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AMPK复合物在非活性且ATP结合状态下的结构获解析
作者:小柯机器人 发布时间:2021/7/25 14:54:00

2021年7月23日,美国Van Andel研究所Karsten Melcher课题组在《科学》杂志在线发表论文,揭示AMPK复合物在非活性且ATP结合状态下的结构。

研究人员表示,单磷酸腺苷(AMP)激活的蛋白激酶(AMPK)根据细胞能量状态调节新陈代谢。在能量压力下,AMP稳定活跃的AMPK构象,其中激酶激活环(AL)受到蛋白磷酸酶的保护,从而使AL处于活跃、磷酸化的状态。在低的AMP:ATP(三磷酸腺苷)比率下,ATP通过增加AL的动态和可及性来抑制AMPK。

研究人员开发了构象特异性抗体来捕获ATP结合的AMPK,使其处于完全非活性的动态状态,并使用冷冻电镜以3.5埃的分辨率确定了其结构。对激酶结构域进行180°旋转和100埃位移,使AL完全暴露。在该结构和支持性生物物理数据的基础上,研究人员提出了一个多步骤的机制,解释了腺嘌呤核苷酸和药物激动剂如何通过改变AL的磷酸化和可及性来调节AMPK的活性。

附:英文原文

Title: Structure of an AMPK complex in an inactive, ATP-bound state

Author: Yan Yan, Somnath Mukherjee, Kaleeckal G. Harikumar, Timothy S. Strutzenberg, X. Edward Zhou, Kelly Suino-Powell, Ting-Hai Xu, Ryan D. Sheldon, Jared Lamp, Joseph S. Brunzelle, Katarzyna Radziwon, Abigail Ellis, Scott J. Novick, Irving E. Vega, Russell G. Jones, Laurence J. Miller, H. Eric Xu, Patrick R. Griffin, Anthony A. Kossiakoff, Karsten Melcher

Issue&Volume: 2021/07/23

Abstract: Adenosine monophosphate (AMP)–activated protein kinase (AMPK) regulates metabolism in response to the cellular energy states. Under energy stress, AMP stabilizes the active AMPK conformation, in which the kinase activation loop (AL) is protected from protein phosphatases, thus keeping the AL in its active, phosphorylated state. At low AMP:ATP (adenosine triphosphate) ratios, ATP inhibits AMPK by increasing AL dynamics and accessibility. We developed conformation-specific antibodies to trap ATP-bound AMPK in a fully inactive, dynamic state and determined its structure at 3.5-angstrom resolution using cryo–electron microscopy. A 180° rotation and 100-angstrom displacement of the kinase domain fully exposes the AL. On the basis of the structure and supporting biophysical data, we propose a multistep mechanism explaining how adenine nucleotides and pharmacological agonists modulate AMPK activity by altering AL phosphorylation and accessibility.

DOI: 10.1126/science.abe7565

Source: https://science.sciencemag.org/content/373/6553/413

 

期刊信息
Science:《科学》,创刊于1880年。隶属于美国科学促进会,最新IF:41.037