Defining the role of the two vacuolar proton-pumps during stress responses

虽然一般认为液泡H+- atp酶（V-ATPase）和液泡H+-焦磷酸酶（V-PPase）的联合作用促进了线粒体的运输，但它们在低温和渗透胁迫下对液泡和细胞质ph稳态的相对贡献尚未确定。在第一个资助期，我们已经确定在非胁迫条件下，V-PPase不会促进液泡酸化。令人惊讶的是，我们发现除了细胞质V-ATPase外，内体VATPase似乎在液泡酸化和胁迫耐受中起重要作用。基于这些结果，重点将放在v - atp酶在膜室动态连续体中的功能和调控上，最终将货物运送到中央液泡。此外，我们将继续努力，通过使用pH和关键代谢物的纳米传感器来确定V-PPase在寒冷和渗透胁迫下的作用。

Although it is generally assumed that the combined action of the vacuolar H+-ATPase (V-ATPase) and the vacuolar H+-pyrophosphatase (V-PPase) energizes transport across the tonoplast, their relative contribution to vacuolar and cytosolic pH-homeostasis during coldand osmotic stress has not been determined. During the first funding period, we have established that under non-stress conditions the V-PPase does not contribute to vacuolar acidification. Surprisingly, we found that in addition to the tonoplast V-ATPase, the endosomal VATPase seems to play an important role in vacuolar acidification and stress tolerance. Based on these results, focus will be on the function and regulation of the V-ATPase in the dynamic continuum of endomembrane compartments that ultimately delivers cargo to the central vacuole. In addition, we will continue our efforts to determine the role of the V-PPase under cold- and osmotic stress by using nanosensors for pH and key metabolites.