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. 1995 Jul 18;92(15):7115–7119. doi: 10.1073/pnas.92.15.7115

Convergent and parallel activation of low-conductance potassium channels by calcium and cAMP-dependent protein kinase.

S D Lidofsky 1
PMCID: PMC41482  PMID: 7624380

Abstract

K+ channels, which have been linked to regulation of electrogenic solute transport as well as Ca2+ influx, represent a locus in hepatocytes for the concerted actions of hormones that employ Ca2+ and cAMP as intracellular messengers. Despite considerable study, the single-channel basis for synergistic effects of Ca2+ and cAMP on hepatocellular K+ conductance is not well understood. To address this question, patch-clamp recording techniques were applied to a model liver cell line, HTC hepatoma cells. Increasing the cytosolic Ca2+ concentration ([Ca2+]i) in HTC cells, either by activation of purinergic receptors with ATP or by inhibition of intracellular Ca2+ sequestration with thapsigargin, activated low-conductance (9-pS) K+ channels. Studies with excised membrane patches suggested that these channels were directly activated by Ca2+. Exposure of HTC cells to a permeant cAMP analog, 8-(4-chlorophenylthio)-cAMP, also activated 9-pS K+ channels but did not change [Ca2+]i. In excised membrane patches, cAMP-dependent protein kinase (the downstream effector of cAMP) activated K+ channels with conductance and selectivity identical to those of channels activated by Ca2+. In addition, cAMP-dependent protein kinase activated a distinct K+ channel type (5 pS). These data represent the differential regulation of low-conductance K+ channels by signaling pathways mediated by Ca2+ and cAMP. Moreover, since low-conductance Ca(2+)-activated K+ channels have been identified in a variety of cell types, these findings suggest that differential regulation of K+ channels by hormones with distinct signaling pathways may provide a mechanism for hormonal control of solute transport and Ca(2+)-dependent cellular functions in the liver as well as other nonexcitable tissues.

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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 M. L., Metz A. M., Timmer R. T., Rhoads R. E., Browning K. S. Isolation and sequence of the cDNAs encoding the subunits of the isozyme form of wheat protein synthesis initiation factor 4F. J Biol Chem. 1992 Nov 15;267(32):23232–23236. [PubMed] [Google Scholar]
  2. Altin J. G., Biden T. J., Karjalainen A., Bygrave F. L. Exposure to depolarizing concentrations of K+ inhibits hormonally-induced calcium influx in rat liver. Biochem Biophys Res Commun. 1988 Jun 30;153(3):1282–1289. doi: 10.1016/s0006-291x(88)81367-6. [DOI] [PubMed] [Google Scholar]
  3. Ammälä C., Ashcroft F. M., Rorsman P. Calcium-independent potentiation of insulin release by cyclic AMP in single beta-cells. Nature. 1993 May 27;363(6427):356–358. doi: 10.1038/363356a0. [DOI] [PubMed] [Google Scholar]
  4. Artalejo A. R., García A. G., Neher E. Small-conductance Ca(2+)-activated K+ channels in bovine chromaffin cells. Pflugers Arch. 1993 Apr;423(1-2):97–103. doi: 10.1007/BF00374966. [DOI] [PubMed] [Google Scholar]
