Figure 22-8. Structure of gap junctions.

Figure 22-8Structure of gap junctions

(a) In this model, a gap junction is a cluster of channels between two plasma membranes that are separated by a gap of about 2 – 3 nm. (b) Both membranes contain connexon hemichannels, cylinders of six dumbbell-shaped connexin subunits. (c) Each connexin subunit has four transmembrane α helices. Two connexons join in the gap between the cells to form a gap-junction channel, 1.5 – 2.0 nm in diameter, that connects the cytoplasm of the two cells.

From: Section 22.1, Cell-Cell Adhesion and Communication

Cover of Molecular Cell Biology
Molecular Cell Biology. 4th edition.
Lodish H, Berk A, Zipursky SL, et al.
New York: W. H. Freeman; 2000.
Copyright © 2000, W. H. Freeman and Company.

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