Analysis of trehalose-6-phosphate synthase (TPS) gene family suggests the formation of TPS complexes in rice
Analysis of trehalose-6-phosphate synthase (TPS) gene family suggests the formation of TPS complexes in rice
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海藻糖-6-磷酸合酶 (TPS) 基因家族的分析表明水稻中 TPS 复合物的形成
DOI：
10.1007/s11103-011-9781-1
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发表时间：
2011-08-01
影响因子：
5.1
通讯作者：
Wang, Xiping
中科院分区：
文献类型：
--
作者：
Zang, Baisheng;Li, Haowen;Wang, Xiping
海藻糖-6-磷酸(T6P)是海藻糖生物合成途径的中间产物，是植物新陈代谢和发育的重要调节因子。T6P水平可能受一组海藻糖-6-磷酸合成酶(TPS)和海藻糖-6-磷酸磷酸酶(TPP)同源物的调节。在本研究中，我们从水稻中分离到了11个TPS基因，编码具有TPS和TPP结构域的蛋白。对酵母突变株1和突变体tps 2进行的功能互补分析表明，只有OsTPS1编码有活性的TPS酶，没有OsTPS蛋白具有TPP活性。通过酵母双杂交分析，OsTPS蛋白之间出现了一个复杂的相互作用网络，TPS结构域可能是这种相互作用发生的关键。通过双分子荧光互补和免疫共沉淀实验证实了OsTPS1和OsTPS8在体内的相互作用。此外，我们的凝胶过滤实验表明，水稻中可能存在两种形式的OsTPS1(OsTPS1a和OsTPS1b)，它们的洗脱曲线不同。在360 kDa的复合体中，OsTPS1b与OsTPS5和OsTPS8特别共分，而OsTPS1a主要结合在大于360 kDa的复合体中。总之，这些结果表明，OsTP家族成员可能形成海藻糖-6-磷酸合成酶复合体，因此有可能改变T6P的水平来调节植物的发育。
Trehalose-6-phosphate (T6P), an intermediate in the trehalose biosynthesis pathway, is emerging as an important regulator of plant metabolism and development. T6P levels are potentially modulated by a group of trehalose-6-phosphate synthase (TPS) and trehalose-6-phosphate phosphatase (TPP) homologues. In this study, we have isolated 11TPSgenes encoding proteins with both TPS and TPP domains, from rice. Functional complement assays performed in yeasttps1andtps2mutants, revealed that onlyOsTPS1encodes an active TPS enzyme and no OsTPS protein possesses TPP activity. By using a yeast two-hybrid analysis, a complicated interaction network occurred among OsTPS proteins, and the TPS domain might be essential for this interaction to occur. The interaction between OsTPS1 and OsTPS8 in vivo was confirmed by bimolecular fluorescence complementation and coimmunoprecipitation assays. Furthermore, our gel filtration assay showed that there may exist two forms of OsTPS1 (OsTPS1a and OsTPS1b) with different elution profiles in rice. OsTPS1b was particularly cofractionated with OsTPS5 and OsTPS8 in the 360 kDa complex, while OsTPS1a was predominantly incorporated into the complexes larger than 360 kDa. Collectively, these results suggest that OsTPSfamily members may form trehalose-6-phosphate synthase complexes and therefore potentially modify T6P levels to regulate plant development.