  5. Bloom G. S., Luca F. C., Vallee R. B. Microtubule-associated protein 1B: identification of a major component of the neuronal cytoskeleton. Proc Natl Acad Sci U S A. 1985 Aug;82(16):5404–5408. doi: 10.1073/pnas.82.16.5404. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Blose S. H., Meltzer D. I., Feramisco J. R. 10-nm filaments are induced to collapse in living cells microinjected with monoclonal and polyclonal antibodies against tubulin. J Cell Biol. 1984 Mar;98(3):847–858. doi: 10.1083/jcb.98.3.847. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Bokros C. L., Hugdahl J. D., Hanesworth V. R., Murthy J. V., Morejohn L. C. Characterization of the reversible taxol-induced polymerization of plant tubulin into microtubules. Biochemistry. 1993 Apr 6;32(13):3437–3447. doi: 10.1021/bi00064a030. [DOI] [PubMed] [Google Scholar]
  8. Bradford M. M. A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding. Anal Biochem. 1976 May 7;72:248–254. doi: 10.1016/0003-2697(76)90527-3. [DOI] [PubMed] [Google Scholar]
  9. Browning K. S., Humphreys J., Hobbs W., Smith G. B., Ravel J. M. Determination of the amounts of the protein synthesis initiation and elongation factors in wheat germ. J Biol Chem. 1990 Oct 15;265(29):17967–17973. [PubMed] [Google Scholar]
  10. Browning K. S., Webster C., Roberts J. K., Ravel J. M. Identification of an isozyme form of protein synthesis initiation factor 4F in plants. J Biol Chem. 1992 May 15;267(14):10096–10100. [PubMed] [Google Scholar]
  11. Burgess G. M., Bird G. S., Obie J. F., Putney J. W., Jr The mechanism for synergism between phospholipase C- and adenylylcyclase-linked hormones in liver. Cyclic AMP-dependent kinase augments inositol trisphosphate-mediated Ca2+ mobilization without increasing the cellular levels of inositol polyphosphates. J Biol Chem. 1991 Mar 15;266(8):4772–4781. [PubMed] [Google Scholar]
  12. Capiod T., Ogden D. C. Properties of membrane ion conductances evoked by hormonal stimulation of guinea-pig and rabbit isolated hepatocytes. Proc R Soc Lond B Biol Sci. 1989 Mar 22;236(1283):187–201. doi: 10.1098/rspb.1989.0020. [DOI] [PubMed] [Google Scholar]
  13. Capiod T., Ogden D. C. The properties of calcium-activated potassium ion channels in guinea-pig isolated hepatocytes. J Physiol. 1989 Feb;409:285–295. doi: 10.1113/jphysiol.1989.sp017497. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Carl A., Kenyon J. L., Uemura D., Fusetani N., Sanders K. M. Regulation of Ca(2+)-activated K+ channels by protein kinase A and phosphatase inhibitors. Am J Physiol. 1991 Aug;261(2 Pt 1):C387–C392. doi: 10.1152/ajpcell.1991.261.2.C387. [DOI] [PubMed] [Google Scholar]
  15. Cervera M., Dreyfuss G., Penman S. Messenger RNA is translated when associated with the cytoskeletal framework in normal and VSV-infected HeLa cells. Cell. 1981 Jan;23(1):113–120. doi: 10.1016/0092-8674(81)90276-2. [DOI] [PubMed] [Google Scholar]
  16. Christensen O., Hoffmann E. K. Cell swelling activates K+ and Cl- channels as well as nonselective, stretch-activated cation channels in Ehrlich ascites tumor cells. J Membr Biol. 1992 Jul;129(1):13–36. doi: 10.1007/BF00232052. [DOI] [PubMed] [Google Scholar]
  17. Cliff W. H., Frizzell R. A. Separate Cl- conductances activated by cAMP and Ca2+ in Cl(-)-secreting epithelial cells. Proc Natl Acad Sci U S A. 1990 Jul;87(13):4956–4960. doi: 10.1073/pnas.87.13.4956. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Cocks T. M., Jenkinson D. H., Koller K. Interactions between receptors that increase cytosolic calcium and cyclic AMP in guinea-pig liver cells. Br J Pharmacol. 1984 Sep;83(1):281–291. doi: 10.1111/j.1476-5381.1984.tb10144.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Esguerra M., Wang J., Foster C. D., Adelman J. P., North R. A., Levitan I. B. Cloned Ca(2+)-dependent K+ channel modulated by a functionally associated protein kinase. Nature. 1994 Jun 16;369(6481):563–565. doi: 10.1038/369563a0. [DOI] [PubMed] [Google Scholar]
