Innexin-3 forms connexin-like intercellular channels

J Cell Sci. 1999 Jul;112 ( Pt 14):2391-6. doi: 10.1242/jcs.112.14.2391.


Innexins comprise a large family of genes that are believed to encode invertebrate gap junction channel-forming proteins. However, only two Drosophila innexins have been directly tested for the ability to form intercellular channels and only one of those was active. Here we tested the ability of Caenorhabditis elegans family members INX-3 and EAT-5 to form intercellular channels between paired Xenopus oocytes. We show that expression of INX-3 but not EAT-5, induces electrical coupling between the oocyte pairs. In addition, analysis of INX-3 voltage and pH gating reveals a striking degree of conservation in the functional properties of connexin and innnexin channels. These data strongly support the idea that innexin genes encode intercellular channels.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Caenorhabditis elegans / genetics
  • Caenorhabditis elegans / metabolism
  • Caenorhabditis elegans Proteins*
  • Cell Communication
  • Connexins / genetics
  • Connexins / metabolism*
  • Female
  • Gap Junctions / metabolism
  • Gene Expression
  • Genes, Helminth
  • Helminth Proteins / genetics
  • Helminth Proteins / metabolism*
  • Hydrogen-Ion Concentration
  • In Vitro Techniques
  • Ion Channel Gating
  • Ion Channels / genetics
  • Ion Channels / metabolism*
  • Membrane Potentials
  • Oocytes / metabolism
  • Xenopus


  • Caenorhabditis elegans Proteins
  • Connexins
  • Helminth Proteins
  • Ion Channels
  • eat-5 protein, C elegans