[Gap junctions--major structures promoting intercellular communication]

Gap junctions provide humoral and electric communication between the cells, thus contributing to their morpho-functional cooperation. Gap junction is formed by multiple intercellular channels, each of them being made by two closed hemichannels--connexons, that are oligomeric transmembrane proteins built by 6 subunits, belonging to connexin family. Permeability and electric conductivity of gap junction channels is determined by molecular peculiarities of connexins, their capacity for phosphorilation and by some extra- and intracellular factors. According to the current data, gap junctions in both cell cultures and tissues are dynamic structures with a short half-life period. Main mechanisms responsible for gap junction assembly and destruction have been discovered. These mechanisms were shown to depend upon peculiarities of differential genome activity and to be controlled by extra- and intracellular factors. The data on the gap junctions in the nervous system, heart and epidermis are presented.