Kinoshita Satoru N, Kinoshita Toshinori
Graduate School of Science, Nagoya University, Nagoya, Japan.
Institute of Transformative Bio-Molecules (WPI-ITbM), Nagoya University, Nagoya, Japan.
Front Plant Sci. 2022 Aug 12;13:982485. doi: 10.3389/fpls.2022.982485. eCollection 2022.
In plants, cytosolic and extracellular pH homeostasis are crucial for various physiological processes, including the uptake of macronutrients and micronutrients, cell elongation, cell expansion, and enzyme activity. Proton (H) gradients and the membrane potential are generated by a H pump consisting of an active primary transporter. Plasma membrane (PM) H-ATPase, a PM-localized H pump, plays a pivotal role in maintaining pH homeostasis in plant cells and extracellular regions. PM H-ATPase activity is regulated by protein abundance and by post-translational modifications. Several stimuli have been found to activate the PM H-ATPase through phosphorylation of the penultimate threonine (Thr) of the carboxy terminus. Light- and photosynthesis-induced phosphorylation of PM H-ATPase are conserved phenomena among various plant species. In this work, we review recent findings related to PM H-ATPase regulation in the photosynthetic tissues of plants, focusing on its mechanisms and physiological roles. The physiological roles of photosynthesis-dependent PM H-ATPase activation are discussed in the context of nitrate uptake and cytoplasmic streaming in leaves.
在植物中，胞质和细胞外的pH稳态对于各种生理过程至关重要，包括大量营养素和微量营养素的吸收、细胞伸长、细胞扩张以及酶活性。质子（H）梯度和膜电位由一个由活性初级转运体组成的H泵产生。质膜（PM）H-ATPase是一种定位于质膜的H泵，在维持植物细胞和细胞外区域的pH稳态中起关键作用。PM H-ATPase的活性受蛋白质丰度和翻译后修饰的调节。已发现几种刺激通过羧基末端倒数第二个苏氨酸（Thr）的磷酸化来激活PM H-ATPase。光和光合作用诱导的PM H-ATPase磷酸化是各种植物物种中的保守现象。在这项工作中，我们综述了与植物光合组织中PM H-ATPase调节相关的最新发现，重点关注其机制和生理作用。在叶片中硝酸盐吸收和细胞质流动的背景下讨论了光合作用依赖性PM H-ATPase激活的生理作用。
