PUBLICATION

Molecular cloning and functional expression of zfCx52.6, a novel connexin with hemichannel forming properties expressed in the zebrafish retina

Authors
Zoidl, G., Bruzzone, R., Weickert, S., Kremer, M., Zoidl, C., Mitropoulou, G., Srinivas, M., Spray, D.C., and Dermietzel, R.
ID
ZDB-PUB-031031-3
Date
2004
Source
The Journal of biological chemistry   279(4): 2913-2921 (Journal)
Registered Authors
Zoidl, Georg
Keywords
electrical synapses, gap junctions, retina, neurons, hemichannels, horizontal cell
MeSH Terms
  • Amino Acid Sequence
  • Animals
  • Cloning, Molecular
  • Connexins/genetics*
  • Connexins/metabolism
  • Gap Junctions/metabolism
  • Humans
  • Molecular Sequence Data
  • Retina/metabolism*
  • Sequence Alignment
  • Xenopus
  • Zebrafish/metabolism*
  • Zebrafish Proteins/genetics*
  • Zebrafish Proteins/metabolism
PubMed
14583621 Full text @ J. Biol. Chem.
Abstract
Electrical synapses (gap junctions) in neuronal circuits have emerged as a major focus in the study of synchronous oscillatory activity of neurons. It has become clear that gap junction-mediated electrical coupling contributes to network properties and considerable progress has been made in defining the molecular composition of these intercellular channels. In particular, the cloning and functional expression studies of gap junction proteins [connexins (Cx)] from zebrafish retina have shown that this part of the brain possesses a high degree of connexin diversity that may account for differential functional properties of electrical synapses. Here, we report the cloning and functional characterization of a new connexin, designated as zebrafish Cx52.6 (zfCx52.6). This connexin shows little similarity to known connexins from fish and higher vertebrates. By combining in situ hybridization with Laser Capture Microdissection and RT-PCR, we obtained evidence that this novel fish connexin is expressed in the inner nuclear layer of the retina. Neuroblastoma cells transiently transfected with a zfCx52.6-EGFP fusion protein showed a strong expression of zfCx52.6, which was distributed throughout the cytoplasm in vesicular structures. Finally, functional expression in Xenopus oocytes showed that zfCx52.6 had the ability to assemble both gap junctional channels between paired cells and, in single oocytes, to induce large non-junctional membrane currents indicative of the formation of hemichannels, which were inhibited in reversible fashion by raising extracellular Ca2+ concentrations.
Genes / Markers
Figures
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Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping