The F130S point mutation in the Arabidopsis high-affinity K(+) transporter AtHAK5 increases K(+) over Na(+) and Cs(+) selectivity and confers Na(+) and Cs(+) tolerance to yeast under heterologous expression.
The F130S point mutation in the Arabidopsis high-affinity K(+) transporter AtHAK5 increases K(+) over Na(+) and Cs(+) selectivity and confers Na(+) and Cs(+) tolerance to yeast under heterologous expression.
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拟南芥高亲和力K（+）转运蛋白athak5中的F130S点突变增加了K（+）和CS（+）和CS（+）选择性，并赋予Na（+）和CS（+）在异源表达下对酵母的CS（+）耐受性。
DOI：
10.3389/fpls.2014.00430
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发表时间：
2014
影响因子：
5.6
通讯作者：
Rubio F
中科院分区：
文献类型：
--
作者：
Alemán F;Caballero F;Ródenas R;Rivero RM;Martínez V;Rubio F
钾（K+）是植物生长发育和作物高产所必需的大量营养元素。KT/HAK/KUP转运蛋白家族的I组成员，如HAK 5，是植物根系在低K+浓度下吸收K+的关键组分。某些非生物胁迫条件，如盐或Cs+污染的土壤可能会危及植物K+营养，因为HAK 5介导的K+运输被Na+和Cs+抑制。在这里，通过在酵母中筛选随机突变的AtHAK 5转运蛋白集合，鉴定了AtHAK 5序列中的新突变，其大大增加了Na+耐受性。单点突变F130 S，影响HAK 5转运蛋白中保守的氨基酸残基，从几个物种，赋予高盐耐受性，以及Cs+耐受性。该突变使AtHAK 5对K+的亲和力增加了100倍以上，并降低了Na+和Cs+的Ki值，这表明F130残基可能有助于K+结合所涉及的孔区域的结构。此外，该突变增加了K+的Vmax。所有这些变化的发生都没有增加酵母中AtHAK 5蛋白的量，并支持这种残基有助于形成AtHAK 5转运蛋白的选择性过滤器的想法。
Potassium (K+) is an essential macronutrient required for plant growth, development and high yield production of crops. Members of group I of the KT/HAK/KUP family of transporters, such as HAK5, are key components for K+ acquisition by plant roots at low external K+ concentrations. Certain abiotic stress conditions such as salinity or Cs+-polluted soils may jeopardize plant K+ nutrition because HAK5-mediated K+ transport is inhibited by Na+ and Cs+. Here, by screening in yeast a randomly-mutated collection of AtHAK5 transporters, a new mutation in AtHAK5 sequence is identified that greatly increases Na+ tolerance. The single point mutation F130S, affecting an amino acid residue conserved in HAK5 transporters from several species, confers high salt tolerance, as well as Cs+ tolerance. This mutation increases more than 100-fold the affinity of AtHAK5 for K+ and reduces the Ki values for Na+ and Cs+, suggesting that the F130 residue may contribute to the structure of the pore region involved in K+ binding. In addition, this mutation increases the Vmax for K+. All this changes occur without increasing the amount of the AtHAK5 protein in yeast and support the idea that this residue is contributing to shape the selectivity filter of the AtHAK5 transporter.
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影响因子：
14.8
作者：
Gietz, R. Daniel;Schiestl, Robert H.
通讯作者：
Schiestl, Robert H.
影响因子：
3.5
作者：
MacKinnon, R
通讯作者：
MacKinnon, R
影响因子：
3.5
作者：
Mangano, Silvina;Silberstein, Susana;Santa-Maria, Guillermo E.
通讯作者：
Santa-Maria, Guillermo E.
影响因子：
4.9
作者：
Caballero, Fernando;Botella, Maria A.;Rubio, Francisco
通讯作者：
Rubio, Francisco
影响因子：
11.4
作者：
BANUELOS, MA;KLEIN, RD;RODRIGUEZNAVARRO, A
通讯作者：
RODRIGUEZNAVARRO, A