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Structure of a complex between a voltage-gated calcium channel β-subunit and an α-subunit domain

Abstract

Voltage-gated calcium channels (CaVs) govern muscle contraction, hormone and neurotransmitter release, neuronal migration, activation of calcium-dependent signalling cascades, and synaptic input integration1. An essential CaV intracellular protein, the β-subunit (CaVβ)1,2, binds a conserved domain (the α-interaction domain, AID) between transmembrane domains I and II of the pore-forming α1 subunit3 and profoundly affects multiple channel properties such as voltage-dependent activation2, inactivation rates2, G-protein modulation4, drug sensitivity5 and cell surface expression6,7. Here, we report the high-resolution crystal structures of the CaVβ2a conserved core, alone and in complex with the AID. Previous work suggested that a conserved region, the β-interaction domain (BID), formed the AID-binding site3,8; however, this region is largely buried in the CaVβ core and is unavailable for protein–protein interactions. The structure of the AID–CaVβ2a complex shows instead that CaVβ2a engages the AID through an extensive, conserved hydrophobic cleft (named the α-binding pocket, ABP). The ABP–AID interaction positions one end of the CaVβ near the intracellular end of a pore-lining segment, called IS6, that has a critical role in CaV inactivation9,10. Together, these data suggest that CaVβs influence CaV gating by direct modulation of IS6 movement within the channel pore.

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Figure 1: Structure of the CaVβ2a–CaV1.2 AID complex.
Figure 2: Structural comparisons between PSD-95 (gold) and CaVβ2a (blue).
Figure 3: Features of the AID–CaVβ2a interaction and location of the previously described BID.
Figure 4: AID–ABP interactions.
Figure 5: Cartoon of proposed model for how CaVβ affects CaVα1 gating.

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References

  1. Catterall, W. A. Structure and regulation of voltage-gated Ca2+ channels. Annu. Rev. Cell Dev. Biol. 16, 521–555 (2000)

    Article  CAS  Google Scholar 

  2. Dolphin, A. C. β-subunits of voltage-gated calcium channels. J. Bioenerg. Biomembr. 35, 599–620 (2003)

    Article  CAS  Google Scholar 

  3. Pragnell, M. et al. Calcium channel β-subunit binds to a conserved motif in the I–II cytoplasmic linker of the α1-subunit. Nature 368, 67–70 (1994)

    Article  ADS  CAS  PubMed Central  Google Scholar 

  4. Dolphin, A. C. G protein modulation of voltage-gated calcium channels. Pharmacol. Rev. 55, 607–627 (2003)

    Article  CAS  Google Scholar 

  5. Hering, S. β-Subunits: fine tuning of Ca2+ channel block. Trends Pharmacol. Sci. 23, 509–513 (2002)

    Article  CAS  Google Scholar 

  6. Bichet, D. et al. The I–II loop of the Ca2+ channel α1 subunit contains an endoplasmic reticulum retention signal antagonized by the β subunit. Neuron 25, 177–190 (2000)

    Article  CAS  Google Scholar 

  7. Beguin, P. et al. Regulation of Ca2+ channel expression at the cell surface by the small G-protein kir/Gem. Nature 411, 701–706 (2001)

    Article  ADS  CAS  Google Scholar 

  8. De Waard, M., Scott, V. E., Pragnell, M. & Campbell, K. P. Identification of critical amino acids involved in α1-β interaction in voltage-dependent Ca2+ channels. FEBS Lett. 380, 272–276 (1996)

    Article  CAS  Google Scholar 

  9. Stotz, S. C., Hamid, J., Spaetgens, R. L., Jarvis, S. E. & Zamponi, G. W. Fast inactivation of voltage-dependent calcium channels. A hinged-lid mechanism? J. Biol. Chem. 275, 24575–24582 (2000)

    Article  CAS  PubMed Central  Google Scholar 

  10. Zhang, J. F., Ellinor, P. T., Aldrich, R. W. & Tsien, R. W. Molecular determinants of voltage-dependent inactivation in calcium channels. Nature 372, 97–100 (1994)

    Article  ADS  CAS  Google Scholar 

  11. Dimitratos, S. D., Woods, D. F., Stathakis, D. G. & Bryant, P. J. Signaling pathways are focused at specialized regions of the plasma membrane by scaffolding proteins of the MAGUK family. Bioessays 21, 912–921 (1999)

    Article  CAS  PubMed Central  Google Scholar 

  12. Tavares, G. A., Panepucci, E. H. & Brunger, A. T. Structural characterization of the intramolecular interaction between the SH3 and guanylate kinase domains of PSD-95. Mol. Cell 8, 1313–1325 (2001)

    Article  CAS  Google Scholar 

  13. McGee, A. W. et al. Structure of the SH3-guanylate kinase module from PSD-95 suggests a mechanism for regulated assembly of MAGUK scaffolding proteins. Mol. Cell 8, 1291–1301 (2001)

    Article  CAS  Google Scholar 

  14. Paarmann, I., Spangenberg, O., Lavie, A. & Konrad, M. Formation of complexes between Ca2+.calmodulin and the synapse-associated protein SAP97 requires the SH3 domain-guanylate kinase domain-connecting HOOK region. J. Biol. Chem. 277, 40832–40838 (2002)

    Article  CAS  Google Scholar 

  15. Witcher, D. R., De Waard, M., Liu, H., Pragnell, M. & Campbell, K. P. Association of native Ca2+ channel β subunits with the α1 subunit interaction domain. J. Biol. Chem. 270, 18088–18093 (1995)

