Post-translationale Regulation pflanzlicher schwach gleichrichtender K+ Kanäle

植物弱整流钾离子通道的翻译后调控

• 批准号: 225519582
• 负责人: Professor Dr. Ingo Dreyer
• 金额: --
• 依托单位: Centro de Bioinformatica y Simulacion Molecular
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2012
• 资助国家: 德国
• 起止时间: 2011-12-31 至 2015-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/225519582?language=en
• 关键词: Post; translationale; Regulation; pflanzlicher; schwach

Weakly rectifying K+ (Kweak) channels are unique among potassium channels in plants. These voltage-gated K+ channel have exceptional gating properties that are strongly regulated by a complex spectrum of posttranslational modifications. These channels can act in two different modes. In modus 1 they behave as inward-rectifying potassium channels mediating K+ uptake only. In modus 2, however, they are locked open and can therefore transport K+ in both directions over the plasmamembrane. In a recent study, the group of the PI could clarify the physiological significance of this regulation. Post-translational modification of Kweak channels taps a ‘potassium battery’ that then efficiently assists the plasma membrane H+-ATPase in energizing transmembrane transport processes in phloem tissues. Unfortunately, up to now, knowledge on the signaling cascades that regulate activity and operation mode of Kweak channels is still very limited. The project proposed here aims at investigating further steps in these signaling cascades by identifying proteins that interact with the Kweak channel AKT2 from the model plant Arabidopsis thaliana and regulate its activity. Interacting proteins will be identified using improved versions of the yeast-two hybrid system and the split-ubiquitin system, in direct proteomic approaches as well as by in silico methods. The regulatory function of the newly identified proteins will be tested directly in co-expression experiments and analyses of AKT2 activity. The newly gathered information will provide the basis for developing a Kweak-regulatory network. The dynamics of this network will be investigated in computational simulations. Beneficial aspects of AKT2-channel regulation that were uncovered in Arabidopsis will be tested also in poplar.

弱整流钾通道是植物钾离子通道中的一种特殊通道。这些电压门控K+通道具有特殊的门控特性，受到复杂的翻译后修饰谱的强烈调控。这些通道可以以两种不同的模式起作用。在模式1中，它们表现为仅介导K+吸收的内向整流钾通道。然而，在模式2中，它们被锁定打开，因此可以在质膜上双向运输K+。在最近的一项研究中，PI小组可以阐明这种调节的生理意义。Kweak通道的翻译后修饰利用“钾电池”，然后有效地帮助质膜H+-ATP酶在韧皮部组织中激发跨膜运输过程。遗憾的是，到目前为止，对调节Kweak通道活性和运作模式的信号级联的了解仍然非常有限。这里提出的项目旨在通过鉴定与来自模式植物拟南芥的Kweak通道AKT 2相互作用并调节其活性的蛋白质来研究这些信号级联中的进一步步骤。相互作用的蛋白质将被确定使用酵母双杂交系统和分裂泛素系统的改进版本，在直接蛋白质组学方法，以及通过计算机方法。新鉴定的蛋白质的调节功能将在共表达实验和AKT 2活性分析中直接测试。新收集的信息将为建立Kweak监管网络提供基础。这个网络的动力学将在计算模拟中进行研究。在拟南芥中发现的AKT 2通道调节的有益方面也将在白杨中进行测试。