Spatiotemporal regulation of ERK2 by dual specificity phosphatases.
Spatiotemporal regulation of ERK2 by dual specificity phosphatases.
复制标题
双重特异性磷酸酶对ERK2的时空调节。
DOI：
10.1074/jbc.m801500200
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发表时间：
2008-09-26
影响因子：
4.8
通讯作者：
McArdle, Craig A.
中科院分区：
文献类型：
--
作者：
Caunt, Christopher J.;Armstrong, Stephen P.;Rivers, Caroline A.;Norman, Michael R.;McArdle, Craig A.
尽管许多刺激激活细胞外信号调节激酶1和2 (ERK1/2)，但ERK1/2信号的动力学和区隔化是刺激依赖性的，并决定了生理后果。双特异性磷酸酶（DUSPs）可以使ERKs失活，特别是MAPK磷酸酶（MKPs）和非典型DUSPs，它们既可以使ERK1/2去磷酸化，也可以支架ERK1/2。利用细胞成像模型（基于内源性ERKs的敲除和野生型或突变的ERK2- gfp报告基因的加回），我们探索了DUSPs对瞬时或持续ERK2激活因子（分别为表皮生长因子和phorbol 12,13-二丁酸酯）反应的可能影响。对于这两种刺激，D319N突变（损害DUSP结合）增加ERK2活性并减少核积累。这些刺激也增加了8个dusp的mRNA水平。在短期抑制RNA筛选中，16个DUSPs中有12个影响ERK2反应。这些影响在核诱导型MKP、细胞质ERK MKP、JNK/p38 MKP和非典型DUSP亚型中都很明显，除核诱导型MKP外，与Egr-1荧光素酶激活的相应变化相似。同时去除所有JNK/p38 MKPs或核诱导型MKPs表明它们分别是ERK2信号的正调控因子和负调控因子。JNK/p38 MKP短抑制rna的作用不依赖于蛋白质新合成，但在JNK和p38激酶抑制剂存在时被逆转，这表明dusp介导的MAPK通路之间的串扰。总的来说，我们的数据显示大量dusp影响ERK2信号传导。结合已知的DUSPs的组织特异性表达和ERK1/2在细胞调节中的重要性，我们的数据支持DUSPs作为药物治疗靶点的潜在价值。
Although many stimuli activate extracellular signal-regulated kinases 1 and 2 (ERK1/2), the kinetics and compartmentalization of ERK1/2 signals are stimulus-dependent and dictate physiological consequences. ERKs can be inactivated by dual specificity phosphatases (DUSPs), notably the MAPK phosphatases (MKPs) and atypical DUSPs, that can both dephosphorylate and scaffold ERK1/2. Using a cell imaging model (based on knockdown of endogenous ERKs and add-back of wild-type or mutated ERK2-GFP reporters), we explored possible effects of DUSPs on responses to transient or sustained ERK2 activators (epidermal growth factor and phorbol 12,13-dibutyrate, respectively). For both stimuli, a D319N mutation (which impairs DUSP binding) increased ERK2 activity and reduced nuclear accumulation. These stimuli also increased mRNA levels for eight DUSPs. In a short inhibitory RNA screen, 12 of 16 DUSPs influenced ERK2 responses. These effects were evident among nuclear inducible MKP, cytoplasmic ERK MKP, JNK/p38 MKP, and atypical DUSP subtypes and, with the exception of the nuclear inducible MKPs, were paralleled by corresponding changes in Egr-1 luciferase activation. Simultaneous removal of all JNK/p38 MKPs or nuclear inducible MKPs revealed them as positive and negative regulators of ERK2 signaling, respectively. The effects of JNK/p38 MKP short inhibitory RNAs were not dependent on protein neosynthesis but were reversed in the presence of JNK and p38 kinase inhibitors, indicating DUSP-mediated cross-talk between MAPK pathways. Overall, our data reveal that a large number of DUSPs influence ERK2 signaling. Together with the known tissue-specific expression of DUSPs and the importance of ERK1/2 in cell regulation, our data support the potential value of DUSPs as targets for drug therapy.