Ketchum K A, Slayman C W
Department of Genetics, Yale University School of Medicine, New Haven, CT 06510, USA.
FEBS Lett. 1996 Jan 2;378(1):19-26. doi: 10.1016/0014-5793(95)01417-9.
A degenerate oligonucleotide corresponding to the K+ channel signature sequence (TMTTVGYGD) was used to isolate the genomic and cDNA forms of a new channel gene, AKT3, from Arabidopsis thaliana. The deduced protein sequence has a predicted membrane topography similar to Shaker-like K+ channels. Three distinct modules comprise the carboxyl-terminal half: a nucleotide-binding motif, an ankyrin repeat domain, and a polyglutamate track. Xenopus oocytes injected with cRNA exhibited an inward-rectifying K+ current, demonstrating that the AKT3 polypeptide is a functional transport protein. Two other Arabidopsis K+ transporters (AKT1 and KAT1) share 60% homology with AKT3; together these proteins constitute a family of plant inward-rectifying K+ channels.
一个与钾离子通道特征序列（TMTTVGYGD）对应的简并寡核苷酸被用于从拟南芥中分离一个新通道基因AKT3的基因组和cDNA形式。推导的蛋白质序列具有与类Shaker钾离子通道相似的预测膜拓扑结构。三个不同的模块构成了羧基末端的一半：一个核苷酸结合基序、一个锚蛋白重复结构域和一个多聚谷氨酸序列。注射了cRNA的非洲爪蟾卵母细胞表现出内向整流钾电流，表明AKT3多肽是一种功能性转运蛋白。另外两个拟南芥钾离子转运体（AKT1和KAT1）与AKT3有60%的同源性；这些蛋白共同构成了一个植物内向整流钾离子通道家族。