  20. Fitz J. G., Lidofsky S. D., Xie M. H., Scharschmidt B. F. Transmembrane electrical potential difference regulates Na+/HCO3- cotransport and intracellular pH in hepatocytes. Proc Natl Acad Sci U S A. 1992 May 1;89(9):4197–4201. doi: 10.1073/pnas.89.9.4197. [DOI] [PMC free article] [PubMed] [Google Scholar]
  21. Fitz J. G., Sostman A. H., Middleton J. P. Regulation of cation channels in liver cells by intracellular calcium and protein kinase C. Am J Physiol. 1994 Apr;266(4 Pt 1):G677–G684. doi: 10.1152/ajpgi.1994.266.4.G677. [DOI] [PubMed] [Google Scholar]
  22. Fitz J. G., Sostman A. H. Nucleotide receptors activate cation, potassium, and chloride currents in a liver cell line. Am J Physiol. 1994 Apr;266(4 Pt 1):G544–G553. doi: 10.1152/ajpgi.1994.266.4.G544. [DOI] [PubMed] [Google Scholar]
  23. Fulton A. B., Wan K. M. Many cytoskeletal proteins associate with the hela cytoskeleton during translation in vitro. Cell. 1983 Feb;32(2):619–625. doi: 10.1016/0092-8674(83)90481-6. [DOI] [PubMed] [Google Scholar]
  24. Föhr K. J., Warchol W., Gratzl M. Calculation and control of free divalent cations in solutions used for membrane fusion studies. Methods Enzymol. 1993;221:149–157. doi: 10.1016/0076-6879(93)21014-y. [DOI] [PubMed] [Google Scholar]
  25. Goodson H. V., Kang S. J., Endow S. A. Molecular phylogeny of the kinesin family of microtubule motor proteins. J Cell Sci. 1994 Jul;107(Pt 7):1875–1884. doi: 10.1242/jcs.107.7.1875. [DOI] [PubMed] [Google Scholar]
  26. Graf J., Henderson R. M., Krumpholz B., Boyer J. L. Cell membrane and transepithelial voltages and resistances in isolated rat hepatocyte couplets. J Membr Biol. 1987;95(3):241–254. doi: 10.1007/BF01869486. [DOI] [PubMed] [Google Scholar]
  27. Gray M. A., Greenwell J. R., Garton A. J., Argent B. E. Regulation of maxi-K+ channels on pancreatic duct cells by cyclic AMP-dependent phosphorylation. J Membr Biol. 1990 May;115(3):203–215. doi: 10.1007/BF01868636. [DOI] [PubMed] [Google Scholar]
  28. Groschner K., Graier W. F., Kukovetz W. R. Activation of a small-conductance Ca(2+)-dependent K+ channel contributes to bradykinin-induced stimulation of nitric oxide synthesis in pig aortic endothelial cells. Biochim Biophys Acta. 1992 Oct 27;1137(2):162–170. doi: 10.1016/0167-4889(92)90198-k. [DOI] [PubMed] [Google Scholar]
  29. Hamill D., Davis J., Drawbridge J., Suprenant K. A. Polyribosome targeting to microtubules: enrichment of specific mRNAs in a reconstituted microtubule preparation from sea urchin embryos. J Cell Biol. 1994 Nov;127(4):973–984. doi: 10.1083/jcb.127.4.973. [DOI] [PMC free article] [PubMed] [Google Scholar]
  30. Hawley D. M., Maddux B. A., Patel R. G., Wong K. Y., Mamula P. W., Firestone G. L., Brunetti A., Verspohl E., Goldfine I. D. Insulin receptor monoclonal antibodies that mimic insulin action without activating tyrosine kinase. J Biol Chem. 1989 Feb 15;264(5):2438–2444. [PubMed] [Google Scholar]
