Gene Symbol: cx55.5
Description: connexin 55.5
Alias: gap junction alpha-9 protein
Species: zebrafish

Top Publications

  1. Hussain M, Kremer M, Zoidl G, Dermietzel R. Transcriptional and translational regulation of zebrafish connexin 55.5 (zf.Cx.55.5) and connexin 52.6 (zf.Cx52.6). Cell Commun Adhes. 2003;10:227-31 pubmed
    ..5 and a promoter element in zfCx52.6 that showed different promoter activities in HeLa and N2A cells. Moreover, fusion constructs of zfCx55.5 with EGFP revealed the presence of a new isoform with an additional short exon I. ..
  2. Shields C, Klooster J, Claassen Y, Ul Hussain M, Zoidl G, Dermietzel R, et al. Retinal horizontal cell-specific promoter activity and protein expression of zebrafish connexin 52.6 and connexin 55.5. J Comp Neurol. 2007;501:765-79 pubmed
    ..6 and Cx55.5 promoters. Furthermore, these data provide the first proof at the protein level for retinal HC-specific connexins in the zebrafish. ..
  3. Zoidl G, Kremer M, Zoidl C, Bunse S, Dermietzel R. Molecular diversity of connexin and pannexin genes in the retina of the zebrafish Danio rerio. Cell Commun Adhes. 2008;15:169-83 pubmed publisher
    ..This result demonstrates the presence of two distinct gap junction type gene families and indicates a remarkable molecular and functional diversity of gap junction-mediated coupling in the fish retina. ..
  4. Klaassen L, Sun Z, Steijaert M, Bolte P, Fahrenfort I, Sjoerdsma T, et al. Synaptic transmission from horizontal cells to cones is impaired by loss of connexin hemichannels. PLoS Biol. 2011;9:e1001107 pubmed publisher
    ..This is an important step in resolving a long-standing debate about the unusual form of (ephaptic) synaptic transmission between horizontal cells and cones in the vertebrate retina. ..
  5. Prochnow N, Hoffmann S, Vroman R, Klooster J, Bunse S, Kamermans M, et al. Pannexin1 in the outer retina of the zebrafish, Danio rerio. Neuroscience. 2009;162:1039-54 pubmed publisher
    ..Together, these findings indicate that zfPanx1 displays properties similar to its mammalian homologues and can potentially play an important role in functions of the outer retina. ..
  6. Ul Hussain M, Zoidl G, Klooster J, Kamermans M, Dermietzel R. IRES-mediated translation of the carboxy-terminal domain of the horizontal cell specific connexin Cx55.5 in vivo and in vitro. BMC Mol Biol. 2008;9:52 pubmed publisher
    ..This suggests that Cx55.5 could be involved in gene regulation making structural plasticity at the PRC/HC/BPC complex feasible. ..
  7. Dermietzel R, Kremer M, Paputsoglu G, Stang A, Skerrett I, Gomes D, et al. Molecular and functional diversity of neural connexins in the retina. J Neurosci. 2000;20:8331-43 pubmed
    ..Moreover, although zfCx44.1 channels showed unitary conductance as high as any previously reported for junctional channels (nearly 300 pS), zfCx55. 5 and zfCx27.5 exhibited much lower unitary conductances (<60 pS). ..
  8. Sun Z, Risner M, van Asselt J, Zhang D, Kamermans M, McMahon D. Physiological and molecular characterization of connexin hemichannels in zebrafish retinal horizontal cells. J Neurophysiol. 2012;107:2624-32 pubmed publisher
    ..5 and Cx52.6 contribute to hemichannel currents, and that Cx55.5 may have an additional regulatory function enhancing the amplitude of hemichannel currents. ..
  9. Klaassen L, de Graaff W, van Asselt J, Klooster J, Kamermans M. Specific connectivity between photoreceptors and horizontal cells in the zebrafish retina. J Neurophysiol. 2016;116:2799-2814 pubmed publisher
    ..Electron microscopy confirms that H4 cells innervate cones. This indicates that rod-driven HCs process spectral information during photopic and luminance information during scotopic conditions. ..

More Information


  1. Gramage E, D Cruz T, Taylor S, Thummel R, Hitchcock P. Midkine-a protein localization in the developing and adult retina of the zebrafish and its function during photoreceptor regeneration. PLoS ONE. 2015;10:e0121789 pubmed publisher
    ..These data suggest that during photoreceptor regeneration Mdka regulates aspects of injury-induced cell proliferation. ..
  2. Watanabe M, Sawada R, Aramaki T, Skerrett I, Kondo S. The Physiological Characterization of Connexin41.8 and Connexin39.4, Which Are Involved in the Striped Pattern Formation of Zebrafish. J Biol Chem. 2016;291:1053-63 pubmed publisher
    ..Our results suggest that functional differences in Cx41.8 and Cx39.4 relate to spot or labyrinth mutant phenotypes and also provide evidence that these two connexins interact in vivo and in vitro. ..
  3. Ul Hussain M, Dermietzel R, Zoidl G. Characterization of the internal IRES element of the zebrafish connexin55.5 reveals functional implication of the polypyrimidine tract binding protein. BMC Mol Biol. 2008;9:92 pubmed publisher
    ..This observation is of considerable importance and may provide initial insight into molecular-functional relationships of electrical coupling in horizontal cells. ..
  4. Iovine M, Gumpert A, Falk M, Mendelson T. Cx23, a connexin with only four extracellular-loop cysteines, forms functional gap junction channels and hemichannels. FEBS Lett. 2008;582:165-70 pubmed
    ..Functional assays reveal that the Cx23 gap junctions are capable of sharing neurobiotin, and further, that Cx23 connexins form hemichannels in vitro. ..
  5. Greb H, Hermann S, Dirks P, Ommen G, Kretschmer V, Schultz K, et al. Complexity of gap junctions between horizontal cells of the carp retina. Neuroscience. 2017;340:8-22 pubmed publisher
    ..Moreover, BLAST searches of the preliminary carp genome, using novel sequences as query, suggest that most of the analyzed connexin genes are duplicated in carp. ..
  6. Sohl G, Joussen A, Kociok N, Willecke K. Expression of connexin genes in the human retina. BMC Ophthalmol. 2010;10:27 pubmed publisher
    ..Appropriate antibodies against Cx59 and Cx62 protein will clarify expression of these proteins in future studies. ..
  7. Wang T, Holzhausen L, Kramer R. Imaging an optogenetic pH sensor reveals that protons mediate lateral inhibition in the retina. Nat Neurosci. 2014;17:262-8 pubmed publisher
    ..These findings reveal that protons mediate lateral inhibition in the retina, raising the possibility that protons are unrecognized retrograde messengers elsewhere in the nervous system. ..
  8. Weber I, Ramos A, Strzyz P, Leung L, Young S, Norden C. Mitotic position and morphology of committed precursor cells in the zebrafish retina adapt to architectural changes upon tissue maturation. Cell Rep. 2014;7:386-97 pubmed publisher
    ..Furthermore, genetic interference with neuronal subset specification induces ectopic divisions of committed precursors, underlining the finding that progressing morphogenesis can effect precursor division position. ..
  9. Elliott S, Harvey Girard E, Giassi A, Maler L. Hippocampal-like circuitry in the pallium of an electric fish: Possible substrates for recursive pattern separation and completion. J Comp Neurol. 2017;525:8-46 pubmed publisher
    ..We discuss our results with respect to recent studies on fear avoidance conditioning in zebrafish and attention and spatial learning in a pulse gymnotiform fish. J. Comp. Neurol. 525:8-46, 2017. © 2016 Wiley Periodicals, Inc. ..