Clustering of connexin 43--enhanced green' fluorescent protein gap junction channels and functional coupling in living cells

摘要

Communication-incompetent cell lines were trans fected with con- nexin (Cx) 43 fused with enhanced green fluorescent protein EGFP) to examine the reletionn between Cx distribution determined by fluorescence microscopy and electrical coupling measured at single-channel resolution in living cell pairs. Cx43--EGFP channel properties were like those of wild-type Cx43 except for reduced sensitivity to trans junctional voltage. Cx43--EGFP clustered into plaques at locations of cell--cell contact. Coupling was always absent in the absence of plaques and even in the presence of small plaques. Plaques exceeding several hundred channels always con- ferred coupling. but only a small fraction of channels were func- tional. These data indicate that clustering may be a requirement for opening of gap junction channels.