Functional characteristics of heteromeric Cx40-Cx43 gap junction channel formation

G. Trevor Cottrell, Yan Wu, Janis M. Burt

Research output: Contribution to journalArticlepeer-review

Abstract

Cx40:Cx43 expression ratio in A7r5 cells is augmented in growth stimulated vs. growth arrested conditions. To determine the impact of changing Cx40:Cx43 expression ratio on gap junction function, we have developed A7r5 cell lines that display Cx40:Cx43 ratios of 1:1 (6B5n) and 10:1 (A7r540C3). When Rin43 cells were paired with these coexpressing cells, there was an increasing asymmetry of voltage dependent gating as the Cx40:Cx43 ratio increased in the coexpressing cell. This asymmetry was opposite to that which is predicted by Cx40/Cx43 heterotypic channels. In addition, when Rin43 cells were paired with coexpressing cells there was a shift toward smaller single channel event amplitudes with increasing Cx40:Cx43 ratio in the coexpressing cell. Again, this is opposite to that which is predicted by Cx40/Cx43 heterotypic channels. In dye coupling experiments, 6B5N, A7r5, and A7r540C3 cells displayed charge and size selectivity that increased with increasing Cx40:Cx43 expression ratio. These data indicate that although the electrophysiological properties of heteromeric/heterotypic channels are not directly related to the proportions of Cx constituents that comprise the channel, the dye permeability data fit what would be predicted by an increase in Cx40:Cx43 ratio.

Original languageEnglish (US)
Pages (from-to)193-197
Number of pages5
JournalCell Adhesion and Communication
Volume8
Issue number4-6
StatePublished - Dec 1 2000

Keywords

  • Connexin
  • Heteromeric
  • Heterotypic
  • Permeability

ASJC Scopus subject areas

  • Cell Biology

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