How a gap junction maintains its structure.
Publication Type:Journal Article
Source:Nature, Volume 310, Number 5975, p.316–8 (1984)
Keywords:Animals, Biophysical Phenomena, Biophysics, Cell Membrane, Cell Membrane: ultrastructure, Electron, Freeze Fracturing, Intercellular Junctions, Intercellular Junctions: ultrastructure, Liver, Liver: ultrastructure, Macromolecular Substances, Membrane Proteins, Mice, Microscopy, Models, Molecular
<p>In gap junctions, identical membrane proteins are linked up in pairs (dyads) that bridge the extracellular space between two apposed cell membranes. Typically, several thousand of these dyads are aggregated in the plane of the membranes and form a junctional plaque with a distinct boundary. The question thus arises as to what maintains the dyads in an aggregated state. From a statistical mechanical analysis of the positions of dyads in a freeze-fracture electron micrograph, we report here that the aggregates are not maintained by an attractive force between pairs of dyads, but probably by the minimization of the repulsive force between apposed membranes. On the basis of this analysis we present a model for the structure of mature gap junctions as well as certain aspects of the formation and disassembly of gap junctions.</p>