OsHT, a rice gene encoding for a plasma-membrane localized histidine transporter
OsHT, a rice gene encoding for a plasma-membrane localized histidine transporter
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DOI：
10.1111/j.1744-7909.2005.00016.x
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发表时间：
2005-01-01
影响因子：
11.4
通讯作者：
Zhu, YX
中科院分区：
文献类型：
--
作者：
Liu, D;Gong, W;Zhu, YX
根据拟南芥中已知的赖氨酸和组氨酸特异性氨基酸转运蛋白（LHT 1）的保守区设计了一个变性探针，克隆了水稻组氨酸转运蛋白（OsHT）的全长cDNA。筛选水稻cDNA文库。cDNA长度为1.3 kb，开放阅读框编码441个氨基酸的蛋白质，计算分子量为49 kDa。多序列比对结果表明，OsHT与拟南芥LHT 1及6个赖氨酸和组氨酸转运蛋白在推导的氨基酸水平上具有高度的保守性。计算分析表明，OsHT是一个完整的膜蛋白与11个推定的跨膜螺旋。这通过瞬时表达测定证实，因为OsHT-GFP融合蛋白确实主要定位于洋葱表皮细胞的质膜中。功能互补实验表明OsHT能够作为组氨酸转运蛋白在酿酒酵母中发挥作用，表明OsHT是一个编码水稻组氨酸转运蛋白的基因。这是首次从拟南芥以外的高等植物中克隆到LHT型氨基酸转运蛋白基因。
Using a degenerative probe designed according to the most conservative region of a known Lys- and His-specific amino acid transporter (LHT1) from Arabidopsis, we isolated a full-length cDNA named OsHT (histidine transporter of Oryza sativa L.) by screening the rice cDNA library. The cDNA is 1.3 kb in length and the open reading frame encodes for a 441 amino acid protein with a calculated molecular mass of 49 kDa. Multiple sequence alignments showed that OsHT shares a high degree of sequence conservation at the deduced amino acid level with the Arabidopsis LHT1 and six putative lysine and histidine transporters. Computational analysis indicated that OsHT is an integral membrane protein with 11 putative transmembrane helices. This was confirmed by the transient expression assay because the OsHT-GFP fusion protein was, indeed, localized mainly in the plasma membrane of onion epidermal cells. Functional complementation experiments demonstrated that OsHT was able to work as a histidine transporter in Saccharomyces cerevisiae, suggesting that OsHT is a gene that encodes for a histidine transporter from rice. This is the first time that an LHT-type amino acid transporter gene has been cloned from higher plants other than Arabidopsis.