Connexon

In biology, a connexon, or hemichannel, is an assembly of six proteins called connexins that can be a part of a gap junction channel between the cytoplasm of two adjacent cells. The connexon is actually the hemichannel supplied by a cell on one side of the junction; two connexons from opposing cells normally come together to form the complete intercellular gap junction channel. However, in some cells, the hemichannel itself is active as a conduit between the cytoplasm and the extracellular space.