8w9n

Structural highlights

Function

HKT1_ARATH Sodium transporter protein, which plays a central role in plant tolerance to salt. Upon prolongated exposure to high concentrations, Na(+) translocates from the roots to the transpiring leaves where it can increase to toxic level. Involved in Na(+) recirculation from shoots to roots, probably by mediating Na(+) loading into the phloem sap in shoots and unloading in roots, thereby removing large amounts of Na(+) from the shoot. Does not transport K(+) but regulates K(+) nutrient status via its ability to facilitate Na(+) homeostasis. Probably not involved in root uptake of Na(+).^{[1] [2] [3] [4] [5] [6] [7]}

References

1. ↑ Uozumi N, Kim EJ, Rubio F, Yamaguchi T, Muto S, Tsuboi A, Bakker EP, Nakamura T, Schroeder JI. The Arabidopsis HKT1 gene homolog mediates inward Na(+) currents in xenopus laevis oocytes and Na(+) uptake in Saccharomyces cerevisiae. Plant Physiol. 2000 Apr;122(4):1249-59. PMID:10759522 doi:10.1104/pp.122.4.1249
2. ↑ Rus A, Yokoi S, Sharkhuu A, Reddy M, Lee BH, Matsumoto TK, Koiwa H, Zhu JK, Bressan RA, Hasegawa PM. AtHKT1 is a salt tolerance determinant that controls Na(+) entry into plant roots. Proc Natl Acad Sci U S A. 2001 Nov 20;98(24):14150-5. PMID:11698666 doi:10.1073/pnas.241501798
3. ↑ Mäser P, Hosoo Y, Goshima S, Horie T, Eckelman B, Yamada K, Yoshida K, Bakker EP, Shinmyo A, Oiki S, Schroeder JI, Uozumi N. Glycine residues in potassium channel-like selectivity filters determine potassium selectivity in four-loop-per-subunit HKT transporters from plants. Proc Natl Acad Sci U S A. 2002 Apr 30;99(9):6428-33. PMID:11959905 doi:10.1073/pnas.082123799
4. ↑ Mäser P, Eckelman B, Vaidyanathan R, Horie T, Fairbairn DJ, Kubo M, Yamagami M, Yamaguchi K, Nishimura M, Uozumi N, Robertson W, Sussman MR, Schroeder JI. Altered shoot/root Na+ distribution and bifurcating salt sensitivity in Arabidopsis by genetic disruption of the Na+ transporter AtHKT1. FEBS Lett. 2002 Nov 6;531(2):157-61. PMID:12417304 doi:10.1016/s0014-5793(02)03488-9
5. ↑ Berthomieu P, Conéjéro G, Nublat A, Brackenbury WJ, Lambert C, Savio C, Uozumi N, Oiki S, Yamada K, Cellier F, Gosti F, Simonneau T, Essah PA, Tester M, Véry AA, Sentenac H, Casse F. Functional analysis of AtHKT1 in Arabidopsis shows that Na(+) recirculation by the phloem is crucial for salt tolerance. EMBO J. 2003 May 1;22(9):2004-14. PMID:12727868 doi:10.1093/emboj/cdg207
6. ↑ Rus A, Lee BH, Muñoz-Mayor A, Sharkhuu A, Miura K, Zhu JK, Bressan RA, Hasegawa PM. AtHKT1 facilitates Na+ homeostasis and K+ nutrition in planta. Plant Physiol. 2004 Sep;136(1):2500-11. PMID:15347798 doi:10.1104/pp.104.042234
7. ↑ Gong JM, Waner DA, Horie T, Li SL, Horie R, Abid KB, Schroeder JI. Microarray-based rapid cloning of an ion accumulation deletion mutant in Arabidopsis thaliana. Proc Natl Acad Sci U S A. 2004 Oct 26;101(43):15404-9. PMID:15486089 doi:10.1073/pnas.0404780101