• We are sorry, but NCBI web applications do not support your browser and may not function properly. More information
Logo of plntcellLink to Publisher's site
Plant Cell. Jan 1998; 10(1): 51–62.
PMCID: PMC143935

AtKUP1: an Arabidopsis gene encoding high-affinity potassium transport activity.

Abstract

Because plants grow under many different types of soil and environmental conditions, we investigated the hypothesis that multiple pathways for K+ uptake exist in plants. We have identified a new family of potassium transporters from Arabidopsis by searching for homologous sequences among the expressed sequence tags of the GenBank database. The deduced amino acid sequences of AtKUP (for Arabidopsis thaliana K+ uptake transporter) cDNAs are highly homologous to the non-plant Kup and HAK1 potassium transporters from Escherichia coli and Schwanniomyces occidentalis, respectively. Interestingly, AtKUP1 and AtKUP2 are able to complement the potassium transport deficiency of an E. coli triple mutant. In addition, transgenic Arabidopsis suspension cells overexpressing AtKUP1 showed increased Rb+ uptake at micromolar concentrations with an apparent K(m) of approximately 22 microM, indicating that AtKUP1 encodes a high-affinity potassium uptake activity in vivo. A small, low-affinity Rb+ uptake component was also detected in AtKUP1-expressing cells. RNA gel blot analysis showed that the various members of the AtKUP family have distinct patterns of expression, with AtKUP3 transcript levels being strongly induced by K+ starvation. It is proposed that plants contain multiple potassium transporters for high-affinity uptake and that the AtKUP family may provide important components of high- and low-affinity K+ nutrition and uptake into various plant cell types.

Full Text

The Full Text of this article is available as a PDF (314K).

