Association of CPI-17 with protein kinase C and casein kinase I
Association of CPI-17 with protein kinase C and casein kinase I
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DOI：
10.1016/j.bbrc.2004.02.014
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发表时间：
2004-03-26
影响因子：
3.1
通讯作者：
Dubois, T
中科院分区：
文献类型：
--
作者：
Zemlickova, E;Johannes, FJ;Dubois, T
17 kDa的蛋白激酶C增强抑制剂蛋白，称为CPI-17，特异性抑制肌球蛋白轻链磷酸酶（MLCP）。Thr-38在体内的磷酸化高度增强CPI-17抑制MLCP的能力。Thr-38在体外被许多蛋白激酶磷酸化，包括蛋白激酶C（PKC）、Rho相关卷曲螺旋激酶（ROCK）和蛋白激酶N（PKN）。在这项研究中，我们重点关注蛋白激酶与CPI-17的关联。使用亲和层析和Western印迹分析，我们发现与所有的PKC亚型和酪蛋白激酶I亚型，CKIalpha和Me. By相比，ROCK和PKN没有与CPI-17，这表明PKC可能是相关的激酶，磷酸化Thr-38在体内的相互作用。CPI-17与PKC的富含半胱氨酸的结构域相互作用，并被所有PKC同种型磷酸化。我们以前发现CPI-17与脑中的酪蛋白激酶I共纯化，表明它们是复合物的一部分，我们现在表明CPI-17与CKI同种型的激酶结构域相关。(C)2004爱思唯尔公司All rights reserved.
The protein kinase C-potentiated inhibitor protein of 17 kDa, called CPI-17, specifically inhibits myosin light chain phosphatase (MLCP). Phosphorylation of Thr-38 in vivo highly potentiates the ability of CPI-17 to inhibit MLCP. Thr-38 has been shown to be phosphorylated in vitro by a number of protein kinases including protein kinase C (PKC), Rho-associated coiled-coil kinase (ROCK), and protein kinase N (PKN). In this study we have focused on the association of protein kinases with CPI-17. Using affinity chromatography and Western blot analysis, we found interaction with all PKC isotypes and casein kinase I isoforms, CKIalpha and Me. By contrast, ROCK and PKN did not associate with CPI-17, suggesting that PKC may be the relevant kinase that phosphorylates Thr-38 in vivo. CPI-17 interacted with the cysteine-rich domain of PKC and was phosphorylated by all PKC isotypes. We previously found that CPI-17 co-purified with casein kinase I in brain suggesting they are part of a complex and we now show that CPI-17 associates with the kinase domain of CKI isoforms. (C) 2004 Elsevier Inc. All rights reserved.