Journal of Bioenergetics and Biomembranes

, Volume 28, Issue 4, pp 327–337

Size and selectivity of gap junction channels formed from different connexins

  • Richard D. Veenstra

DOI: 10.1007/BF02110109

Cite this article as:
Veenstra, R.D. J Bioenerg Biomembr (1996) 28: 327. doi:10.1007/BF02110109


Gap junction channels have long been viewed as static structures containing a large-diameter, aqueous pore. This pore has a high permeability to hydrophilic molecules of ≈900 daltons in molecular weight and a weak ionic selectivity. The evidence leading to these conclusions is reviewed in the context of more recent observations primarily coming from unitary channel recordings from transfected connexin channels expressed in communication-deficient cell lines. What is emerging is a more diverse view of connexin-specific gap junction channel structure and function where electrical conductance, ionic selectivity, and dye permeability vary by one full order of magnitude or more. Furthermore, the often held contention that channel conductance and ionic or molecular selectivity are inversely proportional is refuted by recent evidence from five distinct connexin channels. The molecular basis for this diversity of channel function remains to be identified for the connexin family of gap junction proteins.

Key words

Connexinchannel conductanceionic selectivitydye permeability6-carboxyfluorescein2′,7′-dichlorofluoresceinLucifer Yellowbiionic reversal potentialsconductance ratiosGoldman-Hodgkin-Katz voltage and current equations

Copyright information

© Plenum Publishing Corporation 1996

Authors and Affiliations

  • Richard D. Veenstra
    • 1
  1. 1.Department of PharmacologySUNY Health Science Center at SyracuseSyracuse