Selected References

These references are in PubMed. This may not be the complete list of references from this article.
  • Altschul SF, Gish W, Miller W, Myers EW, Lipman DJ. Basic local alignment search tool. J Mol Biol. 1990 Oct 5;215(3):403–410. [PubMed]
  • Anderson JA, Huprikar SS, Kochian LV, Lucas WJ, Gaber RF. Functional expression of a probable Arabidopsis thaliana potassium channel in Saccharomyces cerevisiae. Proc Natl Acad Sci U S A. 1992 May 1;89(9):3736–3740. [PMC free article] [PubMed]
  • Bañuelos MA, Klein RD, Alexander-Bowman SJ, Rodríguez-Navarro A. A potassium transporter of the yeast Schwanniomyces occidentalis homologous to the Kup system of Escherichia coli has a high concentrative capacity. EMBO J. 1995 Jul 3;14(13):3021–3027. [PMC free article] [PubMed]
  • Bertl A, Anderson JA, Slayman CL, Sentenac H, Gaber RF. Inward and outward rectifying potassium currents in Saccharomyces cerevisiae mediated by endogenous and heterelogously expressed ion channels. Folia Microbiol (Praha) 1994;39(6):507–509. [PubMed]
  • Bossemeyer D, Schlösser A, Bakker EP. Specific cesium transport via the Escherichia coli Kup (TrkD) K+ uptake system. J Bacteriol. 1989 Apr;171(4):2219–2221. [PMC free article] [PubMed]
  • Bush DR, Jacobson L. Potassium transport in suspension culture cells and protoplasts of carrot. Plant Physiol. 1986 Aug;81(4):1022–1026. [PMC free article] [PubMed]
  • Buurman ET, Kim KT, Epstein W. Genetic evidence for two sequentially occupied K+ binding sites in the Kdp transport ATPase. J Biol Chem. 1995 Mar 24;270(12):6678–6685. [PubMed]
  • Cao Y, Anderova M, Crawford NM, Schroeder JI. Expression of an outward-rectifying potassium channel from maize mRNA and complementary RNA in Xenopus oocytes. Plant Cell. 1992 Aug;4(8):961–969. [PMC free article] [PubMed]
  • Crawford NM. Nitrate: nutrient and signal for plant growth. Plant Cell. 1995 Jul;7(7):859–868. [PMC free article] [PubMed]
  • Ding L, Zhu JK. Reduced Na+ uptake in the NaCl-hypersensitive sos1 mutant of Arabidopsis thaliana. Plant Physiol. 1997 Mar;113(3):795–799. [PMC free article] [PubMed]
  • Dosch DC, Helmer GL, Sutton SH, Salvacion FF, Epstein W. Genetic analysis of potassium transport loci in Escherichia coli: evidence for three constitutive systems mediating uptake potassium. J Bacteriol. 1991 Jan;173(2):687–696. [PMC free article] [PubMed]
  • Elble R. A simple and efficient procedure for transformation of yeasts. Biotechniques. 1992 Jul;13(1):18–20. [PubMed]
  • Epstein E, Rains DW. CARRIER-MEDIATED CATION TRANSPORT IN BARLEY ROOTS: KINETIC EVIDENCE FOR A SPECTRUM OF ACTIVE SITES. Proc Natl Acad Sci U S A. 1965 Jun;53(6):1320–1324. [PMC free article] [PubMed]
  • Epstein E, Rains DW, Elzam OE. RESOLUTION OF DUAL MECHANISMS OF POTASSIUM ABSORPTION BY BARLEY ROOTS. Proc Natl Acad Sci U S A. 1963 May;49(5):684–692. [PMC free article] [PubMed]
  • Epstein W, Kim BS. Potassium transport loci in Escherichia coli K-12. J Bacteriol. 1971 Nov;108(2):639–644. [PMC free article] [PubMed]
  • Epstein W, Buurman E, McLaggan D, Naprstek J. Multiple mechanisms, roles and controls of K+ transport in Escherichia coli. Biochem Soc Trans. 1993 Nov;21(4):1006–1010. [PubMed]
  • Fernando M, Mehroke J, Glass AD. De Novo Synthesis of Plasma Membrane and Tonoplast Polypeptides of Barley Roots during Short-Term K Deprivation : In Search of the High-Affinity K Transport System. Plant Physiol. 1992 Nov;100(3):1269–1276. [PMC free article] [PubMed]
  • Fu HH, Luan S. AtKuP1: a dual-affinity K+ transporter from Arabidopsis. Plant Cell. 1998 Jan;10(1):63–73. [PMC free article] [PubMed]
