cGMP-binding prepares PKG for substrate binding by disclosing the C-terminal domain
cGMP-binding prepares PKG for substrate binding by disclosing the C-terminal domain
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DOI：
10.1016/j.jmb.2007.11.053
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发表时间：
2008-02-01
影响因子：
5.6
通讯作者：
Heck, Albert J. R.
中科院分区：
文献类型：
--
作者：
Alverdi, Vera;Mazon, Hortense;Heck, Albert J. R.
I型环鸟苷3 '，5'-单磷酸（cGMP）依赖性蛋白激酶（PKG）参与一氧化氮/cGMP信号通路。PKG已在许多不同物种中被鉴定，范围从单细胞生物到哺乳动物。这种酶作为细胞内cGMP的主要受体蛋白之一，控制各种细胞反应，从平滑肌松弛到神经元突触可塑性。在没有晶体结构的情况下，同源二聚体152 kDa激酶PKG的三维结构是未知的;然而，有证据表明，与非活性构象相比，激酶采用了不同的cGMP依赖性活性构象。我们进行了基于质谱的氢/氘交换实验，以获得关于cGMP活化诱导的PKG Ia结构变化的详细信息。位点特异性交换测量证实，自抑制结构域和铰链区变得更加溶剂暴露，而cGMP结合结构域变得更加保护holo-PKG（二聚体PKG饱和与四个cGMP分子结合）。更令人惊讶的是，我们的数据揭示了一个具体的披露的底物结合区域的holo-PKG，脱落到PKG的激酶激活过程的新的光。(C)2007爱思唯尔有限公司保留所有权利。
Type I cyclic guanosine 3',5'-monophosphate (cGMP)-dependent protein kinase (PKG) is involved in the nitric oxide/cGMP signaling pathway. PKG has been identified in many different species, ranging from unicelolular organisms to mammals. The enzyme serves as one of the major receptor proteins for intracellular cGMP and controls a variety of cellular responses, ranging from smooth-muscle relaxation to neuronal synaptic plasticity. In the absence of a crystal structure, the three-dimensional structure of the homodimeric 152-kDa kinase PKG is unknown; however, there is evidence that the kinase adopts a distinct cGMP-dependent active conformation when compared to the inactive conformation. We performed mass-spectrometry-based hydrogen/deuterium exchange experiments to obtain detailed information on the structural changes in PKG la induced by cGMP activation. Site-specific exchange measurements confirmed that the autoinhibitory domain and the hinge region become more solvent exposed, whereas the cGMP-binding domains become more protected in holo-PKG (dimeric PKG saturated with four cGMP molecules bound). More surprisingly, our data revealed a specific disclosure of the substrate-binding region of holo-PKG, shedding new light into the kinase-activation process of PKG. (C) 2007 Elsevier Ltd. All rights reserved.