  31. Henderson R. M., Graf J., Boyer J. L. Inward-rectifying potassium channels in rat hepatocytes. Am J Physiol. 1989 Jun;256(6 Pt 1):G1028–G1035. doi: 10.1152/ajpgi.1989.256.6.G1028. [DOI] [PubMed] [Google Scholar]
  32. Hill C. E., Ajikobi D. O. Inhibition of alpha-adrenergic responses in the rat liver by lipophilic K+ channel blockers or depolarizing Cl- gradients. Evidence for a potential-sensitive step in the signal transduction path. Biochem Cell Biol. 1993 May-Jun;71(5-6):229–235. doi: 10.1139/o93-035. [DOI] [PubMed] [Google Scholar]
  33. Howe J. G., Hershey J. W. Translational initiation factor and ribosome association with the cytoskeletal framework fraction from HeLa cells. Cell. 1984 May;37(1):85–93. doi: 10.1016/0092-8674(84)90303-9. [DOI] [PubMed] [Google Scholar]
  34. Hugdahl J. D., Bokros C. L., Hanesworth V. R., Aalund G. R., Morejohn L. C. Unique functional characteristics of the polymerization and MAP binding regulatory domains of plant tubulin. Plant Cell. 1993 Sep;5(9):1063–1080. doi: 10.1105/tpc.5.9.1063. [DOI] [PMC free article] [PubMed] [Google Scholar]
  35. Hugdahl J. D., Morejohn L. C. Deficient nucleation during co-polymerization of mammalian MAP2 and tobacco tubulin. Biochem Mol Biol Int. 1994 Sep;34(2):375–384. [PubMed] [Google Scholar]
  36. Kass G. E., Llopis J., Chow S. C., Duddy S. K., Orrenius S. Receptor-operated calcium influx in rat hepatocytes. Identification and characterization using manganese. J Biol Chem. 1990 Oct 15;265(29):17486–17492. [PubMed] [Google Scholar]
  37. Kume H., Takai A., Tokuno H., Tomita T. Regulation of Ca2+-dependent K+-channel activity in tracheal myocytes by phosphorylation. Nature. 1989 Sep 14;341(6238):152–154. doi: 10.1038/341152a0. [DOI] [PubMed] [Google Scholar]
  38. Kuriyama R., Savereide P., Lefebvre P., Dasgupta S. The predicted amino acid sequence of a centrosphere protein in dividing sea urchin eggs is similar to elongation factor (EF-1 alpha). J Cell Sci. 1990 Feb;95(Pt 2):231–236. doi: 10.1242/jcs.95.2.231. [DOI] [PubMed] [Google Scholar]
  39. Kyhse-Andersen J. Electroblotting of multiple gels: a simple apparatus without buffer tank for rapid transfer of proteins from polyacrylamide to nitrocellulose. J Biochem Biophys Methods. 1984 Dec;10(3-4):203–209. doi: 10.1016/0165-022x(84)90040-x. [DOI] [PubMed] [Google Scholar]
  40. Laemmli U. K. Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature. 1970 Aug 15;227(5259):680–685. doi: 10.1038/227680a0. [DOI] [PubMed] [Google Scholar]
  41. Latorre R., Oberhauser A., Labarca P., Alvarez O. Varieties of calcium-activated potassium channels. Annu Rev Physiol. 1989;51:385–399. doi: 10.1146/annurev.ph.51.030189.002125. [DOI] [PubMed] [Google Scholar]
  42. Lax S. R., Browning K. S., Maia D. M., Ravel J. M. ATPase activities of wheat germ initiation factors 4A, 4B, and 4F. J Biol Chem. 1986 Nov 25;261(33):15632–15636. [PubMed] [Google Scholar]
  43. Lenk R., Ransom L., Kaufmann Y., Penman S. A cytoskeletal structure with associated polyribosomes obtained from HeLa cells. Cell. 1977 Jan;10(1):67–78. doi: 10.1016/0092-8674(77)90141-6. [DOI] [PubMed] [Google Scholar]
  44. Lidofsky S. D., Fitz J. G., Weisiger R. A., Scharschmidt B. F. Hepatic taurocholate uptake is electrogenic and influenced by transmembrane potential difference. Am J Physiol. 1993 Mar;264(3 Pt 1):G478–G485. doi: 10.1152/ajpgi.1993.264.3.G478. [DOI] [PubMed] [Google Scholar]
