Li Yanbang, Provenzano Sofia, Bliek Mattijs, Spelt Cornelis, Appelhagen Ingo, Machado de Faria Laura, Verweij Walter, Schubert Andrea, Sagasser Martin, Seidel Thorsten, Weisshaar Bernd, Koes Ronald, Quattrocchio Francesca
Department of Plant Development and (Epi)Genetics, Swammerdam Institute for Life Sciences, University of Amsterdam, 1098XH, Amsterdam, the Netherlands.
Department of Molecular and Cell Biology, VU-University, De Boelelaan 1081, 1071 HK, Amsterdam, the Netherlands.
New Phytol. 2016 Aug;211(3):1092-107. doi: 10.1111/nph.14008. Epub 2016 May 23.
Petunia mutants (Petunia hybrida) with blue flowers defined a novel vacuolar proton pump consisting of two interacting P-ATPases, PH1 and PH5, that hyper-acidify the vacuoles of petal cells. PH5 is similar to plasma membrane H(+) P3A -ATPase, whereas PH1 is the only known eukaryoticP3B -ATPase. As there were no indications that this tonoplast pump is widespread in plants, we investigated the distribution and evolution of PH1 and PH5. We combined database mining and phylogenetic and synteny analyses of PH1- and PH5-like proteins from all kingdoms with functional analyses (mutant complementation and intracellular localization) of homologs from diverse angiosperms. We identified functional PH1 and PH5 homologs in divergent angiosperms. PH5 homologs evolved from plasma membrane P3A -ATPases, acquiring an N-terminal tonoplast-sorting sequence and new cellular function before angiosperms appeared. PH1 is widespread among seed plants and related proteins are found in some groups of bacteria and fungi and in one moss, but is absent in most algae, suggesting that its evolution involved several cases of gene loss and possibly horizontal transfer events. The distribution of PH1 and PH5 in the plant kingdom suggests that vacuolar acidification by P-ATPases appeared in gymnosperms before flowers. This implies that, next to flower color determination, vacuolar hyper-acidification is required for yet unknown processes.
具有蓝色花朵的矮牵牛突变体（矮牵牛）定义了一种新型液泡质子泵，它由两个相互作用的P型ATP酶PH1和PH5组成，可使花瓣细胞的液泡过度酸化。PH5类似于质膜H(+) P3A -ATP酶，而PH1是唯一已知的真核生物P3B -ATP酶。由于没有迹象表明这种液泡膜泵在植物中广泛存在，我们研究了PH1和PH5的分布及进化情况。我们将来自所有生物界的PH1和PH5样蛋白的数据库挖掘、系统发育和共线性分析与来自不同被子植物的同源物的功能分析（突变体互补和细胞内定位）相结合。我们在不同的被子植物中鉴定出了功能性的PH1和PH5同源物。PH5同源物从质膜P3A -ATP酶进化而来，在被子植物出现之前获得了一个N端液泡膜分选序列和新的细胞功能。PH1在种子植物中广泛存在，在一些细菌、真菌类群以及一种苔藓中发现了相关蛋白，但在大多数藻类中不存在，这表明其进化涉及几例基因丢失事件以及可能的水平转移事件。PH1和PH5在植物界的分布表明，P型ATP酶介导的液泡酸化在裸子植物中出现在花朵出现之前。这意味着，除了决定花色外，液泡过度酸化对于一些未知过程也是必需的。
