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. 1997 Jun 15;16(12):3455–3463. doi: 10.1093/emboj/16.12.3455

Tetramerization of the AKT1 plant potassium channel involves its C-terminal cytoplasmic domain.

P Daram 1, S Urbach 1, F Gaymard 1, H Sentenac 1, I Chérel 1
PMCID: PMC1169971  PMID: 9218788

Abstract

All plant channels identified so far show high conservation throughout the polypeptide sequence except in the ankyrin domain which is present only in those closely related to AKT1. In this study, the architecture of the AKT1 protein has been investigated. AKT1 polypeptides expressed in the baculovirus/Sf9 cells system were found to assemble into tetramers as observed with animal Shaker-like potassium channel subunits. The AKT1 C-terminal intracytoplasmic region (downstream from the transmembrane domain) alone formed tetrameric structures when expressed in Sf9 cells, revealing a tetramerization process different from that of Shaker channels. Tests of subfragments from this sequence in the two-hybrid system detected two kinds of interaction. The first, involving two identical segments (amino acids 371-516), would form a contact between subunits, probably via their putative cyclic nucleotide-binding domains. The second interaction was found between the last 81 amino acids of the protein and a region lying between the channel hydrophobic core and the putative cyclic nucleotide-binding domain. As the interacting regions are highly conserved in all known plant potassium channels, the structural organization of AKT1 is likely to extend to these channels. The significance of this model with respect to animal cyclic nucleotide-gated channels is also discussed.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Allen J. B., Walberg M. W., Edwards M. C., Elledge S. J. Finding prospective partners in the library: the two-hybrid system and phage display find a match. Trends Biochem Sci. 1995 Dec;20(12):511–516. doi: 10.1016/s0968-0004(00)89119-7. [DOI] [PubMed] [Google Scholar]
  2. Anderson J. A., Huprikar S. S., Kochian L. V., Lucas W. J., Gaber R. F. 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. doi: 10.1073/pnas.89.9.3736. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Attali B., Lesage F., Ziliani P., Guillemare E., Honoré E., Waldmann R., Hugnot J. P., Mattéi M. G., Lazdunski M., Barhanin J. Multiple mRNA isoforms encoding the mouse cardiac Kv1-5 delayed rectifier K+ channel. J Biol Chem. 1993 Nov 15;268(32):24283–24289. [PubMed] [Google Scholar]
  4. Basset M., Conejero G., Lepetit M., Fourcroy P., Sentenac H. Organization and expression of the gene coding for the potassium transport system AKT1 of Arabidopsis thaliana. Plant Mol Biol. 1995 Dec;29(5):947–958. doi: 10.1007/BF00014968. [DOI] [PubMed] [Google Scholar]
  5. Biel M., Zong X., Ludwig A., Sautter A., Hofmann F. Molecular cloning and expression of the Modulatory subunit of the cyclic nucleotide-gated cation channel. J Biol Chem. 1996 Mar 15;271(11):6349–6355. doi: 10.1074/jbc.271.11.6349. [DOI] [PubMed] [Google Scholar]
  6. Chen T. Y., Peng Y. W., Dhallan R. S., Ahamed B., Reed R. R., Yau K. W. A new subunit of the cyclic nucleotide-gated cation channel in retinal rods. Nature. 1993 Apr 22;362(6422):764–767. doi: 10.1038/362764a0. [DOI] [PubMed] [Google Scholar]
  7. Davrinche C., Pasquier C., Cerutti M., Serradell L., Clément D., Devauchelle G., Michelson S., Davignon J. L. Expression of human cytomegalovirus immediate early protein IE1 in insect cells: splicing of RNA and recognition by CD4+ T-cell clones. Biochem Biophys Res Commun. 1993 Aug 31;195(1):469–477. doi: 10.1006/bbrc.1993.2067. [DOI] [PubMed] [Google Scholar]
  8. Durfee T., Becherer K., Chen P. L., Yeh S. H., Yang Y., Kilburn A. E., Lee W. H., Elledge S. J. The retinoblastoma protein associates with the protein phosphatase type 1 catalytic subunit. Genes Dev. 1993 Apr;7(4):555–569. doi: 10.1101/gad.7.4.555. [DOI] [PubMed] [Google Scholar]
  9. Heusterspreute M., Ha Thi V., Emery S., Tournis-Gamble S., Kennedy N., Davison J. Vectors with restriction site banks. IV. pJRD184, a 3793-bp plasmid vector with 49 unique restriction sites. Gene. 1985;39(2-3):299–304. doi: 10.1016/0378-1119(85)90327-0. [DOI] [PubMed] [Google Scholar]