  45. Marchesi V. T., Ngo N. In vitro assembly of multiprotein complexes containing alpha, beta, and gamma tubulin, heat shock protein HSP70, and elongation factor 1 alpha. Proc Natl Acad Sci U S A. 1993 Apr 1;90(7):3028–3032. doi: 10.1073/pnas.90.7.3028. [DOI] [PMC free article] [PubMed] [Google Scholar]
  46. McCann J. D., Matsuda J., Garcia M., Kaczorowski G., Welsh M. J. Basolateral K+ channels in airway epithelia. I. Regulation by Ca2+ and block by charybdotoxin. Am J Physiol. 1990 Jun;258(6 Pt 1):L334–L342. doi: 10.1152/ajplung.1990.258.6.L334. [DOI] [PubMed] [Google Scholar]
  47. McKinney J. S., Desole M. S., Rubin R. P. Convergence of cAMP and phosphoinositide pathways during rat parotid secretion. Am J Physiol. 1989 Oct;257(4 Pt 1):C651–C657. doi: 10.1152/ajpcell.1989.257.4.C651. [DOI] [PubMed] [Google Scholar]
  48. Mitsui H., Yamaguchi-Shinozaki K., Shinozaki K., Nishikawa K., Takahashi H. Identification of a gene family (kat) encoding kinesin-like proteins in Arabidopsis thaliana and the characterization of secondary structure of KatA. Mol Gen Genet. 1993 Apr;238(3):362–368. doi: 10.1007/BF00291995. [DOI] [PubMed] [Google Scholar]
  49. Morejohn L. C., Bureau T. E., Tocchi L. P., Fosket D. E. Tubulins from different higher plant species are immunologically nonidentical and bind colchicine differentially. Proc Natl Acad Sci U S A. 1984 Mar;81(5):1440–1444. doi: 10.1073/pnas.81.5.1440. [DOI] [PMC free article] [PubMed] [Google Scholar]
  50. Morejohn L. C., Fosket D. E. Higher plant tubulin identified by self-assembly into microtubules in vitro. Nature. 1982 Jun 3;297(5865):426–428. doi: 10.1038/297426a0. [DOI] [PubMed] [Google Scholar]
  51. Morgan N. G., Charest R., Blackmore P. F., Exton J. H. Potentiation of alpha 1-adrenergic responses in rat liver by a cAMP-dependent mechanism. Proc Natl Acad Sci U S A. 1984 Jul;81(13):4208–4212. doi: 10.1073/pnas.81.13.4208. [DOI] [PMC free article] [PubMed] [Google Scholar]
  52. Negrutskii B. S., Stapulionis R., Deutscher M. P. Supramolecular organization of the mammalian translation system. Proc Natl Acad Sci U S A. 1994 Feb 1;91(3):964–968. doi: 10.1073/pnas.91.3.964. [DOI] [PMC free article] [PubMed] [Google Scholar]
  53. Ohta K., Toriyama M., Miyazaki M., Murofushi H., Hosoda S., Endo S., Sakai H. The mitotic apparatus-associated 51-kDa protein from sea urchin eggs is a GTP-binding protein and is immunologically related to yeast polypeptide elongation factor 1 alpha. J Biol Chem. 1990 Feb 25;265(6):3240–3247. [PubMed] [Google Scholar]
  54. Ornelles D. A., Fey E. G., Penman S. Cytochalasin releases mRNA from the cytoskeletal framework and inhibits protein synthesis. Mol Cell Biol. 1986 May;6(5):1650–1662. doi: 10.1128/mcb.6.5.1650. [DOI] [PMC free article] [PubMed] [Google Scholar]
  55. Papasozomenos S. C., Binder L. I. Phosphorylation determines two distinct species of Tau in the central nervous system. Cell Motil Cytoskeleton. 1987;8(3):210–226. doi: 10.1002/cm.970080303. [DOI] [PubMed] [Google Scholar]
  56. Penner R., Matthews G., Neher E. Regulation of calcium influx by second messengers in rat mast cells. Nature. 1988 Aug 11;334(6182):499–504. doi: 10.1038/334499a0. [DOI] [PubMed] [Google Scholar]
  57. Pfister K. K., Wagner M. C., Stenoien D. L., Brady S. T., Bloom G. S. Monoclonal antibodies to kinesin heavy and light chains stain vesicle-like structures, but not microtubules, in cultured cells. J Cell Biol. 1989 Apr;108(4):1453–1463. doi: 10.1083/jcb.108.4.1453. [DOI] [PMC free article] [PubMed] [Google Scholar]