    Article  CAS  Google Scholar 

  16. De Waard, M., Pragnell, M. & Campbell, K. P. Ca2+ channel regulation by a conserved β subunit domain. Neuron 13, 495–503 (1994)

    Article  CAS  Google Scholar 

  17. Berrou, L., Klein, H., Bernatchez, G. & Parent, L. A specific tryptophan in the I–II linker is a key determinant of β-subunit binding and modulation in Ca(V)2.3 calcium channels. Biophys. J. 83, 1429–1442 (2002)

    Article  ADS  CAS  PubMed Central  Google Scholar 

  18. Opatowsky, Y., Chomsky-Hecht, O., Kang, M. G., Campbell, K. P. & Hirsch, J. A. The voltage-dependent calcium channel β subunit contains two stable interacting domains. J. Biol. Chem. 278, 52323–52332 (2003)

    Article  CAS  PubMed Central  Google Scholar 

  19. Kochegarov, A. A. Pharmacological modulators of voltage-gated calcium channels and their therapeutical application. Cell Calcium 33, 145–162 (2003)

    Article  CAS  Google Scholar 

  20. De Waard, M. et al. Direct binding of G-protein βγ complex to voltage-dependent calcium channels. Nature 385, 446–450 (1997)

    Article  ADS  CAS  PubMed Central  Google Scholar 

  21. Zhang, J. F., Ellinor, P. T., Aldrich, R. W. & Tsien, R. W. Multiple structural elements in voltage-dependent Ca2+ channels support their inhibition by G proteins. Neuron 17, 991–1003 (1996)

    Article  CAS  PubMed Central  Google Scholar 

  22. Qin, N., Platano, D., Olcese, R., Stefani, E. & Birnbaumer, L. Direct interaction of Gβγ with a C-terminal Gβγ-binding domain of the Ca2+ channel α1 subunit is responsible for channel inhibition by G protein-coupled receptors. Proc. Natl Acad. Sci. USA 94, 8866–8871 (1997)

    Article  ADS  CAS  PubMed Central  Google Scholar 

  23. Ivanina, T., Blumenstein, Y., Shistik, E., Barzilai, R. & Dascal, N. Modulation of L-type Ca2+ channels by Gβγ and calmodulin via interactions with N and C termini of α1C. J. Biol. Chem. 275, 39846–39854 (2000)

    Article  CAS  PubMed Central  Google Scholar 

  24. Miyazawa, A., Fujiyoshi, Y. & Unwin, N. Structure and gating mechanism of the acetylcholine receptor pore. Nature 424, 949–955 (2003)

    Article  ADS  Google Scholar 

  25. Jiang, Y. et al. The open pore conformation of potassium channels. Nature 417, 523–526 (2002)

    Article  ADS  CAS  Google Scholar 

  26. Herlitze, S., Hockerman, G. H., Scheuer, T. & Catterall, W. A. Molecular determinants of inactivation and G protein modulation in the intracellular loop connecting domains I and II of the calcium channel α1A subunit. Proc. Natl Acad. Sci. USA 94, 1512–1516 (1997)

    Article  ADS  CAS  PubMed Central  Google Scholar 

  27. Berrou, L., Bernatchez, G. & Parent, L. Molecular determinants of inactivation within the I–II linker of α1E (CaV2.3) calcium channels. Biophys. J. 80, 215–228 (2001)

    Article  CAS  PubMed Central  Google Scholar 

  28. Restituito, S. et al. The β2a subunit is a molecular groom for the Ca2+ channel inactivation gate. J. Neurosci. 20, 9046–9052 (2000)

    Article  CAS  PubMed Central  Google Scholar 

  29. Walker, D. et al. A new β subtype-specific interaction in α1A subunit controls P/Q-type Ca2+ channel activation. J. Biol. Chem. 274, 12383–12390 (1999)

    Article  CAS  Google Scholar 

  30. Walker, D., Bichet, D., Campbell, K. P. & De Waard, M. A β4 isoform-specific interaction site in the carboxyl-terminal region of the voltage-dependent Ca2+ channel α1A subunit. J. Biol. Chem. 273, 2361–2367 (1998)

    Article  CAS  Google Scholar 

Download references

Acknowledgements

We thank J. M. Berger, K. Brejc, D. Fass, D. Julius, E. A. Lumpkin and B. A. Schulman for comments on the manuscript; J. Holton at beamline 8.3.1 at the Advanced Light Source for help with data collection; R. W. Tsien and D. T. Yue for the calcium channel clones; and members of the Minor laboratory for support at all stages of this work. This work was supported by awards to D.L.M. from the McKnight Foundation for Neuroscience, the March of Dimes Basil O'Connor Scholar program, the Alfred P. Sloan Foundation, and the Rita Allen Foundation. D.L.M. is a McKnight Foundation Scholar, an Alfred P. Sloan Research Fellow and a Rita Allen Foundation Scholar.

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Correspondence to Daniel L. Minor Jr.

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Supplementary information

Supplementary Information

Includes Supplementary Figure 1: Schematic representation of interactions between the AID peptide and Cavβ2a; Supplementary Figure 2: Location of AID residues implicated in Gβγ binding; Supplementary Table 1: Data collection, phasing and refinement; Supplementary Table 2: Accessibilities of AID residues in the AID-CaVβ2a complex; Supplementary Methods; Supplementary References. (PDF 419 kb)

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Van Petegem, F., Clark, K., Chatelain, F. et al. Structure of a complex between a voltage-gated calcium channel β-subunit and an α-subunit domain. Nature 429, 671–675 (2004). https://doi.org/10.1038/nature02588

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