Dynamics of functional membrane complexes associated with the plasma membrane H+-ATPase AHA2

质膜是细胞质与外界环境之间物质(养分、激素)交换的边界隔间。植物必须迅速调整它们的细胞状态、生长发育和新陈代谢以适应环境的变化。近年来，细胞质膜的蛋白质组成具有高度的动态性和刺激性。在植物质膜中，H+-ATPase是含量最丰富的蛋白质。H+-ATPase不仅对跨膜溶质运输是必不可少的，而且还可以影响细胞的伸长、气孔的打开和关闭以及对环境胁迫和病原体攻击的反应。因此，H+-ATPase受到高度的调节，特别是通过不同的激酶在几个激活和抑制位置的磷酸化来调节。最近在质膜中发现了短的、直接的调节途径，涉及到受体激酶调节质子泵、水通道和其他膜转运蛋白，这表明这是一种模块化的通用原理，使植物能够非常迅速地适应不断变化和具有挑战性的环境。我们认为，依赖于外界条件，与H+-ATPase相互作用的受体/辅助受体对是一个动态复合体的可变组成部分，导致H+-ATPase在激活或抑制磷酸化位点时发生条件性相互作用和磷酸化。基于所提出的质膜内动态功能蛋白质复合体模型，我们旨在利用蛋白质组学和现代光镜方法系统地研究质膜H+-ATPase AHA2如何在外部刺激下形成不同的蛋白质复合体。因此，我们对动态招募到AHA2的这些功能复合体中的受体激酶/辅助受体对特别感兴趣

The plasma membrane is the boundary compartment which enables exchange of substances (nutrients, hormones) between cytosol and the outside environment. Plants must rapidly adjust their cellular status, growth and development and metabolism to changes in the environment. In recent years it became more and more evident that the protein composition of the plasma membrane is highly dynamic and stimulus-dependent. Within the plasma membrane of plants, the H+-ATPases are the most abundant proteins. The H+-ATPases are not only essential for transmembrane solute transport, but can also affect cell elongation, the opening and closing of the stomata and the responses to environmental stress and pathogen attack. Thus, the H+-ATPases are highly regulated, particularly by phosphorylation at several activating and inhibiting sites by different kinases. The recent discovery of short, direct regulatory pathways within the plasma membrane involving receptor kinases regulating proton pumps, water channels and other membrane transporters suggests that this is a modular generic principle allowing plants to very rapidly adjust to changing and challenging environments. We propose that dependent on external conditions, the receptor/coreceptor pairs interacting with the H+-ATPase are variable components of a dynamic complex resulting in conditional interactions and phosphorylation of the H+-ATPase at activating or inhibiting phosphorylation sites.Based on the proposed model of dynamic functional protein complexes within the plasma membrane, we aim at systematically studying how the plasma membrane H+-ATPase AHA2 forms different protein complexes dependent on external stimuli using a combination of proteomics and modern spectro-microscopic methods. Thereby, we are particularly interested in the receptor kinase / co-receptor pairs dynamically recruited into these functional complexes of AHA2