在植物王国中广泛存在的谷氨胺感应机制
Vasuki-Ranjani Chellamuthu1, Elena Ermilova2, Tatjana Lapina2
1Interfaculty Institute for Microbiology and Infection Medicine, University of Tübingen, Auf der Morgenstelle 28, 72076 Tübingen, Germany; Department of Protein Evolution, Max Planck Institute for Developmental Biology, Spemannstrasse 35, 72076 Tübingen, Germany.
Cell
|November 24, 2014
概括
植物拥有一个保留的谷氨酸感应机制,涉及PII蛋白及其Q循环. 这个系统通过控制N-乙-l-酸盐激酶 (NAGK) 活动来调节同化,这对生长至关重要.
科学领域:
- 植物生理学 植物生理学
- 分子生物学分子生物学
- 生物化学 生物化学
背景情况:
- 谷氨酸是植物中的同化过程中的核心成分.
- 监测细胞状况对于代谢平衡和生长至关重要.
- 在整个植物王国中发现了一种保存的谷氨胺感应机制,不包括Brassicaceae.
研究的目的:
- 为了识别和描述植物中的谷氨胺感应机制.
- 阐明PII信号蛋白在代谢中的作用.
- 了解谷氨胺结合的结构基础及其对酶活性的影响.
主要方法:
- 使用X射线晶体学进行结构分析,以确定PII蛋白质构成.
- 生物化学测试以评估PII-NAGK相互作用和酶动力学.
- 对PII蛋白进行基因操纵,以测试功能性保存.
主要成果:
- PII蛋白的C端延伸,Q循环,作为一种低亲和度的谷氨胺结合部位.
- 氨酸结合会诱导PII的形状变化,激活N-乙-l-氨酸激酶 (NAGK).
- 这种机制在大多数植物中是保留的,但在 Brassicaceae 中不存在.
结论:
- PII-Q循环系统提供了一个模块化机制,用于植物叶绿体中的谷氨胺传感.
- 这一途径通过NAGK调节阿尔金因和聚胺的合成.
- 布拉西卡系植物中这种机制的缺失表明,在探测方面存在进化分歧.
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