MAP kinase activation by hypoosmotic stress of tobacco cell suspensions:: towards the oxidative burst response?
MAP kinase activation by hypoosmotic stress of tobacco cell suspensions:: towards the oxidative burst response?
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DOI：
10.1046/j.1365-313x.1999.00528.x
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发表时间：
1999-08-01
期刊：
影响因子：
7.2
通讯作者：
Laurière, C
中科院分区：
文献类型：
--
作者：
Cazalé, AC;Droillard, MJ;Laurière, C
低渗应激激活磷酸化依赖的氧化爆发。凝胶内激酶测定进行表征的蛋白激酶，可能涉及的调节和激活的氧化爆发。低渗胁迫激活了几种激酶，其中50和46 kDa的蛋白质表现出丝裂原活化蛋白激酶（MAP激酶）的特性。它们在无钙的情况下磷酸化髓鞘碱性蛋白，被针对人MAP激酶的抗体识别，并在酪氨酸上磷酸化。与针对烟草MAP激酶Ntf 4的抗体的免疫沉淀表明，至少有一种活化的激酶将是Ntf 4样的。芹菜素，一种MAP激酶和细胞周期蛋白依赖性激酶抑制剂，其防止低血糖诱导的氧化爆发（Cazale等人，1998; Plant Physiol.116，659-669）在体外抑制这些激酶，表明它们可能在氧化爆发的活化中起作用。与氧化反应一样，激酶的激活依赖于细胞外钙内流和对星形孢菌素和6-DMAP敏感的蛋白激酶。然而，激酶激活并不依赖于流出通过阴离子通道或氧化爆发。二维凝胶内激酶分析显示存在三种蛋白激酶，其表观分子量为50 kDa，一种为46 kDa，所有四种蛋白激酶均被低渗应激激活。同样的激酶也被激活的寡聚半乳糖醛酸和水杨酸，潜在的重要性，这些MAP激酶作为不同的细胞外刺激触发的不同信号通路的共同组成部分。
Hypoosmotic stress activates a phosphorylation-dependent oxidative burst. In-gel kinase assays were performed to characterize the protein kinases that could be implicated in osmoregulation and in the activation of the oxidative burst. Hypoosmotic stress activated several kinases among which 50 and 46kDa proteins displayed mitogen-activated protein kinase (MAP kinase) properties. They phosphorylated myelin basic protein in the absence of calcium, were recognized by antibodies directed against human MAP kinases, and were phosphorylated on tyrosine. Immunoprecipitation with an antibody directed against the tobacco MAP kinase Ntf4 showed that at least one of the activated kinases would be Ntf4-like. Apigenin, a MAP kinase and cyclin-dependent kinase inhibitor which prevents the hypoosmotically induced oxidative burst (Cazale at al., 1998; Plant Physiol. 116, 659-669), inhibited these kinases in vitro suggesting that they may play a role in the activation of the oxidative burst. Like the oxidative response, activation of the kinases depended on extracellular calcium influx and protein kinases sensitive to staurosporine and 6-DMAP. However, kinase activation did not depend on effluxes through anion channels or on the oxidative burst. Two-dimensional in-gel kinase assays revealed the presence of three protein kinases with an apparent molecular mass of 50 kDa and one of 46 kDa, all four being activated by hypoosmotic stress. The same kinases were also activated by oligogalacturonides and salicylic acid, underlying the importance of these MAP kinases as common components of different signaling pathways triggered by different extracellular stimuli.