肌动蛋白ATP酶家族的聚合调节酵母己糖激酶活性

作者：杨超月

本期文章：《科学》：Volume 367 Issue 6481

美国哈佛大学Ethan C. Garner、Andrew W. Murray等研究人员合作发现，肌动蛋白ATP酶家族的聚合调节酵母己糖激酶活性。2020年2月28日，《科学》发表了这一成果。

研究人员发现，一种酿酒酵母葡萄糖激酶（Glk1）能够形成具有超微结构的二链丝，该结构不同于细胞骨架聚合物。在细胞中，添加糖后Glk1聚合，而撤糖时解聚。聚合抑制酶活性；Glk1单体与聚合物的平衡设定了最大的葡萄糖磷酸化速率，而与Glk1的浓度无关。消除Glk1聚合的突变减轻了浓度依赖性酶抑制作用。

含非聚合性Glk1的酵母在糖上生长时适应性更低，而在重新给葡萄糖时更容易死亡。Glk1聚合独立于其他肌动蛋白相关的细丝，并可能随着营养物利用率的变化而使酵母迅速调节葡萄糖激酶活性。

据介绍，肌动蛋白折叠存在于细胞骨架聚合物、分子伴侣和各种代谢酶中。许多肌动蛋白折叠蛋白（例如碳水化合物激酶）不会聚合。

附：英文原文

Title: Polymerization in the actin ATPase clan regulates hexokinase activity in yeast

Author: Patrick R. Stoddard, Eric M. Lynch, Daniel P. Farrell, Annie M. Dosey, Frank DiMaio, Tom A. Williams, Justin M. Kollman, Andrew W. Murray, Ethan C. Garner

Issue&Volume: 2020/02/28

Abstract: AbstractThe actin fold is found in cytoskeletal polymers, chaperones, and various metabolic enzymes. Many actin-fold proteins, such as the carbohydrate kinases, do not polymerize. We found that Glk1, a Saccharomyces cerevisiae glucokinase, forms two-stranded filaments with ultrastructure that is distinct from that of cytoskeletal polymers. In cells, Glk1 polymerized upon sugar addition and depolymerized upon sugar withdrawal. Polymerization inhibits enzymatic activity; the Glk1 monomer-polymer equilibrium sets a maximum rate of glucose phosphorylation regardless of Glk1 concentration. A mutation that eliminated Glk1 polymerization alleviated concentration-dependent enzyme inhibition. Yeast containing nonpolymerizing Glk1 were less fit when growing on sugars and more likely to die when refed glucose. Glk1 polymerization arose independently from other actin-related filaments and may allow yeast to rapidly modulate glucokinase activity as nutrient availability changes.

DOI: 10.1126/science.aay5359

Source: https://science.sciencemag.org/content/367/6481/1039

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

官方网址：https://www.sciencemag.org/