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Direct activation of inward rectifier potassium channels by PIP2 and its stabilization by Gβγ

Abstract

Inward rectifier K+ channels, which modulate electrical activity in many cell types, are regulated by protein kinases1,2, guanine-nucleotide-binding proteins (G proteins)3,4,5,6 and probably actin cytoskeleton7. Generation of phosphatidylinositol 4,5-bisphosphate (PIP2) by ATP-dependent lipid kinases is known to activate inward rectifier K+ channels in cardiac membrane patches8. Herewe report that several cloned inward rectifier K+ channels directly bind PIP2, and that this binding correlates with channel activity. Application of ATP or PIP2 liposomes activates the cloned channels. Stabilized by lipid phosphatase inhibitors, PIP2 antibodies9 potently inhibit each channel with a unique rate (GIRK1/4 (3-5) ≈ GIRK2 (ref. 6) IRK1 (ref. 10) ≈ ROMK (ref. 11)). Consistent with the faster dissociation of PIP2 from the GIRK channels, the carboxy terminus of GIRK1 binds 3H-PIP2 liposomes more weakly than does that of IRK1 or ROMK1. Mutation of a conserved arginine to glutamine at position 188 reduces the ability of ROMK1 to bind PIP2 and increases its sensitivity to inhibition by PIP2 antibodies. Interactions between GIRK channels and PIP2 are modulated by the βγ subunits of the G protein (Gβγ). When GIRK1/4 channels are allowed to run down completely, they are not activated by addition of Gβγ alone, but application of PIP2 activates them in minutes without Gβγ and in just seconds with Gβγ. Finally, coexpression of Gβγ with GIRK channels slows the inhibition of K+ currents by PIP2 antibodies by more than 10-fold. Thus Gβγ activates GIRK channels by stabilizing interactions between PIP2 and the K+ channel.

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Figure 1: PIP2 dependence of cloned inward rectifier K+ channels.
Figure 2: Direct binding of PIP2 with inward rectifier K+ channels.
Figure 3: a, Amino-acid alignment for the proximal C-terminal regions of the inward rectifier K+ channels.
Figure 4: Gβγ-induced sensitization of GIRK1/4 channels to activation by PIP2.

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References

  1. McNicholas, C. M., Wang, W., Ho, K., Hebert, S. C. & Giebisch, G. Regulation of ROMK1 K+ channel activity involves phosphorylation processes. Proc. Natl Acad. Sci. USA 91, 8077–8081 (1994).

    Article  ADS  CAS  Google Scholar 

  2. Fakler, B., Brandle, U., Glowatzki, E., Zenner, H.-P. & Ruppersberg, J. P. Kir2.1 inward rectifier K+ channels are regulated independently by protein kinases and ATP hydrolysis. Neuron 13, 1413–1420 (1994).

    Article  CAS  Google Scholar 

  3. Kubo, Y., Reuveny, E., Slesinger, P. A., Jan, Y. N. & Jan, L. Y. Primary structure and functional expression of a rat G-protein-coupled muscarinic potassium channel. Nature 364, 802–806 (1993).

    Article  ADS  CAS  Google Scholar 

  4. Dascal, N. et al. Atrial G protein-activated K+ channel: expression cloning and molecular properties. Proc. Natl Acad. Sci. USA 90, 10235–10239 (1993).

    Article  ADS  CAS  Google Scholar 

  5. Krapivinsky, G. et al. The G-protein-gated atrial K+ channel IKAChis a heteromultimer of two inwardly rectifying K+-channel proteins. Nature 374, 135–141 (1995).

    Article  ADS  CAS  Google Scholar 

  6. Lesage, F. et al. Molecular properties of neuronal G protein-activated inwardly rectifying K+ channels. J. Biol. Chem. 270, 28660–28667 (1995).

    Article  CAS  Google Scholar 

  7. Furukawa, T., Yamane, T., Terai, T., Katayama, Y. & Hiraoka, M. Functional linkage of the cardiac ATP-sensitive K+ channel to actin cytoskeleton. Pflugers Arch. 431, 504–512 (1996).

    Article  CAS  Google Scholar 

  8. Hilgemann, D. W. & Ball, R. Regulationof cardiac Na+, Ca2+ exchange and KATPpotassium channels by PIP2. Science 273, 956–959 (1996).

    Article  ADS  CAS  Google Scholar 

  9. Fukami, K. et al. Antibody to phosphatidylinositol 4,5-bisphosphate inhibits oncogene-induced mitogenesis. Proc. Natl Acad. Sci. USA 85, 9057–9061 (1988).

    Article  ADS  CAS  Google Scholar 

  10. Kubo, Y., Baldwin, T. J., Jan, Y. N. & Jan, L. Y. Primary structure and functional expression of a mouse inward rectifier potassium channel. Nature 362, 127–133 (1993).

    Article  ADS  CAS  Google Scholar 

  11. Ho, K. et al. Cloning and expression of an inwardly rectifying ATP-regulated potassium channel. Nature 362, 31–38 (1993).

    Article  ADS  CAS  Google Scholar 

  12. Sui, J. L., Chan, K. W. & Logothetis, D. E. Na+ activation of the muscarinic K+ channel by a G-protein-independent mechanism. J. Gen. Physiol. 109, 381–390 (1996).

