Plant Development and (Epi)Genetics, Swammerdam Institute for Life Science, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, the Netherlands; Section of Genetics, Department of Molecular Cell Biology, VU University, de Boelelaan 1087, 1081 HV Amsterdam, the Netherlands; Department of Biotechnology and Environmental Sciences, University of Salento, via Monteroni, Centro Ecotekne, 73100 Lecce, Italy.
Plant Development and (Epi)Genetics, Swammerdam Institute for Life Science, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, the Netherlands; Section of Genetics, Department of Molecular Cell Biology, VU University, de Boelelaan 1087, 1081 HV Amsterdam, the Netherlands.
Cell Rep. 2017 Jun 20;19(12):2413-2422. doi: 10.1016/j.celrep.2017.05.076.
It is known that plant cells can contain multiple distinct vacuoles; however, the abundance of multivacuolar cells and the mechanisms underlying vacuolar differentiation and communication among different types of vacuoles remain unknown. PH1 and PH5 are tonoplast P-ATPases that form a heteromeric pump that hyper-acidifies the central vacuole (CV) of epidermal cells in petunia petals. Here, we show that the sorting of this pump and other vacuolar proteins to the CV involves transit through small vacuoles: vacuolinos. Vacuolino formation is controlled by transcription factors regulating pigment synthesis and transcription of PH1 and PH5. Trafficking of proteins from vacuolinos to the central vacuole is impaired by misexpression of vacuolar SNAREs as well as mutants for the PH1 component of the PH1-PH5 pump. The finding that PH1-PH5 and these SNAREs interact strongly suggests that structural tonoplast proteins can act as tethering factors in the recognition of different vacuolar types.
已知植物细胞可以包含多个不同的液泡；然而，多液泡细胞的丰度以及液泡分化和不同类型液泡之间通讯的机制尚不清楚。PH1 和 PH5 是液泡膜 P-ATP 酶，它们形成一个异源泵，使矮牵牛花瓣表皮细胞的中央液泡（CV）过度酸化。在这里，我们表明，该泵和其他液泡蛋白向 CV 的分拣涉及通过小液泡：液泡小泡的转运。液泡小泡的形成受调节色素合成和 PH1 和 PH5 转录的转录因子控制。液泡小泡到中央液泡的蛋白质运输受到液泡 SNAREs 的错误表达以及 PH1-PH5 泵的 PH1 成分突变体的阻碍。发现 PH1-PH5 和这些 SNAREs 强烈相互作用表明，结构液泡膜蛋白可以作为识别不同液泡类型的连接因子。
