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Structure and closure of connexin gap junction channels
Author(s) -
Oshima Atsunori
Publication year - 2014
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/j.febslet.2014.01.042
Subject(s) - connexin , gating , gap junction , context (archaeology) , biophysics , chemistry , ion channel , phosphorylation , electrophysiology , microbiology and biotechnology , biology , neuroscience , biochemistry , intracellular , receptor , paleontology
Connexin gap junctions comprise assembled channels penetrating two plasma membranes for which gating regulation is associated with a variety of factors, including voltage, pH, Ca 2+ , and phosphorylation. Functional studies have established that various parts of the connexin peptides are related to channel closure and electrophysiology studies have provided several working models for channel gating. The corresponding structural models supporting these findings, however, are not sufficient because only small numbers of closed connexin structures have been reported. To fully understand the gating mechanisms, the channels should be visualized in both the open and closed states. Electron crystallography and X‐ray crystallography studies recently revealed three‐dimensional structures of connexin channels in a couple of states in which the main difference is the conformation of the N‐terminal domain, which have helped to clarify the structure in regard to channel closure. Here the closure models for connexin gap junction channels inferred from structural and functional studies are described in the context of each domain of the connexin protein associated with gating modulation.