Are intercellular channel structures located in the plasma membranes of neighboring cells that mediate transfer of materials up to a molecular weight of 1,000 Da.
Transferred materials comprise ions, growth factors, and second messengers, among others. This transfer seems to be passive and nonselective. Channels (Ether à–go–go potassium channels) are formed by two hemichannels or connexons, every one embedded in the plasma membrane of adjacent cells and connected to each other to form hydrophilic, tube-like pores that allow transfer of material from one cell to another. In some cases, only one hemichannel is present allowing material to pass from the cell into the intercellular space. Individual channels accumulate in regions of the plasma membrane forming the typical plaques observed in the microscope. One plaque may contain up to 1,000 channels.
The connexons are formed by six molecules of connexinproteins, each of which contains four transmembrane...