  58. Poggioli J., Mauger J. P., Claret M. Effect of cyclic AMP-dependent hormones and Ca2+-mobilizing hormones on the Ca2+ influx and polyphosphoinositide metabolism in isolated rat hepatocytes. Biochem J. 1986 May 1;235(3):663–669. doi: 10.1042/bj2350663. [DOI] [PMC free article] [PubMed] [Google Scholar]
  59. Root D. D., Wang K. Silver-enhanced copper staining of protein blots. Anal Biochem. 1993 Feb 15;209(1):15–19. doi: 10.1006/abio.1993.1077. [DOI] [PubMed] [Google Scholar]
  60. Savage A. L., Biffen M., Martin B. R. Vasopressin-stimulated Ca2+ influx in rat hepatocytes is inhibited in high-K+ medium. Biochem J. 1989 Jun 15;260(3):821–827. doi: 10.1042/bj2600821. [DOI] [PMC free article] [PubMed] [Google Scholar]
  61. Shestakova E. A., Motuz L. P., Gavrilova L. P. Co-localization of components of the protein-synthesizing machinery with the cytoskeleton in G0-arrested cells. Cell Biol Int. 1993 Apr;17(4):417–424. doi: 10.1006/cbir.1993.1080. [DOI] [PubMed] [Google Scholar]
  62. Shestakova E. A., Motuz L. P., Minin A. A., Gavrilova L. P. Study of localization of the protein-synthesizing machinery along actin filament bundles. Cell Biol Int. 1993 Apr;17(4):409–416. doi: 10.1006/cbir.1993.1079. [DOI] [PubMed] [Google Scholar]
  63. Shiina N., Gotoh Y., Kubomura N., Iwamatsu A., Nishida E. Microtubule severing by elongation factor 1 alpha. Science. 1994 Oct 14;266(5183):282–285. doi: 10.1126/science.7939665. [DOI] [PubMed] [Google Scholar]
  64. Suprenant K. A., Tempero L. B., Hammer L. E. Association of ribosomes with in vitro assembled microtubules. Cell Motil Cytoskeleton. 1989;14(3):401–415. doi: 10.1002/cm.970140310. [DOI] [PubMed] [Google Scholar]
  65. Toriyama M., Ohta K., Endo S., Sakai H. 51-kd protein, a component of microtubule-organizing granules in the mitotic apparatus involved in aster formation in vitro. Cell Motil Cytoskeleton. 1988;9(2):117–128. doi: 10.1002/cm.970090204. [DOI] [PubMed] [Google Scholar]
  66. Wiche G., Oberkanins C., Himmler A. Molecular structure and function of microtubule-associated proteins. Int Rev Cytol. 1991;124:217–273. doi: 10.1016/s0074-7696(08)61528-4. [DOI] [PubMed] [Google Scholar]
  67. Wondergem R., Castillo L. B. Quinine decreases hepatocyte transmembrane potential and inhibits amino acid transport. Am J Physiol. 1988 Jun;254(6 Pt 1):G795–G801. doi: 10.1152/ajpgi.1988.254.6.G795. [DOI] [PubMed] [Google Scholar]
  68. Yang J. T., Laymon R. A., Goldstein L. S. A three-domain structure of kinesin heavy chain revealed by DNA sequence and microtubule binding analyses. Cell. 1989 Mar 10;56(5):879–889. doi: 10.1016/0092-8674(89)90692-2. [DOI] [PubMed] [Google Scholar]
  69. You W., Abe S., Davies E. Cosedimentation of pea root polysomes with the cytoskeleton. Cell Biol Int Rep. 1992 Jul;16(7):663–673. doi: 10.1016/s0309-1651(06)80008-1. [DOI] [PubMed] [Google Scholar]
  70. van Heerden A., Browning K. S. Expression in Escherichia coli of the two subunits of the isozyme form of wheat germ protein synthesis initiation factor 4F. Purification of the subunits and formation of an enzymatically active complex. J Biol Chem. 1994 Jul 1;269(26):17454–17457. [PubMed] [Google Scholar]

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