A novel family of magnesium transport genes in Arabidopsis
A novel family of magnesium transport genes in Arabidopsis
复制标题
DOI：
10.1105/tpc.13.12.2761
复制
发表时间：
2001-12-01
期刊：
影响因子：
11.6
通讯作者：
Luan, S
中科院分区：
文献类型：
--
作者：
Li, LG;Tutone, AF;Luan, S
镁（Mg 2+）是植物细胞中含量最丰富的二价阳离子，在许多生理过程中起着重要作用。我们描述了一个10个成员的拟南芥基因家族（AtMGT）编码推定的Mg 2+转运蛋白的鉴定。AtMGT家族的大多数成员在一系列拟南芥组织中表达。该家族的一个成员AtMGT 1在功能上补充了缺乏Mg 2+转运能力的细菌突变体。第二个成员，AtMGT 10，补充了酵母突变体的Mg 2+摄取缺陷，并增加了细胞Mg 2+含量的饥饿细胞在60分钟的摄取期间的三倍。在细菌中的Ni-63示踪剂研究表明，AtMOT 1对Mg 2+具有最高的亲和力，但也可能能够运输几种其他二价阳离子，包括Ni 2+，Co2+，Fe 2+，Mn 2+和Cu 2+。然而，运输这些其他阳离子所需的浓度超出了正常的生理范围。AtMGT 1和AtMGT 10对Al ~（3+）的抑制作用高度敏感，为研究Al ~（3+）对植物的毒害作用提供了潜在的分子靶点。利用绿色荧光蛋白作为报告基因，我们将AtMGT 1蛋白定位于拟南芥的质膜上。我们认为AtMGT基因家族编码高等植物中的Mg ~（2+）转运系统。
Magnesium (Mg2+) is the most abundant divalent cation in plant cells and plays a critical role in many physiological processes. We describe the identification of a 10-member Arabidopsis gene family (AtMGT) encoding putative Mg2+ transport proteins. Most members of the AtMGT family are expressed in a range of Arabidopsis tissues. One member of this family, AtMGT1, functionally complemented a bacterial mutant lacking Mg2+ transport capability. A second member, AtMGT10, complemented a yeast mutant defective in Mg2+ uptake and increased the cellular Mg2+ content of starved cells threefold during a 60-min uptake period. Ni-63 tracer studies in bacteria showed that AtMOT1 has highest affinity for Mg2+ but may also be capable of transporting several other divalent cations, including Ni2+, Co2+, Fe2+, Mn2+, and Cu2+. However, the concentrations required for transport of these other cations are beyond normal physiological ranges. Both AtMGT1 and AtMGT10 are highly sensitive to Al3+ inhibition, providing potential molecular targets for Al3+ toxicity in plants. Using green fluorescence protein as a reporter, we localized AtMGT1 protein to the plasma membrane in Arabidopsis plants. We suggest that the AtMGT gene family encodes a Mg2+ transport system in higher plants.