  10. Heyduk E., Heyduk T., Lee J. C. Intersubunit communications in Escherichia coli cyclic AMP receptor protein: studies of the ligand binding domain. Biochemistry. 1992 Apr 14;31(14):3682–3688. doi: 10.1021/bi00129a017. [DOI] [PubMed] [Google Scholar]
  11. Hoffman M. New role found for a common protein "motif". Science. 1991 Aug 16;253(5021):742–742. doi: 10.1126/science.1831563. [DOI] [PubMed] [Google Scholar]
  12. Hopkins W. F., Demas V., Tempel B. L. Both N- and C-terminal regions contribute to the assembly and functional expression of homo- and heteromultimeric voltage-gated K+ channels. J Neurosci. 1994 Mar;14(3 Pt 1):1385–1393. doi: 10.1523/JNEUROSCI.14-03-01385.1994. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Isacoff E. Y., Jan Y. N., Jan L. Y. Evidence for the formation of heteromultimeric potassium channels in Xenopus oocytes. Nature. 1990 Jun 7;345(6275):530–534. doi: 10.1038/345530a0. [DOI] [PubMed] [Google Scholar]
  14. Jan L. Y., Jan Y. N. Tracing the roots of ion channels. Cell. 1992 May 29;69(5):715–718. doi: 10.1016/0092-8674(92)90280-p. [DOI] [PubMed] [Google Scholar]
  15. Kaupp U. B., Niidome T., Tanabe T., Terada S., Bönigk W., Stühmer W., Cook N. J., Kangawa K., Matsuo H., Hirose T. Primary structure and functional expression from complementary DNA of the rod photoreceptor cyclic GMP-gated channel. Nature. 1989 Dec 14;342(6251):762–766. doi: 10.1038/342762a0. [DOI] [PubMed] [Google Scholar]
  16. Ketchum K. A., Slayman C. W. 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. doi: 10.1016/0014-5793(95)01417-9. [DOI] [PubMed] [Google Scholar]
  17. Kirsch G. E., Drewe J. A., De Biasi M., Hartmann H. A., Brown A. M. Functional interactions between K+ pore residues located in different subunits. J Biol Chem. 1993 Jul 5;268(19):13799–13804. [PubMed] [Google Scholar]
  18. Körschen H. G., Illing M., Seifert R., Sesti F., Williams A., Gotzes S., Colville C., Müller F., Dosé A., Godde M. A 240 kDa protein represents the complete beta subunit of the cyclic nucleotide-gated channel from rod photoreceptor. Neuron. 1995 Sep;15(3):627–636. doi: 10.1016/0896-6273(95)90151-5. [DOI] [PubMed] [Google Scholar]
  19. Lagarde D., Basset M., Lepetit M., Conejero G., Gaymard F., Astruc S., Grignon C. Tissue-specific expression of Arabidopsis AKT1 gene is consistent with a role in K+ nutrition. Plant J. 1996 Feb;9(2):195–203. doi: 10.1046/j.1365-313x.1996.09020195.x. [DOI] [PubMed] [Google Scholar]
  20. Lee T. E., Philipson L. H., Kuznetsov A., Nelson D. J. Structural determinant for assembly of mammalian K+ channels. Biophys J. 1994 Mar;66(3 Pt 1):667–673. doi: 10.1016/s0006-3495(94)80840-9. [DOI] [PMC free article] [PubMed] [Google Scholar]
  21. Li M., Jan Y. N., Jan L. Y. Specification of subunit assembly by the hydrophilic amino-terminal domain of the Shaker potassium channel. Science. 1992 Aug 28;257(5074):1225–1230. doi: 10.1126/science.1519059. [DOI] [PubMed] [Google Scholar]
  22. Li M., Unwin N., Stauffer K. A., Jan Y. N., Jan L. Y. Images of purified Shaker potassium channels. Curr Biol. 1994 Feb 1;4(2):110–115. doi: 10.1016/s0960-9822(94)00026-6. [DOI] [PubMed] [Google Scholar]
  23. Liman E. R., Tytgat J., Hess P. Subunit stoichiometry of a mammalian K+ channel determined by construction of multimeric cDNAs. Neuron. 1992 Nov;9(5):861–871. doi: 10.1016/0896-6273(92)90239-a. [DOI] [PubMed] [Google Scholar]
  24. Liu D. T., Tibbs G. R., Siegelbaum S. A. Subunit stoichiometry of cyclic nucleotide-gated channels and effects of subunit order on channel function. Neuron. 1996 May;16(5):983–990. doi: 10.1016/s0896-6273(00)80121-x. [DOI] [PubMed] [Google Scholar]
  25. MacKinnon R. Determination of the subunit stoichiometry of a voltage-activated potassium channel. Nature. 1991 Mar 21;350(6315):232–235. doi: 10.1038/350232a0. [DOI] [PubMed] [Google Scholar]
  26. Müller-Röber B., Ellenberg J., Provart N., Willmitzer L., Busch H., Becker D., Dietrich P., Hoth S., Hedrich R. Cloning and electrophysiological analysis of KST1, an inward rectifying K+ channel expressed in potato guard cells. EMBO J. 1995 Jun 1;14(11):2409–2416. doi: 10.1002/j.1460-2075.1995.tb07238.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  27. Pearson W. R., Lipman D. J. Improved tools for biological sequence comparison. Proc Natl Acad Sci U S A. 1988 Apr;85(8):2444–2448. doi: 10.1073/pnas.85.8.2444. [DOI] [PMC free article] [PubMed] [Google Scholar]
