TY - JOUR
T1 - Molecular cloning and functional expression of zfCx52.6
T2 - A novel connexin with hemichannel-forming properties expressed in horizontal cells of the zebrafish retina
AU - Zoidl, Georg
AU - Bruzzone, Roberto
AU - Weickert, Svenja
AU - Kremer, Marian
AU - Zoidl, Christiane
AU - Mitropoulou, Georgia
AU - Srinivas, Miduturu
AU - Spray, David C.
AU - Dermietzel, Rolf
PY - 2004/1/23
Y1 - 2004/1/23
N2 - Gap junction-mediated electrical coupling contributes to synchronous oscillatory activities of neurons, and considerable progress has been made in defining the molecular composition of gap junction channels. In particular, cloning and functional expression 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 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 found that this novel fish connexin is expressed in horizontal cells in the inner nuclear layer of the retina. Functional expression of zfCx52.6 in neuroblastoma cells and Xenopus oocytes led to functional gap junctional channels and, in single oocytes, induced large non-junctional membrane currents indicative of the formation of hemichannels, which were inhibited in reversible fashion by raising extracellular Ca 2+ concentrations.
AB - Gap junction-mediated electrical coupling contributes to synchronous oscillatory activities of neurons, and considerable progress has been made in defining the molecular composition of gap junction channels. In particular, cloning and functional expression 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 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 found that this novel fish connexin is expressed in horizontal cells in the inner nuclear layer of the retina. Functional expression of zfCx52.6 in neuroblastoma cells and Xenopus oocytes led to functional gap junctional channels and, in single oocytes, induced large non-junctional membrane currents indicative of the formation of hemichannels, which were inhibited in reversible fashion by raising extracellular Ca 2+ concentrations.
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U2 - 10.1074/jbc.M304850200
DO - 10.1074/jbc.M304850200
M3 - Article
C2 - 14583621
AN - SCOPUS:1642273622
SN - 0021-9258
VL - 279
SP - 2913
EP - 2921
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 4
ER -