  • Gaber RF, Styles CA, Fink GR. TRK1 encodes a plasma membrane protein required for high-affinity potassium transport in Saccharomyces cerevisiae. Mol Cell Biol. 1988 Jul;8(7):2848–2859. [PMC free article] [PubMed]
  • Gassmann W, Schroeder JI. Inward-Rectifying K+ Channels in Root Hairs of Wheat (A Mechanism for Aluminum-Sensitive Low-Affinity K+ Uptake and Membrane Potential Control). Plant Physiol. 1994 Aug;105(4):1399–1408. [PMC free article] [PubMed]
  • Gassmann W, Ward JM, Schroeder JI. Physiological Roles of Inward-Rectifying K+ Channels. Plant Cell. 1993 Nov;5(11):1491–1493. [PMC free article] [PubMed]
  • Gassman W, Rubio F, Schroeder JI. Alkali cation selectivity of the wheat root high-affinity potassium transporter HKT1. Plant J. 1996 Nov;10(5):869–852. [PubMed]
  • Glass A. The regulation of potassium absorption in barley roots. Plant Physiol. 1975 Sep;56(3):377–380. [PMC free article] [PubMed]
  • Harper JF, Surowy TK, Sussman MR. Molecular cloning and sequence of cDNA encoding the plasma membrane proton pump (H+-ATPase) of Arabidopsis thaliana. Proc Natl Acad Sci U S A. 1989 Feb;86(4):1234–1238. [PMC free article] [PubMed]
  • Hesse JE, Wieczorek L, Altendorf K, Reicin AS, Dorus E, Epstein W. Sequence homology between two membrane transport ATPases, the Kdp-ATPase of Escherichia coli and the Ca2+-ATPase of sarcoplasmic reticulum. Proc Natl Acad Sci U S A. 1984 Aug;81(15):4746–4750. [PMC free article] [PubMed]
  • Ketchum KA, Slayman CW. Isolation of an ion channel gene from Arabidopsis thaliana using the H5 signature sequence from voltage-dependent K+ channels. FEBS Lett. 1996 Jan 2;378(1):19–26. [PubMed]
  • Ketchum KA, Joiner WJ, Sellers AJ, Kaczmarek LK, Goldstein SA. A new family of outwardly rectifying potassium channel proteins with two pore domains in tandem. Nature. 1995 Aug 24;376(6542):690–695. [PubMed]
  • Ko CH, Buckley AM, Gaber RF. TRK2 is required for low affinity K+ transport in Saccharomyces cerevisiae. Genetics. 1990 Jun;125(2):305–312. [PMC free article] [PubMed]
  • Kochian LV, Lucas WJ. Potassium transport in corn roots : I. Resolution of kinetics into a saturable and linear component. Plant Physiol. 1982 Dec;70(6):1723–1731. [PMC free article] [PubMed]
  • Kochian LV, Shaff JE, Lucas WJ. High affinity k uptake in maize roots: a lack of coupling with h efflux. Plant Physiol. 1989 Nov;91(3):1202–1211. [PMC free article] [PubMed]
  • Kwak JM, Kim SA, Hong SW, Nam HG. Evaluation of 515 expressed sequence tags obtained from guard cells of Brassica campestris. Planta. 1997;202(1):9–17. [PubMed]
  • Kyte J, Doolittle RF. A simple method for displaying the hydropathic character of a protein. J Mol Biol. 1982 May 5;157(1):105–132. [PubMed]
  • Liman ER, Tytgat J, Hess P. Subunit stoichiometry of a mammalian K+ channel determined by construction of multimeric cDNAs. Neuron. 1992 Nov;9(5):861–871. [PubMed]
  • Maathuis FJ, Sanders D. Mechanism of high-affinity potassium uptake in roots of Arabidopsis thaliana. Proc Natl Acad Sci U S A. 1994 Sep 27;91(20):9272–9276. [PMC free article] [PubMed]
  • Maathuis FJ, Sanders D. Contrasting roles in ion transport of two K(+)-channel types in root cells of Arabidopsis thaliana. Planta. 1995;197(3):456–464. [PubMed]
  • Maathuis FJM, Verlin D, Smith FA, Sanders D, Fernandez JA, Walker NA. The Physiological Relevance of Na+-Coupled K+-Transport. Plant Physiol. 1996 Dec;112(4):1609–1616. [PMC free article] [PubMed]
  • Mitsukawa N, Okumura S, Shirano Y, Sato S, Kato T, Harashima S, Shibata D. Overexpression of an Arabidopsis thaliana high-affinity phosphate transporter gene in tobacco cultured cells enhances cell growth under phosphate-limited conditions. Proc Natl Acad Sci U S A. 1997 Jun 24;94(13):7098–7102. [PMC free article] [PubMed]
