Smith F W, Ealing P M, Hawkesford M J, Clarkson D T
Division of Tropical Crops and Pastures, Commonwealth Scientific and Industrial Research Organization, Cunningham Laboratory, St Lucia Old, Australia.
Proc Natl Acad Sci U S A. 1995 Sep 26;92(20):9373-7. doi: 10.1073/pnas.92.20.9373.
Three plant sulfate transporter cDNAs have been isolated by complementation of a yeast mutant with a cDNA library derived from the tropical forage legume Stylosanthes hamata. Two of these cDNAs, shst1 and shst2, encode high-affinity H+/sulfate cotransporters that mediate the uptake of sulfate by plant roots from low concentrations of sulfate in the soil solution. The third, shst3, represents a different subtype encoding a lower affinity H+/sulfate cotransporter, which may be involved in the internal transport of sulfate between cellular or subcellular compartments within the plant. The steady-state level of mRNA corresponding to both subtypes is subject to regulation by signals that ultimately respond to the external sulfate supply. These cDNAs represent the identification of plant members of a family of related sulfate transporter proteins whose sequences exhibit significant amino acid conservation in filamentous fungi, yeast, plants, and mammals.
通过用来自热带豆科牧草链荚豆的cDNA文库对酵母突变体进行互补，已分离出三个植物硫酸盐转运体cDNA。其中两个cDNA，即shst1和shst2，编码高亲和力的H⁺/硫酸盐共转运体，介导植物根系从土壤溶液中低浓度硫酸盐摄取硫酸盐。第三个cDNA，即shst3，代表一种不同的亚型，编码较低亲和力的H⁺/硫酸盐共转运体，可能参与植物细胞内或亚细胞区室之间硫酸盐的内部转运。对应于这两种亚型的mRNA稳态水平受最终响应外部硫酸盐供应的信号调控。这些cDNA代表了一个相关硫酸盐转运蛋白家族的植物成员的鉴定，其序列在丝状真菌、酵母、植物和哺乳动物中表现出显著的氨基酸保守性。
