The Journal of Membrane Biology

, Volume 184, Issue 1, pp 35–43

Tissue-specific Expression and Gabapentin-Binding Properties of Calcium Channel α2δ Subunit Subtypes

Authors

  • H.C.  Gong
    • Department of Molecular Sciences, Pfizer Global Research and Development, Ann Arbor, MI 48105, USA
  • J.  Hang
    • Department of Molecular Sciences, Pfizer Global Research and Development, Ann Arbor, MI 48105, USA
  • W.  Kohler
    • Department of Molecular Sciences, Pfizer Global Research and Development, Ann Arbor, MI 48105, USA
  • L.  Li
    • Department of Molecular Sciences, Pfizer Global Research and Development, Ann Arbor, MI 48105, USA
  • T.-Z.  Su
    • Department of Molecular Sciences, Pfizer Global Research and Development, Ann Arbor, MI 48105, USA

DOI: 10.1007/s00232-001-0072-7

Cite this article as:
Gong, H., Hang, J., Kohler, W. et al. J. Membrane Biol. (2001) 184: 35. doi:10.1007/s00232-001-0072-7

Abstract.

We report here the tissue-specific expression and gabapentin-binding properties of calcium channel α2δ subunits. Northern blot analysis demonstrated that human α2δ-1, -2, and -3 mRNA all had high levels of expression in brain, heart and skeletal muscle. However, the highest expression of human α2δ-2 mRNA was found in lung. Human α2δ-1, -2, and -3 mRNAs were detected in all portions of brain tested. Western blotting revealed that α2δ-2 protein was predominantly expressed in cerebellar cortex (brain) and undetectable in lung. The dissociation between mRNA and protein levels of human α2δ-2 in lung suggests possible post-transcriptional regulation. Although mouse α2δ-1 proteins exhibited a similar tissue distribution profile as that of human, tissue distribution of mouse α2δ-2 and -3 mRNA revealed a different profile. Mouse α2δ-3 mRNA was restricted to brain and mouse α2δ-2 mRNA was not detectable in lung. Gel electrophoresis under a reduced condition resulted in a mobility shift of both α2δ-1 and α2δ-2 proteins, suggesting that α2 and δ of α2δ-2 protein are linked by disulfide bond as are α2 and δ of α2δ-1. Scatchard plots revealed a single population of gabapentin binding sites for human α2δ-2 with the KD value twofold higher than that of porcine α2δ-1 (156 ± 25 nm vs. 72 ± 9 nm). Inhibition of gabapentin binding to α2δ-2 by selected amino acids and gabapentin analogs produced a binding profile similar, but not identical to that of α2δ-1.

Key words:α2δ— calcium channel subunits — gabapentin — anticonvulsant

Copyright information

© 2001 Springer-Verlag New York Inc.