  28. Pfaffinger P. J., DeRubeis D. Shaker K+ channel T1 domain self-tetramerizes to a stable structure. J Biol Chem. 1995 Dec 1;270(48):28595–28600. doi: 10.1074/jbc.270.48.28595. [DOI] [PubMed] [Google Scholar]
  29. Ruppersberg J. P., Schröter K. H., Sakmann B., Stocker M., Sewing S., Pongs O. Heteromultimeric channels formed by rat brain potassium-channel proteins. Nature. 1990 Jun 7;345(6275):535–537. doi: 10.1038/345535a0. [DOI] [PubMed] [Google Scholar]
  30. Sentenac H., Bonneaud N., Minet M., Lacroute F., Salmon J. M., Gaymard F., Grignon C. Cloning and expression in yeast of a plant potassium ion transport system. Science. 1992 May 1;256(5057):663–665. doi: 10.1126/science.1585180. [DOI] [PubMed] [Google Scholar]
  31. Shabb J. B., Poteet C. E., Kapphahn M. A., Muhonen W. M., Baker N. E., Corbin J. D. Characterization of the isolated cAMP-binding B domain of cAMP-dependent protein kinase. Protein Sci. 1995 Oct;4(10):2100–2106. doi: 10.1002/pro.5560041015. [DOI] [PMC free article] [PubMed] [Google Scholar]
  32. Shen N. V., Chen X., Boyer M. M., Pfaffinger P. J. Deletion analysis of K+ channel assembly. Neuron. 1993 Jul;11(1):67–76. doi: 10.1016/0896-6273(93)90271-r. [DOI] [PubMed] [Google Scholar]
  33. Shen N. V., Pfaffinger P. J. Molecular recognition and assembly sequences involved in the subfamily-specific assembly of voltage-gated K+ channel subunit proteins. Neuron. 1995 Mar;14(3):625–633. doi: 10.1016/0896-6273(95)90319-4. [DOI] [PubMed] [Google Scholar]
  34. Sherman F. Getting started with yeast. Methods Enzymol. 1991;194:3–21. doi: 10.1016/0076-6879(91)94004-v. [DOI] [PubMed] [Google Scholar]
  35. Tu L., Santarelli V., Deutsch C. Truncated K+ channel DNA sequences specifically suppress lymphocyte K+ channel gene expression. Biophys J. 1995 Jan;68(1):147–156. doi: 10.1016/S0006-3495(95)80169-4. [DOI] [PMC free article] [PubMed] [Google Scholar]
  36. Tu L., Santarelli V., Sheng Z., Skach W., Pain D., Deutsch C. Voltage-gated K+ channels contain multiple intersubunit association sites. J Biol Chem. 1996 Aug 2;271(31):18904–18911. doi: 10.1074/jbc.271.31.18904. [DOI] [PubMed] [Google Scholar]
  37. VanDongen A. M., Frech G. C., Drewe J. A., Joho R. H., Brown A. M. Alteration and restoration of K+ channel function by deletions at the N- and C-termini. Neuron. 1990 Oct;5(4):433–443. doi: 10.1016/0896-6273(90)90082-q. [DOI] [PubMed] [Google Scholar]
  38. Weber I. T., Steitz T. A., Bubis J., Taylor S. S. Predicted structures of cAMP binding domains of type I and II regulatory subunits of cAMP-dependent protein kinase. Biochemistry. 1987 Jan 27;26(2):343–351. doi: 10.1021/bi00376a003. [DOI] [PubMed] [Google Scholar]
  39. Weber I. T., Steitz T. A. Model of specific complex between catabolite gene activator protein and B-DNA suggested by electrostatic complementarity. Proc Natl Acad Sci U S A. 1984 Jul;81(13):3973–3977. doi: 10.1073/pnas.81.13.3973. [DOI] [PMC free article] [PubMed] [Google Scholar]
  40. Werner M., Chaussivert N., Willis I. M., Sentenac A. Interaction between a complex of RNA polymerase III subunits and the 70-kDa component of transcription factor IIIB. J Biol Chem. 1993 Oct 5;268(28):20721–20724. [PubMed] [Google Scholar]
  41. Wes P. D., Chevesich J., Jeromin A., Rosenberg C., Stetten G., Montell C. TRPC1, a human homolog of a Drosophila store-operated channel. Proc Natl Acad Sci U S A. 1995 Oct 10;92(21):9652–9656. doi: 10.1073/pnas.92.21.9652. [DOI] [PMC free article] [PubMed] [Google Scholar]
  42. Xu J., Yu W., Jan Y. N., Jan L. Y., Li M. Assembly of voltage-gated potassium channels. Conserved hydrophilic motifs determine subfamily-specific interactions between the alpha-subunits. J Biol Chem. 1995 Oct 20;270(42):24761–24768. doi: 10.1074/jbc.270.42.24761. [DOI] [PubMed] [Google Scholar]
  43. Zufall F., Firestein S., Shepherd G. M. Cyclic nucleotide-gated ion channels and sensory transduction in olfactory receptor neurons. Annu Rev Biophys Biomol Struct. 1994;23:577–607. doi: 10.1146/annurev.bb.23.060194.003045. [DOI] [PubMed] [Google Scholar]

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