Molecular physiology of gap junction channels.

1. Cloning and sequencing of cDNA encoding gap junction proteins (connexins) has allowed analysis of tissue- and stage-specific patterns of expression as well as the manipulation of expression of both wild-type and mutant connexin proteins. 2. These studies reveal that the 13 rodent connexins have different biophysical properties, such as unitary conductance and permeability/selectivity, are differentially sensitive to various gating stimuli and couple to one another with variable affinity. Moreover, the physiological roles of gap junction channels are being revealed, as both genetic and epigenetic human diseases are ascribed to aberrant gap junction expression, and as animal models are generated by genetic manipulation. 3. This symposium brought together physiological insights achieved through the use of molecular techniques, resulting in novel appreciation of the roles of gap junction channels in normal and pathological tissue function.