Twomey Edward C, Cordasco Dana F, Wei Yufeng
Department of Chemistry and Biochemistry, Seton Hall University, South Orange, NJ 07079, USA.
Biochim Biophys Acta. 2012 Dec;1824(12):1382-93. doi: 10.1016/j.bbapap.2012.07.001. Epub 2012 Jul 20.
PED/PEA-15 is a small, non-catalytic, DED containing protein that is widely expressed in different tissues and highly conserved among mammals. PED/PEA-15 has been found to interact with several protein targets in various pathways, including FADD and procaspase-8 (apoptosis), ERK1/2 (cell cycle entry), and PLD1/2 (diabetes). In this research, we have studied the PED/PEA-15 in a complex with ERK2, a MAP kinase, using NMR spectroscopic techniques. MAP Kinase signaling pathways are involved in the regulation of many cellular functions, including cell proliferation, differentiation, apoptosis and survival. ERK1/2 are activated by a variety of external stimuli, including growth factors, hormones and neurotransmitters. Inactivated ERK2 is primarily found in the cytosol. Once the ERK/MAPK cascade is initiated, ERK2 is phosphorylated and stimulated, allowing it to redistribute in the cell nucleus and act as a transcription factor. Previous studies have shown that PED/PEA-15 complexes with ERK2 in the cytoplasm and prevents redistribution into the nucleus. Although the NMR structure and dynamics of PED/PEA-15 in the free form have been documented recently, no detailed structural and dynamic information for the ERK2-bound form is available. Here we report NMR chemical shift perturbation and backbone dynamic studies at the fast ps-ns timescale of PED/PEA-15, in its free form and in the complex with ERK2. These analyses characterize motions and conformational changes involved in ERK2 recognition and binding that orchestrate the reorganization of the DED and immobilization of the C-terminal tail. A new induced fit binding model for PED/PEA-15 is proposed.
PED/PEA - 15是一种小型的、无催化活性的、含死亡效应结构域（DED）的蛋白质，在不同组织中广泛表达，在哺乳动物中高度保守。PED/PEA - 15已被发现在多种信号通路中与多个蛋白质靶点相互作用，包括FADD和procaspase - 8（凋亡）、ERK1/2（细胞周期进入）以及PLD1/2（糖尿病相关）。在本研究中，我们使用核磁共振光谱技术研究了与丝裂原活化蛋白激酶（MAP激酶）ERK2形成复合物的PED/PEA - 15。MAP激酶信号通路参与多种细胞功能的调节，包括细胞增殖、分化、凋亡和存活。ERK1/2可被多种外部刺激激活，包括生长因子、激素和神经递质。未活化的ERK2主要存在于细胞质中。一旦ERK/MAPK级联反应启动，ERK2就会被磷酸化并激活，使其能够重新分布到细胞核中并作为转录因子发挥作用。先前的研究表明，PED/PEA - 15在细胞质中与ERK2形成复合物，并阻止其重新分布到细胞核中。尽管最近已经报道了游离形式的PED/PEA - 15的核磁共振结构和动力学，但关于与ERK2结合形式的详细结构和动力学信息尚无报道。在此，我们报告了PED/PEA - 15游离形式及其与ERK2复合物在快速皮秒 - 纳秒时间尺度下的核磁共振化学位移扰动和主链动力学研究。这些分析表征了ERK2识别和结合过程中涉及的运动和构象变化，这些变化协调了DED的重组和C末端尾巴的固定。我们提出了一种新的PED/PEA - 15诱导契合结合模型。