    Article  Google Scholar 

  13. Chan, K. W. et al. Arecombinant inwardly rectifying potassium channel coupled to GTP-binding proteins. J. Gen. Physiol. 107, 381–397 (1996).

    Article  CAS  Google Scholar 

  14. Zhang, X., Jefferson, A. B., Auethavekiat, V. & Majerus, P. W. The protein deficient in Lowe syndrome is a phosphatidylinositol-4,5-bisphosphate 5-phosphatase. Proc. Natl Acad. Sci. USA 92, 4853–4856 (1995).

    Article  ADS  CAS  Google Scholar 

  15. Fukami, K., Endo, T., Imamura, M. & Takenawa, T. α-Actinin and vinculin are PIP2-binding proteins involved in signaling by tyrosine kinase. J. Biol. Chem. 269, 1518–1522 (1994).

    CAS  PubMed  Google Scholar 

  16. Fan, Z. & Makielski, J. C. Anionic phospholipids activate ATP-sensitive potassium channels. J. Biol. Chem. 272, 5388–5395 (1997).

    Article  CAS  Google Scholar 

  17. Schacht, J. Inhibition by neomycin of polyphosphoinositide turnover in subcellular fractions of guinea-pig cerebral cortex in vitro. J. Neurochem. 27, 1119–1124 (1976).

    Article  CAS  Google Scholar 

  18. Kim, J., Mosior, M., Chung, L. A., Wu, H. & McLaughlin, S. Binding of peptides with basic residues to membrane containing acidic phospholipids. Biophys. J. 60, 135–148 (1991).

    Article  CAS  Google Scholar 

  19. Harlan, J. E., Yoon, H. S., Hajduk, P. J. & Fesik, S. W. Structural characterization of the interaction between a pleckstrin homology domain and phosphatidylinositol 4,5-bisphosphate. Biochemistry 34, 9859–9864 (1995).

    Article  CAS  Google Scholar 

  20. Reuveny, E. et al. Activation of the cloned muscarinic potassium channel by G protein βγ subunits. Nature 370, 143–146 (1994).

    Article  ADS  CAS  Google Scholar 

  21. Huang, C.-L., Slesinger, P. A., Casey, P. J., Jan, Y. N. & Jan, L. Y. Evidence that direct binding of Gβγto the GIRK1 protein-gated inwardly rectifying K+ channel is important for channel activation. Neuron 15, 1133–1143 (1995).

    Article  CAS  Google Scholar 

  22. Huang, C.-L., Jan, Y. N. & Jan, L. Y. Binding of Gβγto multiple regions of G protein-gated inward rectifier K+ channels. FEBS Lett. 405, 291–298 (1997).

    Article  CAS  Google Scholar 

  23. Krapivinsky, G., Krapivinsky, L., Wickman, K. & Clapham, D. E. Gβγ binds directly to the G protein-gated K+ channel, IKACh. J. Biol. Chem. 270, 29059–29062 (1995).

    Article  CAS  Google Scholar 

  24. Janmey, P. A. Phosphoinositides and calcium as regulators of cellular actin assembly and disassembly. Annu. Rev. Physiol. 56, 169–191 (1994).

    Article  CAS  Google Scholar 

  25. Penniston, J. T. Plasma membrane Ca2+-pumping ATPases. Ann. NY Acad. Sci. 402, 291–303 (1982).

    Article  ADS  Google Scholar 

  26. Pitcher, J. A., Touhara, K., Payne, E. S. & Lefkowitz, R. J. Pleckstrin homology domain-mediated membrane association and activation of the β-adrenergic receptor kinase requires coordinate interaction with Gβγ and lipid. J. Biol. Chem. 270, 11707–11710 (1995).

    Article  CAS  Google Scholar 

  27. Tagliaalatela, M., Wible, B. A., Caporaso, R. & Brown, A. M. Specification of the pore properties by the carboxyl terminus of inward rectifying K+ channels. Science 264, 844–847 (1994).

    Article  ADS  Google Scholar 

  28. Clapham, D. E. & Neer, E. J. New roles for G protein βγ-dimers in transmembrane signaling. Nature 365, 403–406 (1993).

    Article  ADS  CAS  Google Scholar 

  29. Casey, P. J., Graziano, M. P. & Gilman, A. G. Gprotein βγ subunits from bovine brain and retina: equivalent catalytic support of ADP-ribosylation of α subunit by pertussis toxin but differential interactions with Gsα. Biochemistry 28, 611–616 (1989).

    Article  CAS  Google Scholar 

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Acknowledgements

We thank E. Phan for technical assistance; I. Bezprozvanny, C. Dessauer, D.Logothetis, C.-C. Lu, O. Moe, S. Muallem and H. Yin for discussions and advice; L. Jan for GIRK1 and ROMK1 antibodies; C. Dessauer and A. Gilman for Gαi1; P. Casey for Gβγ; and R. Alpern for support and encouragement. This work was supported by grants from the NKF of Texas (C.L.H.) and from the AHA and NIH (D.W.H.).

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Correspondence to Chou-Long Huang.

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Huang, CL., Feng, S. & Hilgemann, D. Direct activation of inward rectifier potassium channels by PIP2 and its stabilization by Gβγ. Nature 391, 803–806 (1998). https://doi.org/10.1038/35882

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