Pflügers Archiv

, Volume 441, Issue 4, pp 481–488

Tissue distribution and functional expression of the human voltage-gated sodium channel β3 subunit

  • Edward B. Stevens
  • Peter J. Cox
  • Bhaval S. Shah
  • Alistair K. Dixon
  • Peter J. Richardson
  • Robert D. Pinnock
  • Kevin Lee
Original Article

DOI: 10.1007/s004240000449

Cite this article as:
Stevens, E., Cox, P., Shah, B. et al. Pflügers Arch - Eur J Physiol (2001) 441: 481. doi:10.1007/s004240000449

Abstract.

This study investigated the distribution of β3 in human tissues and the functional effects of the human β3 subunit on the gating properties of brain and skeletal muscle α subunits. Using RT-PCR of human cDNA panels, β3 message was detected in brain, heart, kidney, lung, pancreas and skeletal muscle. Both αIIA and SkM1 expressed in Xenopus oocytes inactivated with a time course described by two exponential components representing fast and slow gating modes, while co-expression of human β3 with αIIA or SkM1 significantly increased the proportion of channels operating by the fast gating mode. In the presence of β3 a greater proportion of αIIA or SkM1 current was described by the fast time constant for both inactivation and recovery from inactivation. β3 caused a hyperpolarizing shift in the voltage dependence of inactivation of αIIA and reduced the slope factor. The voltage dependence of inactivation of SkM1 was described by a double Boltzmann equation. However, SkM1 co-expressed with β3 was described by a single Boltzmann equation similar to one of the Boltzmann components for SkM1 expressed alone, with a small positive shift in V1/2 value and reduced slope factor. This is the first study demonstrating that β3 is expressed in adult mammalian skeletal muscle and can functionally couple to the skeletal muscle α subunit, SkM1.

β3 subunit Central nervous system Skeletal muscle Voltage-gated sodium channel Xenopus oocytes 

Copyright information

© Springer-Verlag 2000

Authors and Affiliations

  • Edward B. Stevens
    • 1
  • Peter J. Cox
    • 1
  • Bhaval S. Shah
    • 1
  • Alistair K. Dixon
    • 1
  • Peter J. Richardson
    • 2
  • Robert D. Pinnock
    • 1
  • Kevin Lee
    • 1
  1. 1.Parke-Davis Neuroscience Research Centre, Cambridge University Forvie Site, Robinson Way, Cambridge CB2 2QB, UK
  2. 2.Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QJ, UK

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