Control of eukaryotic phosphate homeostasis by inositol polyphosphate sensor domains
Control of eukaryotic phosphate homeostasis by inositol polyphosphate sensor domains
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DOI：
10.1126/science.aad9858
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发表时间：
2016-05-20
期刊：
影响因子：
56.9
通讯作者：
Mayer, Andreas
中科院分区：
文献类型：
--
作者：
Wild, Rebekka;Gerasimaite, Ruta;Mayer, Andreas
磷是细胞以无机磷酸盐（Pi）形式吸收的大量营养素。细胞如何感知细胞Pi水平的特征很差。在这里，我们报告说，SPX结构域-这是真核磷酸盐转运蛋白，信号蛋白，和无机聚磷酸盐聚合酶-提供了一个基本的结合表面肌醇多磷酸信号分子（InsPs），其浓度的变化响应于Pi的可用性。关键结合表面残基的取代损害InsP结合在体外，无机多磷酸盐在酵母中的合成，和拟南芥中的Pi运输。在植物中，InsPs触发SPX蛋白与转录因子的关联以调节Pi饥饿反应。我们建议InsPs将胞质Pi水平与SPX结构域进行通信，并使它们能够与多种蛋白质相互作用，以调节真菌，植物和动物中的Pi摄取，运输和储存。
Phosphorus is a macronutrient taken up by cells as inorganic phosphate (Pi). How cells sense cellular Pi levels is poorly characterized. Here, we report that SPX domains-which are found in eukaryotic phosphate transporters, signaling proteins, and inorganic polyphosphate polymerases-provide a basic binding surface for inositol polyphosphate signaling molecules (InsPs), the concentrations of which change in response to Pi availability. Substitutions of critical binding surface residues impair InsP binding in vitro, inorganic polyphosphate synthesis in yeast, and Pi transport in Arabidopsis. In plants, InsPs trigger the association of SPX proteins with transcription factors to regulate Pi starvation responses. We propose that InsPs communicate cytosolic Pi levels to SPX domains and enable them to interact with a multitude of proteins to regulate Pi uptake, transport, and storage in fungi, plants, and animals.