  • Newman IA, Kochian LV, Grusak MA, Lucas WJ. Fluxes of h and k in corn roots : characterization and stoichiometries using ion-selective microelectrodes. Plant Physiol. 1987 Aug;84(4):1177–1184. [PMC free article] [PubMed]
  • Odell JT, Nagy F, Chua NH. Identification of DNA sequences required for activity of the cauliflower mosaic virus 35S promoter. Nature. 313(6005):810–812. [PubMed]
  • Park YS, Kwak JM, Kwon OY, Kim YS, Lee DS, Cho MJ, Lee HH, Nam HG. Generation of expressed sequence tags of random root cDNA clones of Brassica napus by single-run partial sequencing. Plant Physiol. 1993 Oct;103(2):359–370. [PMC free article] [PubMed]
  • Quintero FJ, Blatt MR. A new family of K+ transporters from Arabidopsis that are conserved across phyla. FEBS Lett. 1997 Sep 29;415(2):206–211. [PubMed]
  • Rhoads DB, Waters FB, Epstein W. Cation transport in Escherichia coli. VIII. Potassium transport mutants. J Gen Physiol. 1976 Mar;67(3):325–341. [PMC free article] [PubMed]
  • Rodríguez-Navarro A, Ramos J. Dual system for potassium transport in Saccharomyces cerevisiae. J Bacteriol. 1984 Sep;159(3):940–945. [PMC free article] [PubMed]
  • Rubio F, Gassmann W, Schroeder JI. Sodium-driven potassium uptake by the plant potassium transporter HKT1 and mutations conferring salt tolerance. Science. 1995 Dec 8;270(5242):1660–1663. [PubMed]
  • Rubio F, Gassmann W, Schroeder JI. Response: high-affinity potassium uptake in plants. Science. 1996 Aug 16;273(5277):978–979. [PubMed]
  • Schachtman DP, Schroeder JI. Structure and transport mechanism of a high-affinity potassium uptake transporter from higher plants. Nature. 1994 Aug 25;370(6491):655–658. [PubMed]
  • Schachtman DP, Schroeder JI, Lucas WJ, Anderson JA, Gaber RF. Expression of an inward-rectifying potassium channel by the Arabidopsis KAT1 cDNA. Science. 1992 Dec 4;258(5088):1654–1658. [PubMed]
  • Schleyer M, Bakker EP. Nucleotide sequence and 3'-end deletion studies indicate that the K(+)-uptake protein kup from Escherichia coli is composed of a hydrophobic core linked to a large and partially essential hydrophilic C terminus. J Bacteriol. 1993 Nov;175(21):6925–6931. [PMC free article] [PubMed]
  • Schroeder JI, Fang HH. Inward-rectifying K+ channels in guard cells provide a mechanism for low-affinity K+ uptake. Proc Natl Acad Sci U S A. 1991 Dec 15;88(24):11583–11587. [PMC free article] [PubMed]
  • Schroeder JI, Ward JM, Gassmann W. Perspectives on the physiology and structure of inward-rectifying K+ channels in higher plants: biophysical implications for K+ uptake. Annu Rev Biophys Biomol Struct. 1994;23:441–471. [PubMed]
  • Sentenac H, Bonneaud N, Minet M, Lacroute F, Salmon JM, Gaymard F, Grignon C. Cloning and expression in yeast of a plant potassium ion transport system. Science. 1992 May 1;256(5057):663–665. [PubMed]
  • Sherman F. Getting started with yeast. Methods Enzymol. 1991;194:3–21. [PubMed]
  • Smith FW, Ealing PM, Dong B, Delhaize E. The cloning of two Arabidopsis genes belonging to a phosphate transporter family. Plant J. 1997 Jan;11(1):83–92. [PubMed]
  • Villalba JM, Palmgren MG, Berberián GE, Ferguson C, Serrano R. Functional expression of plant plasma membrane H(+)-ATPase in yeast endoplasmic reticulum. J Biol Chem. 1992 Jun 15;267(17):12341–12349. [PubMed]
  • Walker NA, Sanders D, Maathuis FJ. High-affinity potassium uptake in plants. Science. 1996 Aug 16;273(5277):977–979. [PubMed]

Articles from The Plant Cell are provided here courtesy of American Society of Plant Biologists

Formats:

Related citations in PubMed

See reviews...See all...

Cited by other articles in PMC

See all...

Links

Recent Activity

Your browsing activity is empty.

Activity recording is turned off.

Turn recording back on

See more...