Characterization of zebrafish Cx43.4 connexin and its channels
| Autor: | Thérèse Jarry-Guichard, Robert Weingart, I. Marics, Jean-Paul Briand, R. Veteikis, Daniel Gros, T. Desplantez |
|---|---|
| Rok vydání: | 2003 |
| Předmět: |
Xenopus
Connexin Cell Communication Membrane Potentials chemistry.chemical_compound Complementary DNA Chlorocebus aethiops Animals Humans Tissue Distribution Cloning Molecular Zebrafish Lucifer yellow COS cells biology Electric Conductivity Gap Junctions Membrane Proteins General Medicine Transfection Zebrafish Proteins biology.organism_classification Molecular biology Recombinant Proteins Cell biology Molecular Weight Electrophysiology chemistry COS Cells HeLa Cells |
| Zdroj: | Experimental physiology. 88(6) |
| ISSN: | 0958-0670 |
| Popis: | Connexins (Cx) form intercellular junctional channels which are responsible for metabolic and electrical coupling. We report here on the biochemical and immunohistochemical characterization of zebrafish connexin zfCx43.4, an orthologue of mammalian and avian Cx45, and the electrophysiological properties of junctional channels formed by this protein. The investigations were performed on transfected COS-7 cells or HeLa cells. Using site-directed antibodies, zfCx43.4 cDNA (GenBank accession no. X96712) was demonstrated to code for a protein with a M(r) of 45 000. In transfected cells, zfCx43.4 was localized in cell-cell contact areas as expected for a gap junction protein. zfCx43.4 channels were shown to transfer Lucifer Yellow. The multichannel currents were sensitive to the transjunctional voltage (V(j)). Their properties were consistent with a two-state model and yielded the following Boltzmann parameters for negative/positive V(j): V(j,0) = -38.4/41.9 mV; g(j,min) = 0.19/0.18; z = 2.6/2.3. These parameters deviate somewhat from those of zfCx43.4 channels expressed in Xenopus oocytes and from those of Cx45, an orthologue of zfCx43.4, expressed in mammalian cells or Xenopus oocytes. Conceivably, the subtle differences may reflect differences in experimental methods and/or in the expression system. The single channel currents yielded two prominent levels attributable to a main conductance state (gamma(j,main) = 33.2 +/- 1.5 pS) and a residual conductance state (gamma(j,residual) = 11.9 +/- 0.6 pS). |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Plný text