Extracellular regulated kinase (ERK) interaction with actin and the calponin homology (CH) domain of actin-binding proteins.
Extracellular regulated kinase (ERK) interaction with actin and the calponin homology (CH) domain of actin-binding proteins.
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DOI：
10.1042/bj3440117
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发表时间：
1999-11
期刊：
影响因子：
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通讯作者：
B. Leinweber;P. Leavis;P. Leavis;P. Leavis;Z. Grabarek;C.-L. A. Wang;C.-L. A. Wang;Kathleen G. Morgan;Kathleen G. Morgan
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文献类型：
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作者：
B. Leinweber;P. Leavis;P. Leavis;P. Leavis;Z. Grabarek;C.-L. A. Wang;C.-L. A. Wang;Kathleen G. Morgan;Kathleen G. Morgan
细胞外调节激酶1 （ERK1）和钙钙蛋白之间的相互作用先前有报道(Menice, Hulvershorn, Adam， Wang和Morgan (1997) J. Biol。化学，272(40),25157-25161)，并被认为反映了钙钙蛋白作为信号分子的功能。我们在这项研究中报告，钙钙蛋白结合ERK1和ERK2在自然条件下以及在覆盖试验。利用钙钙蛋白的凝乳蛋白酶片段，ERK在钙钙蛋白上的结合位点被鉴定为钙钙蛋白同源结构域（calponin homology， CH），这是其他肌动蛋白结合蛋白中发现的钙钙蛋白的n端区域。在凝胶覆盖试验中，ERK还结合了α -肌动蛋白，一种具有两个串联CH结构域的蛋白质，以及含有α -肌动蛋白CH结构域的α -肌动蛋白的27 kDa热溶酶产物。钙钙蛋白的CH结构域可以与完整的钙钙蛋白或α -肌动蛋白竞争ERK结合。用ERK滴定丙烯丹标记的钙钙蛋白得到的K(a)为6 × 10(6) M(-1)，用ERK alphaL16螺旋的肽滴定丙烯丹标记的钙钙蛋白得到的K(a)为1 × 10(6) M（-1）。发现重组ERK与纯化的肌动蛋白共沉淀，并诱导芘标记的f -肌动蛋白(K(a)=5 × 10（6) M(-1)）的荧光变化。ERK与CH结构域的相互作用指出了CH结构域的一个新的势函数。ERK与肌动蛋白的相互作用提高了肌动蛋白可能为肌肉和非肌肉细胞中的ERK信号复合物提供支架的可能性。
An interaction between extracellular regulated kinase 1 (ERK1) and calponin has previously been reported (Menice, Hulvershorn, Adam, Wang and Morgan (1997) J. Biol. Chem. 272 (40), 25157-25161) and has been suggested to reflect a function of calponin as a signalling molecule. We report in this study that calponin binds to both ERK1 and ERK2 under native conditions as well as in an overlay assay. Using chymotryptic fragments of calponin, the binding site of ERK on calponin was identified as the calponin homology (CH) domain, an N-terminal region of calponin found in other actin-binding proteins. ERK also bound, in a gel overlay assay, alpha-actinin, a protein with two tandem CH domains, as well as a 27 kDa thermolysin product of alpha-actinin containing the CH domains of alpha-actinin. The CH domain of calponin could compete with intact calponin or alpha-actinin for ERK binding. Titration of acrylodan-labelled calponin with ERK gave a K(a) of 6x10(6) M(-1) and titration of acrylodan-labelled calponin with a peptide from the alphaL16 helix of ERK gave a K(a) of 1x10(6) M(-1). Recombinant ERK was found to co-sediment with purified actin and induced a fluorescence change in pyrene-labelled F-actin (K(a)=5x10(6) M(-1)). The interaction of ERK with CH domains points to a new potential function for CH domains. The interaction of ERK with actin raises the possibility that actin may provide a scaffold for ERK signalling complexes in both muscle and non-muscle cells.