磷酸化和去磷酸化对木榄细胞膜Na+/H+逆转运蛋白功能的调节

项目名称： 磷酸化和去磷酸化对木榄细胞膜Na+/H+逆转运蛋白功能的调节

项目编号： No.31260218

项目类型： 地区科学基金项目

立项/批准年度： 2013

项目学科： 生物科学

项目作者： 江行玉

作者单位： 海南大学

项目金额： 50万元

中文摘要： SOS1负责Na+/H+反向运输，是至今发现的细胞膜上唯一能把Na+从细胞内运输到细胞外的蛋白质。木榄是一种盐生植物，具有很强的耐盐能力，其根部能把吸收到体内99%的盐分再排出体外，这说明其质膜上的Na+外向运输蛋白具有很强的活性，因此木榄应该是研究植物SOS1蛋白功能的绝好材料。我们根据木榄BgSOS1的序列信息从木榄中克隆到了全长的BgSOS1基因，在初步研究了它的功能，并发现BgSOS1序列上新磷酸化位点的基础上，现在正利用相应的酵母和拟南芥突变体以及纯化BgSOS1蛋白，人工蛋白脂质体和蛋白磷酸化技术研究SOS2-SOS3蛋白激酶复合体和2C-型蛋白磷酸酶通过磷酸化和去磷酸化对BgSOS1功能的调节，再进一步鉴定BgSOS1序列上的磷酸化和去磷酸化位点，研究它的自身功能抑制区，筛选出耐盐性较高的BgSOS1突变基因，为探讨植物的耐盐机理提供理论证据和为培育较强耐盐性的作物提供材料。

中文关键词： 木榄；抗盐机理；磷酸化；细胞膜；Na+/H+逆向运输蛋白

英文摘要： The Na+/H+ antiporter SOS1 is the only Na+ efflux protein at the plasma membrane of plants characterized so far, so it may play an important role in the plant tolerance to salinity. As a strong halophyte, the roots of Bruguiera gymnorhiza can exclude 99% salts, indicating that the Na+ efflux proteins at plasma membrane may function very well, so it should be a perfect plant to study the function of SOS1. The full length of the gene of Bruguiera gymnorhiza SOS1 (BgSOS1) has been cloned in our laboratory, its function has simply been studied, but also the new phosphorylation site in its squenece has been discovered. Based on our research work about BgSOS1 and taking into account my research experiences with Na+ transporters in other plants, we are studying the regulation of phosphorylation by SOS2-SOS3 protein kinase complex and dephosphorylation by 2C-type protein phosphatase (PP2C) on Na+/H+ antiport function of BgSOS1, and shall further identify its phosphorylation site and dephosphorylation site. In addition, we shall screen hyperactive SOS1 mutant gene by studying function inhibition domain in the sequence of BgSOS1. These will be helpful to elucidate the tolerance mechanism of plants to salinity and offer candidate genes to cultivate salt tolerant corps.

英文关键词： Bruguiera gymnorhiza；Mechanism of salt resistance；phosphorylation；plasma membrane；Na+/H+ antiporter