine 330 and cysteine 377 results in a protein that is more stable than wild type Cdc25C and is resistant to oxidative stress-induced degradation. In addition, the C2 mutant, which is unable to form an intramolecular disulfide bond, has reduced binding to 14-3-3 in vitro and in vivo. These results suggest that oxidative stress may induce cell cycle arrest in part through the degradation of Cdc25C.