PUBLICATION

IRES-mediated translation of the carboxy-terminal domain of the horizontal cell specific connexin Cx55.5 in vivo and in vitro

Authors
Ul-Hussain, M., Zoidl, G., Kloster, J., Kamermans, M., and Dermietzel, R.
ID
ZDB-PUB-080602-5
Date
2008
Source
BMC Molecular Biology   9: 52 (Journal)
Registered Authors
Kamermans, Maarten, Zoidl, Georg
Keywords
none
MeSH Terms
  • Animals
  • Base Sequence
  • Blotting, Western
  • Cell Line, Tumor
  • Cell Nucleus/metabolism
  • Cell Nucleus/ultrastructure
  • Connexins/chemistry
  • Connexins/genetics*
  • Connexins/metabolism*
  • HeLa Cells
  • Humans
  • Immunohistochemistry
  • Luciferases/genetics
  • Luciferases/metabolism
  • Mice
  • Microscopy, Immunoelectron
  • Molecular Sequence Data
  • NIH 3T3 Cells
  • Promoter Regions, Genetic/genetics
  • Protein Biosynthesis*
  • Protein Isoforms/genetics
  • Protein Isoforms/metabolism
  • Reverse Transcriptase Polymerase Chain Reaction
  • Ribosomes/chemistry
  • Ribosomes/metabolism*
  • Transcription, Genetic
  • Transfection
  • Zebrafish
PubMed
18505575 Full text @ BMC Mol. Biol.
Abstract
BACKGROUND: Changes of interneuronal coupling mediated by electrical synapse proteins in response to light adaptation and receptive field shaping are a paramount feature in the photoreceptor/horizontal cell/bipolar cell (PRC/HC/BPC) complex of the outer retina. The regulation of these processes is not fully understood at the molecular level but these processes may require information transfer to the nucleus by locally generated messengers. Electrical synapse proteins may comprise a feasible molecular determinant in such an information-laden signalling pathway. RESULTS: Connexin55.5 (Cx55.5) is a connexin with horizontal cell-restricted expression in zebrafish accumulating at dendritic sites within the PRC/HC/BPC complex in form of hemichannels where light-dependent plasticity occurs. Here we provide evidence for the generation of a carboxy-terminal domain of Cx55.5. The protein product is translated from the Cx55.5 mRNA by internal translation initiation from an in-frame ATG codon involving a putative IRES element localized in the coding region of Cx55.5. This protein product resembling an 11 kDa domain of Cx55.5 is partially located in the nucleus in vivo and in vitro. CONCLUSIONS: Our results demonstrate the generation of a second protein from the coding region of Cx55.5 by an IRES mediated process. The nuclear occurrence of a subfraction of this protein provides first evidence that this electrical synapse protein may participate in a putative cytoplasmic to nuclear signal transfer. This suggests that Cx55.5 could be involved in gene regulation making structural plasticity at the PRC/HC/BPC complex feasible.
Genes / Markers
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Human Disease / Model
Sequence Targeting Reagents
Fish
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Mapping