Regulation of the plasma membrane proton pump (H(+)-ATPase) by phosphorylation.
Regulation of the plasma membrane proton pump (H(+)-ATPase) by phosphorylation.
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DOI：
10.1016/j.pbi.2015.09.005
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发表时间：
2015-12
影响因子：
9.5
通讯作者：
Sussman MR
中科院分区：
文献类型：
--
作者：
Haruta M;Gray WM;Sussman MR
在植物和真菌中，质膜上的能量是由专门用于质子运输的P型ATP酶家族（通常称为PM H+-ATP酶，或者在拟南芥中称为拟南芥H+-ATP酶的AHA）产生的大质子动力（PMF）提供的。研究表明，这种100 kDa的蛋白质是植物生长和发育所必需的。H+-ATP酶的翻译后修饰在其调节中起着关键作用。由~ 100个氨基酸组成的羧基末端调节结构域内的几个Thr和Ser残基的磷酸化响应于环境刺激、内源性激素和营养条件而改变。最近开发的质谱技术提供了一种手段，仔细量化这些变化的H+-ATP酶磷酸化在不同的网站。这些化学修饰然后可以在植物中通过用磷酸化模拟突变补充功能丧失的aha突变体来进行遗传测试。有趣的是，最近的数据表明，磷酸酶介导的PM H+-ATP酶磷酸化的变化是重要的，在介导生长素调节的生长。因此，与另一种激素（脱落酸），磷酸酶，而不是激酶介导的磷酸化，去磷酸化，可能是一个重要的焦点调节植物信号转导过程中。虽然与其他蛋白质的相互作用也涉及ATP酶的调节，非常疏水性和高浓度的这种多位蛋白提出了特殊的挑战，在评估这些相互作用的生物学意义。只有通过结合生物化学和遗传学实验，我们才能尝试应对这些挑战，以了解这种蛋白质在植物中发挥作用的基本分子细节。
In plants and fungi, energetics at the plasma membrane is provided by a large protonmotive force (PMF) generated by the family of P-type ATPases specialized for proton transport (commonly called PM H+-ATPases or, in Arabidopsis, AHAs for Arabidopsis H+-ATPases). Studies have demonstrated that this 100-kDa protein is essential for plant growth and development. Posttranslational modifications of the H+-ATPase play critical roles in its regulation. Phosphorylation of several Thr and Ser residues within the carboxy terminal regulatory domain composed of ~ 100 amino acids change in response to environmental stimuli, endogenous hormones, and nutrient conditions. Recently developed mass spectrometric technologies provide a means to carefully quantify these changes in H+-ATPase phosphorylation at the different sites. These chemical modifications can then be genetically tested in planta by complementing the loss-of-function aha mutants with phosphomimetic mutations. Interestingly, recent data suggest that phosphatase-mediated changes in PM H+-ATPase phosphorylation are important in mediating auxin-regulated growth. Thus, as with another hormone (abscisic acid), dephosphorylation by phosphatases, rather than kinase mediated phosphorylation, may be an important focal point for regulation during plant signal transduction. Although interactions with other proteins have also been implicated in ATPase regulation, the very hydrophobic nature and high concentration of this polytopic protein presents special challenges in evaluating the biological significance of these interactions. Only by combining biochemical and genetic experiments can we attempt to meet these challenges to understand the essential molecular details by which this protein functions in planta.